Valdir Garcia | UNIFEB - Academia.edu (original) (raw)

Papers by Valdir Garcia

Research paper thumbnail of Periodontal Plastic Surgery Associated With Treatment for the Removal of Gingival Overgrowth

Journal of Periodontology, 2006

Excisional biopsies of gingival overgrowths, performed with safety margins, frequently result in ... more Excisional biopsies of gingival overgrowths, performed with safety margins, frequently result in mucogingival defects. These defects may produce esthetic problems and increase the chances of dentin hyperesthesia and its possibility of hindering oral hygiene. Two clinical cases are reported in which gingival overgrowths were removed by excisional biopsy, resulting in unsightly defects. The first clinical case presents an invasive approach for the treatment of a recurrent pyogenic granuloma in the anterior maxilla, and the second depicts a complete removal of a peripheral odontogenic fibroma in the posterior maxilla. In both situations, the soft-tissue defects were repaired by periodontal plastic surgery, including a laterally positioned flap and a coronally positioned flap, respectively. Periodontal plastic surgery successfully restored the defects that resulted from biopsies, and no recurrence has been noticed in the 5-year postoperative follow-up period. The combination of biopsy and periodontal plastic surgery in a one-step procedure seems to be suitable to remove gingival overgrowths in most areas of the mouth, regardless of esthetic significance. Such procedures seem to restore gingival health, encourage healing, and create both esthetics and function in the excised area.

Research paper thumbnail of Treatment of Experimental Periodontal Disease by Photodynamic Therapy in Rats With Diabetes

Journal of Periodontology, 2008

Research paper thumbnail of A Histologic and Histometric Assessment of the Influence of Nicotine on Alveolar Bone Loss in Rats

Journal of Periodontology, 2007

Background: Cigarette smoking has long been recognized as a risk factor for periodontal disease. ... more Background: Cigarette smoking has long been recognized as a risk factor for periodontal disease. The aim of this study was to perform quantitative and qualitative analyses of bone loss in the furcation region of periodontally healthy rats after daily systemic administration of nicotine or saline solution.

Research paper thumbnail of Influence of Photodynamic Therapy on the Development of Ligature-Induced Periodontitis in Rats

Journal of Periodontology, 2007

Research paper thumbnail of Morphologic analysis, by means of scanning electron microscopy, of the effect of Er: YAG laser on root surfaces submitted to scaling and root planing

The pur po se of this study was to morp ho lo gi cally eva lu a te, by me ans of scan ning elec t... more The pur po se of this study was to morp ho lo gi cally eva lu a te, by me ans of scan ning elec tron mi cros copy, the ef fects of Er:YAG la ser on the tre at ment of root sur fa ces sub mit ted to sca ling and root pla ning with con ven ti o nal pe ri odon tal ins tru ments. Eigh te en root sur fa ces (n = 18), which had been pre vi ously sca led and pla ned, were as sig ned to 3 groups (n = 6). The con trol Group (G1) re ce i ved no furt her tre at ment; Group 2 (G2) was ir ra di a ted with Er:YAG la ser (2.94 µm), with 47 mJ/10 Hz, in a fo cu sed mode with air/wa ter spray du ring 15 s and with 0.57 J/cm 2 of flu ency per pul se; Group 3 (G 3) was ir ra di a ted with Er:YAG la ser (2.94 µm), with 83 mJ/10 Hz, in a fo cu sed mode with air/wa ter spray du ring 15 s and with 1.03 J/cm 2 of flu ency per pul se. We con clu ded that the pa ra me ters adop ted for Group 3 remo ved the sme ar la yer from the root sur fa ce, ex po sing the den ti nal tu bu les. Although no fis su res, cracks or car bo nized are as were ob ser ved, an ir re gu lar sur fa ce was pro du ced by Er:YAG la ser ir ra di a ti on. Thus, the bi o com pa ti bi lity of the ir ra di a ted root sur fa ce, wit hin the pe ri o don tal he a ling pro cess, must be as ses s ed.

Research paper thumbnail of Effect of platelet-rich plasma on bone healing of autogenous bone grafts in critical-size defects

Journal of Clinical Periodontology, 2009

Aim: This study histologically analysed the effect of autogenous platelet-rich plasma (PRP), prep... more Aim: This study histologically analysed the effect of autogenous platelet-rich plasma (PRP), prepared according to a new semiautomatic system, on healing of autogenous bone (AB) grafts placed in surgically created critical-size defects (CSD) in rabbit calvaria.Material and Methods: Sixty rabbits were divided into three groups: C, AB and AB/PRP. A CSD was created in the calvarium of each animal. In Group C (control), the defect was filled by blood clot only. In Group AB (autogenous bone graft), the defect was filled with particulate autogenous bone. In Group AB/PRP (autogenous bone graft with platelet-rich plasma), it was filled with particulate autogenous bone combined with PRP. All groups were divided into subgroups (n=10) and euthanized at 4 or 12 weeks post-operatively. Histometric and histologic analyses were performed. Data were statistically analysed (anova, t-test, p<0.05).Results: Group C presented significantly less bone formation compared with Group AB and AB/PRP in both periods of analysis (p<0.001). At 4 weeks, Group AB/PRP showed a statistically greater amount of bone formation than Group AB (64.44 ± 15.0%versus 46.88 ± 14.15%; p=0.0181). At 12 weeks, no statistically significant differences were observed between Groups AB and AB/PRP (75.0 ± 8.11%versus 77.90 ± 8.13%; p>0.05). It is notable that the amount of new bone formation in Group AB/PRP at 4 weeks was similar to that of Group AB at 12 weeks (p>0.05).Conclusion: Within its limitation, the present study has indicated that (i) AB and AB/PRP significantly improved bone formation and (ii) a beneficial effect of PRP was limited to an initial healing period of 4 weeks.

Research paper thumbnail of Treatment of Ligature-Induced Peri-Implantitis by Lethal Photosensitization and Guided Bone Regeneration: A Preliminary Histologic Study in Dogs

Journal of Periodontology, 2003

This study evaluated the treatment of ligature-induced peri-implantitis using guided tissue regen... more This study evaluated the treatment of ligature-induced peri-implantitis using guided tissue regeneration (GTR) around submerged and nonsubmerged implants in beagle dogs. Two titanium implants were placed bilaterally in the premolar regions of the mandible in each of 10 beagle dogs. Cotton floss ligatures were placed around the implant necks and no oral hygiene procedures were performed for 5 months. Periodontal surgery was performed, and in five dogs (submerged group) the abutments were removed and an e-PTFE barrier was placed to cover the test implants and their adjacent osseous defects, while the control implants received no barriers. In the other five dogs (nonsubmerged group), flap surgery was performed without removing the abutments. In the test sites, an e-PTFE barrier was placed around the abutment and adjacent defects, while on the control sites no barrier was placed. Nondecalcified specimens were prepared using standard histologic methods and analyzed. No differences were found between any of the clinical parameters in both the control and experimental sites from the submerged and nonsubmerged groups. Histologic and histomorphometric analyses also revealed no significant differences between groups with regard to new bone formation. In the experimental (GTR) groups, however, the amount of regenerated connective tissue was significantly greater than on the control groups. Under the conditions of this study, the treatment of peri-implantitis using GTR did not enhance clinical parameters or bone formation around "diseased" implants. (I NT J ORAL MAXILLOFAC IMPLANTS 1993;8 282-293.)

Research paper thumbnail of Treatment of experimental periodontal disease by photodynamic therapy in immunosuppressed rats

Journal of Clinical Periodontology, 2009

Background and Objective: The aim of this study was to compare photodynamic therapy (PDT) as an a... more Background and Objective: The aim of this study was to compare photodynamic therapy (PDT) as an adjunctive treatment of induced periodontitis with scaling and root planing (SRP) in dexamethasone-inhibited rats.Material and Methods: The animals were divided into two groups: ND (n=90), saline solution treatment; D (n=90), dexamethasone treatment. In the ND and D Groups, periodontal disease was ligature-induced at the first mandibular molar. After 7 days, the ligature was removed and all animals received SRP and were divided according to the following treatments: SRP, saline solution; Toluidine Blue-O (TBO), phenothiazinium dye; and PDT, TBO and laser irradiation. Ten animals in each treatment were killed at 7, 15 and 30 days. The radiographic and histometric values were statistically analysed.Results: In the ND and D Groups, radiographic analysis showed less bone loss in animals treated by PDT in all the experimental periods than SRP and TBO at 15 days (p<0.05). After a histometric analysis was carried out in the ND and D groups, the animals treated by PDT showed less bone loss in all periods than SRP and TBO after 15 days (p<0.05).Conclusions: The PDT was an effective adjunctive treatment of induced periodontitis compared with SRP in dexamethasone-inhibited rats.

Research paper thumbnail of Comparative analysis of root surface smear layer removal by different etching modalities or erbium:yttrium–aluminum–garnet laser irradiation. A scanning electron microscopy study

Lasers in Medical Science, 2010

The purpose of this study was to evaluate the effect of erbium:yttrium–aluminum–garnet (Er:YAG) l... more The purpose of this study was to evaluate the effect of erbium:yttrium–aluminum–garnet (Er:YAG) laser (2.94 μm) irradiation on the removal of root surface smear layer of extracted human teeth and to compare its efficacy with that of citric acid, ethylenediamine tetra-acetic acid (EDTA), or a gel containing a mixture of tetracycline hydrochloride (HCl) and citric acid, using scanning electron microscopy (SEM). Thirty human dentin specimens were randomly divided into six groups: G1 (control group), irrigated with 10 ml of physiologic saline solution; G2, conditioned with 24% citric acid gel; G3, conditioned with 24% EDTA gel; G4, conditioned with a 50% citric acid and tetracycline gel; G5, irradiated with Er:YAG laser (47 mJ/10 Hz/5.8 J/cm2/pulse); G6, irradiated with Er:YAG laser (83 mJ/10 Hz/10.3 J/cm2/pulse). Electron micrographs were obtained and analyzed according to a rating system. Statistical analysis was conducted with Kruskal–Wallis and Mann–Whitney tests (P < 0.05). G1 was statistically different from all the other groups; no statistically significant differences were observed between the Er:YAG laser groups and those undergoing the other treatment modalities. When the two Er:YAG laser groups were compared, the fluency of G6 was statistically more effective in smear layer removal than the one used in G5 (Mann–Whitney test, P < 0.01). Root surfaces irradiated by Er:YAG laser had more irregular contours than those treated by chemical agents. It can be concluded that all treatment modalities were effective in smear layer removal. The results of our study suggest that the Er:YAG laser can be safely used to condition diseased root surfaces effectively. Furthermore, the effect of Er:YAG laser irradiation on root surfaces should be evaluated in vivo so that its potential to enhance the healing of periodontal tissues can be assessed.

Research paper thumbnail of In Vivo Effect of Photodynamic Therapy on Periodontal Bone Loss in Dental Furcations

Journal of Periodontology, 2008

The purpose of this study was to histometrically evaluate the influence of photodynamic therapy o... more The purpose of this study was to histometrically evaluate the influence of photodynamic therapy on bone loss in furcation areas in rats with experimentally induced periodontal disease. Ligatures were placed on the first mandibular molar in rats. Then the animals were divided into four groups: control group = no treatment; methylene blue group (MB) = treated topically with methylene blue (100 microg/ml); laser group (LLLT) = treated with low-level laser therapy; and photodynamic therapy group (PDT) = treated topically with MB followed by LLLT (4.5 J/cm(2)). Rats from all groups were sacrificed at 7, 15, or 30 days postoperatively. The area of bone loss in the furcation region of the first molar was histometrically analyzed. Data were analyzed statistically (analysis of variance and Bonferroni tests; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). The PDT group demonstrated less bone loss compared to the other groups at 7 days (1.986 +/- 0.417 mm(2)); at 15 days, the PDT (1.641 +/- 0.115 mm(2)) and MB groups (1.991 +/- 0.294 mm(2)) demonstrated less bone loss compared to the control (4.062 +/- 0.416 mm(2)) and LLLT (2.641 +/- 0.849 mm(2)) groups. Within the parameters used in this study, PDT may be an effective alternative for control of bone loss in furcation areas in periodontitis.

Research paper thumbnail of Clinical and microbiological effects of photodynamic therapy associated with nonsurgical periodontal treatment. A 6-month follow-up

Lasers in Medical Science

Experimental studies in animals and in vitro have shown the usefulness of photodynamic therapy (P... more Experimental studies in animals and in vitro have shown the usefulness of photodynamic therapy (PDT) as an adjunct to periodontal treatment. The aim of this study was to evaluate the long-term clinical and microbiological effects of PDT associated with nonsurgical periodontal treatment. Three sites in each of 33 patients with chronic periodontitis were randomly allocated in a split-mouth design to a treatment group: (1) scaling and root planing (SRP group); (2) SRP and irrigation with toluidine blue O (TBO group); and (3) SRP, irrigation with TBO and low-level laser irradiation (PDT group). Clinical parameters including visible plaque index, bleeding gingival index, bleeding on probing, probing depth, gingival recession and clinical attachment level were measured at baseline, and after 60, 90 and 180 days. Additionally, subgingival plaque samples were collected for microbiological analysis by PCR. Intergroup and intragroup statistical analyses were performed. All treatment groups showed an improvement in all clinical parameters, and a significant reduction in the proportion of sites positive for periodontopathogens at 60, 90 and 180 days compared to baseline (p < 0.05). None of the periodontal parameters showed a significant difference among the groups (p > 0.05). At 180 days, PDT treatment led to a significant reduction in the percentage of sites positive for all bacteria compared to SRP alone (p < 0.05). Within the limits of this study it may be concluded that PDT as an adjunct to periodontal treatment produced statistically significant reductions in some of the key periodontal pathogens but produced no statistically significant benefit in terms of clinical outcome.

Research paper thumbnail of Periodontal Tissue Response to Coverage of Root Cavities Restored With Resin Materials: A Histomorphometric Study in Dogs

Journal of Periodontology, 2007

Background: The purpose of this study was to histomorphometrically evaluate the response of perio... more Background: The purpose of this study was to histomorphometrically evaluate the response of periodontal tissues covering Class V resin restorations in dogs.

Research paper thumbnail of Effect of Er:YAG and Diode lasers on the adhesion of blood components and on the morphology of irradiated root surfaces

Journal of Periodontal Research, 2006

Objective: The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM)... more Objective: The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM), the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94 µm) and GaAlAs Diode (808 nm) lasers and the effects on the morphology of irradiated root surfaces.Methods: One hundred samples of human teeth were obtained. They were previously planed and scaled with manual instruments and divided into five groups of 20 samples each: G1 (control group) – absence of treatment; G2 – Er:YAG laser (7.6 J/cm2); G3 – Er:YAG laser (12.9 J/cm2); G4 – Diode laser (90 J/cm2) and G5 – Diode laser (108 J/cm2). After these treatments, 10 samples of each group received a blood tissue but the remaining 10 did not. After laboratory treatments, the samples were obtained by SEM, the photomicrographs were analysed by the score of adhesion of blood components and the results were statistically analysed (Kruskall–Wallis and Mann–Whitney test).Results: In relation to the adhesion of blood components, the study showed no significant differences between the control group and the groups treated with Er:YAG laser (p = 0.9633 and 0.6229). Diode laser radiation was less effective than control group and Er:YAG laser radiation (p < 0.01).Conclusions: None of the proposed treatments increased the adhesion of blood components in a significant way when compared to the control group. Although the Er:YAG laser did not interfere in the adhesion of blood components, it caused more changes on the root surface, whereas the Diode laser inhibited the adhesion.

Research paper thumbnail of Influence of the proportion of particulate autogenous bone graft/platelet-rich plasma on bone healing in critical-size defects

Bone, 2009

This immunohistochemical analysis evaluated the influence of the proportion of particulate autoge... more This immunohistochemical analysis evaluated the influence of the proportion of particulate autogenous bone (AB) graft/platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in rat calvaria. 25 rats were divided into 5 groups: C (control), AB, AB/PRP-50, AB/PRP-100 and AB/PRP-150. A 5 mm diameter critical-size defect was created in the calvarium of each animal. In Group C, defect was filled by blood clot only. In Group AB, defect was filled with AB graft. In Groups AB/PRP-50, AB/PRP-100 and AB/ PRP-150, defects were filled with AB graft combined with 50, 100 and 150 μl of PRP, respectively. Animals were euthanized at 30 days post-operative. Osteocalcin (OC) and osteopontin (OP) immunohistochemical staining were performed. OP-positive and OC-positive cells were quantified. The amount of vital bone (VBA) and remaining bone graft particles (RPA) were calculated as percentage of the total area of the original defect. Data were statistically analyzed (ANOVA, Tukey, p b 0.05). Group AB/PRP-100 presented a significantly higher number of OP-positive cells than groups C, AB/PRP-50 and AB/PRP-150 (p b 0.05) and also a significantly higher number of OC-positive cells than all of the other groups (p b 0.05). The number of OP-positive cells in Group AB/PRP-150 was significantly lower than in Group AB (p b 0.05). Statistically significant differences were not found between groups with regard to either VBA or RPA (p N 0.05). However, clear trends were indicated by an increase in VBA in Group AB/PRP-100 when compared to groups C, AB and AB/PRP-150 and an increase in RPA in Group AB/PRP-150 when compared to groups AB, AB/PRP-50 and AB/PRP-100. The proportion AB graft/PRP seems to influence bone healing in CSD in rat calvaria. The highest expression of osteocalcin and osteopontin, and thus the most developed healing, was found in Group AB/PRP-100 indicating that there may be an optimal proportion beyond which increasing the concentration PRP is deleterious.

Research paper thumbnail of Comparison between laser therapy and non-surgical therapy for periodontitis in rats treated with dexamethasone

Lasers in Medical Science, 2010

The aim of this study was to compare low-level laser therapy (LLLT) as adjuvant treatment for ind... more The aim of this study was to compare low-level laser therapy (LLLT) as adjuvant treatment for induced periodontitis with scaling and root planing (SRP) in dexamethasone-treated rats. One-hundred twenty rats were divided into groups: D group (n = 60), treated with dexamethasone; ND group (n = 60) treated with saline solution. In both groups, periodontal disease was induced by ligature at the left first mandibular molar. After 7 days, the ligature was removed and all animals were subjected to SRP and were divided according to the following treatments: SRP, irrigation with saline solution (SS); SRP + LLLT, SS and laser irradiation (660 nm; 24 J; 0.428 W/cm2). Ten animals in each treatment were killed after 7 days, 15 days and 30 days. The radiographic and histometric values were statistically analyzed. In all groups radiographic and histometric analysis showed less bone loss (P < 0.05) in animals treated with SRP + LLLT in all experimental periods. SRP + LLLT was an effective adjuvant conventional treatment for periodontitis in rats treated with dexamethasone.

Research paper thumbnail of Effects of a single near-infrared laser treatment on cutaneous wound healing: Biometrical and histological study in rats

Journal of Photochemistry and Photobiology B-biology, 2007

Background: Low intensity laser therapy has been recommended to support the cutaneous repair; how... more Background: Low intensity laser therapy has been recommended to support the cutaneous repair; however, so far studies do not have evaluated the tissue response following a single laser treatment. This study investigated the effect of a single laser irradiation on the healing of full-thickness skin lesions in rats. Methods: Forty-eight male rats were randomly divided into three groups. One surgical lesion was created on the back of rats using a punch of 8 mm in diameter. One group was not submitted to any treatment after surgery and it was used as control. Two energy doses from an 830-nm near-infrared diode laser were used immediately post-wounding: 1.3 J cm À2 and 3 J cm À2 . The laser intensity 53 mW cm À2 was kept for both groups. Biometrical and histological analyses were accomplished at days 3, 7 and 14 post-wounding. Results: Irradiated lesions presented a more advanced healing process than control group. The dose of 1.3 J cm À2 leaded to better results. Lesions of the group irradiated with 1.3 J cm À2 presented faster lesion contraction showing quicker re-epithelization and reformed connective tissue with more organized collagen fibers. Conclusions: Low-intensity laser therapy may accelerate cutaneous wound healing in a rat model even if a single laser treatment is performed. This finding might broaden current treatment regimens.

Research paper thumbnail of A Histologic Assessment of the Influence of Low-Intensity Laser Therapy on Wound Healing in Steroid-Treated Animals

Photomedicine and Laser Surgery, 2004

The aim of the present study was to evaluate the effect of low-intensity laser therapy on the wou... more The aim of the present study was to evaluate the effect of low-intensity laser therapy on the wound healing process treated with steroid. Various biological effects have been associated with low-level laser therapy (LLLT). Forty-eight rats were used, and after execution of a wound on the dorsal region of each animal, they were divided into 4 groups (n = 12), receiving the following treatments: G1 (control), wounds and animals received no treatment; G2, wounds were treated with LLLT; G3, animals received an intraperitoneal injection of steroid dosage (2 mg/kg of body weight); G4, animals received steroid and wounds were treated with LLLT. The laser emission device used was a GaAIAs (904 nm), in a contact mode, with 2.75 mW gated with 2.900 Hz during 120 sec (33 J/cm(2)). After the period of 3, 7, and 14 days, the animals were sacrificed and the parts sent to histological processing and dyed using hematoxylin and eosin (HE) and Masson trichromium (MT) techniques. The results have shown that the wounds treated with steroid had a delay in healing, while LLLT accelerated the wound healing process. Also, wounds treated with laser in the animals treated with steroid presented a differentiated healing process with a larger collagen deposition and also a decrease in both the inflammatory infiltrated and the delay on the wound healing process. LLLT accelerated healing, caused by the steroid, acting as a biostimulative coadjutant agent, balancing the undesirable effects of cortisone on the tissue healing process.

Research paper thumbnail of Histometric analysis of ligature-induced periodontitis in rats: a comparison of histological section planes

Journal of Applied Oral Science, 2008

The purpose of this study was to analyze the histometry of ligature-induced periodontitis in rats... more The purpose of this study was to analyze the histometry of ligature-induced periodontitis in rats at different histological section depths. Sixteen male adult Wistar rats were randomly assigned to two groups: ligature and control. In the ligature group, rats received a sterile 4/0 silk ligature around the maxillary right 2nd molar. Thirty serial sections containing the 1st and 2nd molars, in which the coronal and root pulp, cementoenamel junction (CEJ) in the mesial side of the 2nd molar, interproximal alveolar bone and connective fiber attachment were clearly visible, were selected for histometric analysis. The histological sections were clustered in groups of 10 sections corresponding the buccal (B), central (C) and lingual (L) regions of the of periodontal tissue samples. The distance between the CEJ in the mesial side of the 2nd molar and the attached periodontal ligament fibers (CEJ-PL) as well as the distance between the CEJ and the alveolar bone crest (CEJ-BC) were determined. From CEJ-PL and CEJ-BC distances measured for each specimen, the measurements obtained in the B, L and C regions were recorded individually and together. Data were submitted to statistical analysis. Significant differences (p<0.001) were observed between the control and ligature groups regarding CEJ-PL (0.05 mm and 0.26 mm, respectively) and CEJ-BC (0.47 mm and 0.77 mm, respectively) measurements. Regarding the depth of the buccal, central and lingual planes, the means of CEJ-PL and CEJ-BC of both groups showed no statistically significant differences (p>0.05). In conclusion, the selection of 10 serial sections of the central region of periodontal tissue samples at any depth can be considered as representative for the evaluation of periodontal ligament fiber attachment and bone loss in ligature-induced periodontitis in rats.

Research paper thumbnail of Influence of low-level laser therapy on wound healing in nicotine-treated animals

Lasers in Medical Science

Low-level laser therapy (LLLT) has been shown to have several biological effects that favor the h... more Low-level laser therapy (LLLT) has been shown to have several biological effects that favor the healing process, and nicotine has been shown to delay the healing process. In this study we investigated the healing of open wounds created on the back of rats treated with nicotine with or without LLLT. Of 115 animals, 59 received subcutaneous injections of saline solution, and the others received subcutaneous injections of nicotine (3 mg/kg body weight), twice a day throughout the study period. After 30 days, skin wounds were created on the back of the animals. The animals receiving saline injections were divided into two groups: group 1 (G1, n = 29), in which the wounds were left untreated, and group 2 (G2, n = 30), in which the wounds were treated with LLLT (GaAlAs, 660 nm, 30 mW, 5.57 J/cm2 per point, 0.39 J, 13 s per point, 0.42 W/cm2). The animals receiving nicotine injections were also divided into two groups: group 3 (G3, n = 29), in which the wounds were left untreated, and group 4 (G4, n = 27), in which the wounds were treated with LLLT. The animals were killed 3, 7 or 14 days after surgery. Wound healing was evaluated histologically both qualitatively and semiquantitatively. Wounds of G2 showed a delay in epithelial migration and connective tissue organization compared to those of G1. Wounds of G2 showed faster healing than those of G1; similarly, wounds of G4 showed more advanced healing than those of G3. LLLT acted as a biostimulatory coadjuvant agent balancing the undesirable effects of nicotine on wound tissue healing.

Research paper thumbnail of Effect of photodynamic therapy on the healing of cutaneous third-degree-burn: histological study in rats

Lasers in Medical Science, 2010

The aim of this study was to conduct a histological assessment of the effect of photodynamic ther... more The aim of this study was to conduct a histological assessment of the effect of photodynamic therapy (PDT) on the repairing of third-degree-burn wounds made on the backs of rats with a heated scalpel. Ninety-six rats were divided into groups: G1, control (n = 24), cold scalpel; G2, burned, heated scalpel (n = 24); G3, low-level laser therapy (LLLT) (n = 24), on burns; and G4, photodynamic therapy (PDT) (n = 24), toluidine-O blue (100 µg/ml) and LLLT treatment on burns. The laser (685 nm) was applied in continuous mode, 50 mW, 4.5 J/cm2, contact mode at nine points (9 s/point). Eight animals in each group were killed at 3 days, 7 days or 14 days after surgery, and tissue specimens containing the whole wounded area were removed and processed for histological analysis; the results were statistically analyzed with Kruskal–Wallis and Dunn’s tests (P < 0.05). The results demonstrated significant differences between G2 and G3, and between G2 and G4, at both 3 days and 7 days, with regard to acute inflammation scores; G1 and G2 showed significant differences when compared with G4 at 3 days, with regard to neo-angiogenesis scores; G1 and G2 were statistically different from G3 and G4 at both 3 days and 7 days, with regard to re-epithelization scores; G2 showed statistically significant differences when compared with G3 and G4 with regard to collagen fiber scores at 7 days. LLLT and PDT acted as a biostimulating coadjuvant agent, balancing the undesirable effect of the burn on the wound healing process, acting mainly in the early healing stages, hastening inflammation and increasing collagen deposition.

Research paper thumbnail of Periodontal Plastic Surgery Associated With Treatment for the Removal of Gingival Overgrowth

Journal of Periodontology, 2006

Excisional biopsies of gingival overgrowths, performed with safety margins, frequently result in ... more Excisional biopsies of gingival overgrowths, performed with safety margins, frequently result in mucogingival defects. These defects may produce esthetic problems and increase the chances of dentin hyperesthesia and its possibility of hindering oral hygiene. Two clinical cases are reported in which gingival overgrowths were removed by excisional biopsy, resulting in unsightly defects. The first clinical case presents an invasive approach for the treatment of a recurrent pyogenic granuloma in the anterior maxilla, and the second depicts a complete removal of a peripheral odontogenic fibroma in the posterior maxilla. In both situations, the soft-tissue defects were repaired by periodontal plastic surgery, including a laterally positioned flap and a coronally positioned flap, respectively. Periodontal plastic surgery successfully restored the defects that resulted from biopsies, and no recurrence has been noticed in the 5-year postoperative follow-up period. The combination of biopsy and periodontal plastic surgery in a one-step procedure seems to be suitable to remove gingival overgrowths in most areas of the mouth, regardless of esthetic significance. Such procedures seem to restore gingival health, encourage healing, and create both esthetics and function in the excised area.

Research paper thumbnail of Treatment of Experimental Periodontal Disease by Photodynamic Therapy in Rats With Diabetes

Journal of Periodontology, 2008

Research paper thumbnail of A Histologic and Histometric Assessment of the Influence of Nicotine on Alveolar Bone Loss in Rats

Journal of Periodontology, 2007

Background: Cigarette smoking has long been recognized as a risk factor for periodontal disease. ... more Background: Cigarette smoking has long been recognized as a risk factor for periodontal disease. The aim of this study was to perform quantitative and qualitative analyses of bone loss in the furcation region of periodontally healthy rats after daily systemic administration of nicotine or saline solution.

Research paper thumbnail of Influence of Photodynamic Therapy on the Development of Ligature-Induced Periodontitis in Rats

Journal of Periodontology, 2007

Research paper thumbnail of Morphologic analysis, by means of scanning electron microscopy, of the effect of Er: YAG laser on root surfaces submitted to scaling and root planing

The pur po se of this study was to morp ho lo gi cally eva lu a te, by me ans of scan ning elec t... more The pur po se of this study was to morp ho lo gi cally eva lu a te, by me ans of scan ning elec tron mi cros copy, the ef fects of Er:YAG la ser on the tre at ment of root sur fa ces sub mit ted to sca ling and root pla ning with con ven ti o nal pe ri odon tal ins tru ments. Eigh te en root sur fa ces (n = 18), which had been pre vi ously sca led and pla ned, were as sig ned to 3 groups (n = 6). The con trol Group (G1) re ce i ved no furt her tre at ment; Group 2 (G2) was ir ra di a ted with Er:YAG la ser (2.94 µm), with 47 mJ/10 Hz, in a fo cu sed mode with air/wa ter spray du ring 15 s and with 0.57 J/cm 2 of flu ency per pul se; Group 3 (G 3) was ir ra di a ted with Er:YAG la ser (2.94 µm), with 83 mJ/10 Hz, in a fo cu sed mode with air/wa ter spray du ring 15 s and with 1.03 J/cm 2 of flu ency per pul se. We con clu ded that the pa ra me ters adop ted for Group 3 remo ved the sme ar la yer from the root sur fa ce, ex po sing the den ti nal tu bu les. Although no fis su res, cracks or car bo nized are as were ob ser ved, an ir re gu lar sur fa ce was pro du ced by Er:YAG la ser ir ra di a ti on. Thus, the bi o com pa ti bi lity of the ir ra di a ted root sur fa ce, wit hin the pe ri o don tal he a ling pro cess, must be as ses s ed.

Research paper thumbnail of Effect of platelet-rich plasma on bone healing of autogenous bone grafts in critical-size defects

Journal of Clinical Periodontology, 2009

Aim: This study histologically analysed the effect of autogenous platelet-rich plasma (PRP), prep... more Aim: This study histologically analysed the effect of autogenous platelet-rich plasma (PRP), prepared according to a new semiautomatic system, on healing of autogenous bone (AB) grafts placed in surgically created critical-size defects (CSD) in rabbit calvaria.Material and Methods: Sixty rabbits were divided into three groups: C, AB and AB/PRP. A CSD was created in the calvarium of each animal. In Group C (control), the defect was filled by blood clot only. In Group AB (autogenous bone graft), the defect was filled with particulate autogenous bone. In Group AB/PRP (autogenous bone graft with platelet-rich plasma), it was filled with particulate autogenous bone combined with PRP. All groups were divided into subgroups (n=10) and euthanized at 4 or 12 weeks post-operatively. Histometric and histologic analyses were performed. Data were statistically analysed (anova, t-test, p<0.05).Results: Group C presented significantly less bone formation compared with Group AB and AB/PRP in both periods of analysis (p<0.001). At 4 weeks, Group AB/PRP showed a statistically greater amount of bone formation than Group AB (64.44 ± 15.0%versus 46.88 ± 14.15%; p=0.0181). At 12 weeks, no statistically significant differences were observed between Groups AB and AB/PRP (75.0 ± 8.11%versus 77.90 ± 8.13%; p>0.05). It is notable that the amount of new bone formation in Group AB/PRP at 4 weeks was similar to that of Group AB at 12 weeks (p>0.05).Conclusion: Within its limitation, the present study has indicated that (i) AB and AB/PRP significantly improved bone formation and (ii) a beneficial effect of PRP was limited to an initial healing period of 4 weeks.

Research paper thumbnail of Treatment of Ligature-Induced Peri-Implantitis by Lethal Photosensitization and Guided Bone Regeneration: A Preliminary Histologic Study in Dogs

Journal of Periodontology, 2003

This study evaluated the treatment of ligature-induced peri-implantitis using guided tissue regen... more This study evaluated the treatment of ligature-induced peri-implantitis using guided tissue regeneration (GTR) around submerged and nonsubmerged implants in beagle dogs. Two titanium implants were placed bilaterally in the premolar regions of the mandible in each of 10 beagle dogs. Cotton floss ligatures were placed around the implant necks and no oral hygiene procedures were performed for 5 months. Periodontal surgery was performed, and in five dogs (submerged group) the abutments were removed and an e-PTFE barrier was placed to cover the test implants and their adjacent osseous defects, while the control implants received no barriers. In the other five dogs (nonsubmerged group), flap surgery was performed without removing the abutments. In the test sites, an e-PTFE barrier was placed around the abutment and adjacent defects, while on the control sites no barrier was placed. Nondecalcified specimens were prepared using standard histologic methods and analyzed. No differences were found between any of the clinical parameters in both the control and experimental sites from the submerged and nonsubmerged groups. Histologic and histomorphometric analyses also revealed no significant differences between groups with regard to new bone formation. In the experimental (GTR) groups, however, the amount of regenerated connective tissue was significantly greater than on the control groups. Under the conditions of this study, the treatment of peri-implantitis using GTR did not enhance clinical parameters or bone formation around "diseased" implants. (I NT J ORAL MAXILLOFAC IMPLANTS 1993;8 282-293.)

Research paper thumbnail of Treatment of experimental periodontal disease by photodynamic therapy in immunosuppressed rats

Journal of Clinical Periodontology, 2009

Background and Objective: The aim of this study was to compare photodynamic therapy (PDT) as an a... more Background and Objective: The aim of this study was to compare photodynamic therapy (PDT) as an adjunctive treatment of induced periodontitis with scaling and root planing (SRP) in dexamethasone-inhibited rats.Material and Methods: The animals were divided into two groups: ND (n=90), saline solution treatment; D (n=90), dexamethasone treatment. In the ND and D Groups, periodontal disease was ligature-induced at the first mandibular molar. After 7 days, the ligature was removed and all animals received SRP and were divided according to the following treatments: SRP, saline solution; Toluidine Blue-O (TBO), phenothiazinium dye; and PDT, TBO and laser irradiation. Ten animals in each treatment were killed at 7, 15 and 30 days. The radiographic and histometric values were statistically analysed.Results: In the ND and D Groups, radiographic analysis showed less bone loss in animals treated by PDT in all the experimental periods than SRP and TBO at 15 days (p<0.05). After a histometric analysis was carried out in the ND and D groups, the animals treated by PDT showed less bone loss in all periods than SRP and TBO after 15 days (p<0.05).Conclusions: The PDT was an effective adjunctive treatment of induced periodontitis compared with SRP in dexamethasone-inhibited rats.

Research paper thumbnail of Comparative analysis of root surface smear layer removal by different etching modalities or erbium:yttrium–aluminum–garnet laser irradiation. A scanning electron microscopy study

Lasers in Medical Science, 2010

The purpose of this study was to evaluate the effect of erbium:yttrium–aluminum–garnet (Er:YAG) l... more The purpose of this study was to evaluate the effect of erbium:yttrium–aluminum–garnet (Er:YAG) laser (2.94 μm) irradiation on the removal of root surface smear layer of extracted human teeth and to compare its efficacy with that of citric acid, ethylenediamine tetra-acetic acid (EDTA), or a gel containing a mixture of tetracycline hydrochloride (HCl) and citric acid, using scanning electron microscopy (SEM). Thirty human dentin specimens were randomly divided into six groups: G1 (control group), irrigated with 10 ml of physiologic saline solution; G2, conditioned with 24% citric acid gel; G3, conditioned with 24% EDTA gel; G4, conditioned with a 50% citric acid and tetracycline gel; G5, irradiated with Er:YAG laser (47 mJ/10 Hz/5.8 J/cm2/pulse); G6, irradiated with Er:YAG laser (83 mJ/10 Hz/10.3 J/cm2/pulse). Electron micrographs were obtained and analyzed according to a rating system. Statistical analysis was conducted with Kruskal–Wallis and Mann–Whitney tests (P < 0.05). G1 was statistically different from all the other groups; no statistically significant differences were observed between the Er:YAG laser groups and those undergoing the other treatment modalities. When the two Er:YAG laser groups were compared, the fluency of G6 was statistically more effective in smear layer removal than the one used in G5 (Mann–Whitney test, P < 0.01). Root surfaces irradiated by Er:YAG laser had more irregular contours than those treated by chemical agents. It can be concluded that all treatment modalities were effective in smear layer removal. The results of our study suggest that the Er:YAG laser can be safely used to condition diseased root surfaces effectively. Furthermore, the effect of Er:YAG laser irradiation on root surfaces should be evaluated in vivo so that its potential to enhance the healing of periodontal tissues can be assessed.

Research paper thumbnail of In Vivo Effect of Photodynamic Therapy on Periodontal Bone Loss in Dental Furcations

Journal of Periodontology, 2008

The purpose of this study was to histometrically evaluate the influence of photodynamic therapy o... more The purpose of this study was to histometrically evaluate the influence of photodynamic therapy on bone loss in furcation areas in rats with experimentally induced periodontal disease. Ligatures were placed on the first mandibular molar in rats. Then the animals were divided into four groups: control group = no treatment; methylene blue group (MB) = treated topically with methylene blue (100 microg/ml); laser group (LLLT) = treated with low-level laser therapy; and photodynamic therapy group (PDT) = treated topically with MB followed by LLLT (4.5 J/cm(2)). Rats from all groups were sacrificed at 7, 15, or 30 days postoperatively. The area of bone loss in the furcation region of the first molar was histometrically analyzed. Data were analyzed statistically (analysis of variance and Bonferroni tests; P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt;0.05). The PDT group demonstrated less bone loss compared to the other groups at 7 days (1.986 +/- 0.417 mm(2)); at 15 days, the PDT (1.641 +/- 0.115 mm(2)) and MB groups (1.991 +/- 0.294 mm(2)) demonstrated less bone loss compared to the control (4.062 +/- 0.416 mm(2)) and LLLT (2.641 +/- 0.849 mm(2)) groups. Within the parameters used in this study, PDT may be an effective alternative for control of bone loss in furcation areas in periodontitis.

Research paper thumbnail of Clinical and microbiological effects of photodynamic therapy associated with nonsurgical periodontal treatment. A 6-month follow-up

Lasers in Medical Science

Experimental studies in animals and in vitro have shown the usefulness of photodynamic therapy (P... more Experimental studies in animals and in vitro have shown the usefulness of photodynamic therapy (PDT) as an adjunct to periodontal treatment. The aim of this study was to evaluate the long-term clinical and microbiological effects of PDT associated with nonsurgical periodontal treatment. Three sites in each of 33 patients with chronic periodontitis were randomly allocated in a split-mouth design to a treatment group: (1) scaling and root planing (SRP group); (2) SRP and irrigation with toluidine blue O (TBO group); and (3) SRP, irrigation with TBO and low-level laser irradiation (PDT group). Clinical parameters including visible plaque index, bleeding gingival index, bleeding on probing, probing depth, gingival recession and clinical attachment level were measured at baseline, and after 60, 90 and 180 days. Additionally, subgingival plaque samples were collected for microbiological analysis by PCR. Intergroup and intragroup statistical analyses were performed. All treatment groups showed an improvement in all clinical parameters, and a significant reduction in the proportion of sites positive for periodontopathogens at 60, 90 and 180 days compared to baseline (p < 0.05). None of the periodontal parameters showed a significant difference among the groups (p > 0.05). At 180 days, PDT treatment led to a significant reduction in the percentage of sites positive for all bacteria compared to SRP alone (p < 0.05). Within the limits of this study it may be concluded that PDT as an adjunct to periodontal treatment produced statistically significant reductions in some of the key periodontal pathogens but produced no statistically significant benefit in terms of clinical outcome.

Research paper thumbnail of Periodontal Tissue Response to Coverage of Root Cavities Restored With Resin Materials: A Histomorphometric Study in Dogs

Journal of Periodontology, 2007

Background: The purpose of this study was to histomorphometrically evaluate the response of perio... more Background: The purpose of this study was to histomorphometrically evaluate the response of periodontal tissues covering Class V resin restorations in dogs.

Research paper thumbnail of Effect of Er:YAG and Diode lasers on the adhesion of blood components and on the morphology of irradiated root surfaces

Journal of Periodontal Research, 2006

Objective: The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM)... more Objective: The aim of this study was to evaluate in vitro, by scanning electron microscopy (SEM), the adhesion of blood components on root surfaces irradiated with Er:YAG (2.94 µm) and GaAlAs Diode (808 nm) lasers and the effects on the morphology of irradiated root surfaces.Methods: One hundred samples of human teeth were obtained. They were previously planed and scaled with manual instruments and divided into five groups of 20 samples each: G1 (control group) – absence of treatment; G2 – Er:YAG laser (7.6 J/cm2); G3 – Er:YAG laser (12.9 J/cm2); G4 – Diode laser (90 J/cm2) and G5 – Diode laser (108 J/cm2). After these treatments, 10 samples of each group received a blood tissue but the remaining 10 did not. After laboratory treatments, the samples were obtained by SEM, the photomicrographs were analysed by the score of adhesion of blood components and the results were statistically analysed (Kruskall–Wallis and Mann–Whitney test).Results: In relation to the adhesion of blood components, the study showed no significant differences between the control group and the groups treated with Er:YAG laser (p = 0.9633 and 0.6229). Diode laser radiation was less effective than control group and Er:YAG laser radiation (p < 0.01).Conclusions: None of the proposed treatments increased the adhesion of blood components in a significant way when compared to the control group. Although the Er:YAG laser did not interfere in the adhesion of blood components, it caused more changes on the root surface, whereas the Diode laser inhibited the adhesion.

Research paper thumbnail of Influence of the proportion of particulate autogenous bone graft/platelet-rich plasma on bone healing in critical-size defects

Bone, 2009

This immunohistochemical analysis evaluated the influence of the proportion of particulate autoge... more This immunohistochemical analysis evaluated the influence of the proportion of particulate autogenous bone (AB) graft/platelet-rich plasma (PRP) on bone healing in surgically created critical-size defects (CSD) in rat calvaria. 25 rats were divided into 5 groups: C (control), AB, AB/PRP-50, AB/PRP-100 and AB/PRP-150. A 5 mm diameter critical-size defect was created in the calvarium of each animal. In Group C, defect was filled by blood clot only. In Group AB, defect was filled with AB graft. In Groups AB/PRP-50, AB/PRP-100 and AB/ PRP-150, defects were filled with AB graft combined with 50, 100 and 150 μl of PRP, respectively. Animals were euthanized at 30 days post-operative. Osteocalcin (OC) and osteopontin (OP) immunohistochemical staining were performed. OP-positive and OC-positive cells were quantified. The amount of vital bone (VBA) and remaining bone graft particles (RPA) were calculated as percentage of the total area of the original defect. Data were statistically analyzed (ANOVA, Tukey, p b 0.05). Group AB/PRP-100 presented a significantly higher number of OP-positive cells than groups C, AB/PRP-50 and AB/PRP-150 (p b 0.05) and also a significantly higher number of OC-positive cells than all of the other groups (p b 0.05). The number of OP-positive cells in Group AB/PRP-150 was significantly lower than in Group AB (p b 0.05). Statistically significant differences were not found between groups with regard to either VBA or RPA (p N 0.05). However, clear trends were indicated by an increase in VBA in Group AB/PRP-100 when compared to groups C, AB and AB/PRP-150 and an increase in RPA in Group AB/PRP-150 when compared to groups AB, AB/PRP-50 and AB/PRP-100. The proportion AB graft/PRP seems to influence bone healing in CSD in rat calvaria. The highest expression of osteocalcin and osteopontin, and thus the most developed healing, was found in Group AB/PRP-100 indicating that there may be an optimal proportion beyond which increasing the concentration PRP is deleterious.

Research paper thumbnail of Comparison between laser therapy and non-surgical therapy for periodontitis in rats treated with dexamethasone

Lasers in Medical Science, 2010

The aim of this study was to compare low-level laser therapy (LLLT) as adjuvant treatment for ind... more The aim of this study was to compare low-level laser therapy (LLLT) as adjuvant treatment for induced periodontitis with scaling and root planing (SRP) in dexamethasone-treated rats. One-hundred twenty rats were divided into groups: D group (n = 60), treated with dexamethasone; ND group (n = 60) treated with saline solution. In both groups, periodontal disease was induced by ligature at the left first mandibular molar. After 7 days, the ligature was removed and all animals were subjected to SRP and were divided according to the following treatments: SRP, irrigation with saline solution (SS); SRP + LLLT, SS and laser irradiation (660 nm; 24 J; 0.428 W/cm2). Ten animals in each treatment were killed after 7 days, 15 days and 30 days. The radiographic and histometric values were statistically analyzed. In all groups radiographic and histometric analysis showed less bone loss (P < 0.05) in animals treated with SRP + LLLT in all experimental periods. SRP + LLLT was an effective adjuvant conventional treatment for periodontitis in rats treated with dexamethasone.

Research paper thumbnail of Effects of a single near-infrared laser treatment on cutaneous wound healing: Biometrical and histological study in rats

Journal of Photochemistry and Photobiology B-biology, 2007

Background: Low intensity laser therapy has been recommended to support the cutaneous repair; how... more Background: Low intensity laser therapy has been recommended to support the cutaneous repair; however, so far studies do not have evaluated the tissue response following a single laser treatment. This study investigated the effect of a single laser irradiation on the healing of full-thickness skin lesions in rats. Methods: Forty-eight male rats were randomly divided into three groups. One surgical lesion was created on the back of rats using a punch of 8 mm in diameter. One group was not submitted to any treatment after surgery and it was used as control. Two energy doses from an 830-nm near-infrared diode laser were used immediately post-wounding: 1.3 J cm À2 and 3 J cm À2 . The laser intensity 53 mW cm À2 was kept for both groups. Biometrical and histological analyses were accomplished at days 3, 7 and 14 post-wounding. Results: Irradiated lesions presented a more advanced healing process than control group. The dose of 1.3 J cm À2 leaded to better results. Lesions of the group irradiated with 1.3 J cm À2 presented faster lesion contraction showing quicker re-epithelization and reformed connective tissue with more organized collagen fibers. Conclusions: Low-intensity laser therapy may accelerate cutaneous wound healing in a rat model even if a single laser treatment is performed. This finding might broaden current treatment regimens.

Research paper thumbnail of A Histologic Assessment of the Influence of Low-Intensity Laser Therapy on Wound Healing in Steroid-Treated Animals

Photomedicine and Laser Surgery, 2004

The aim of the present study was to evaluate the effect of low-intensity laser therapy on the wou... more The aim of the present study was to evaluate the effect of low-intensity laser therapy on the wound healing process treated with steroid. Various biological effects have been associated with low-level laser therapy (LLLT). Forty-eight rats were used, and after execution of a wound on the dorsal region of each animal, they were divided into 4 groups (n = 12), receiving the following treatments: G1 (control), wounds and animals received no treatment; G2, wounds were treated with LLLT; G3, animals received an intraperitoneal injection of steroid dosage (2 mg/kg of body weight); G4, animals received steroid and wounds were treated with LLLT. The laser emission device used was a GaAIAs (904 nm), in a contact mode, with 2.75 mW gated with 2.900 Hz during 120 sec (33 J/cm(2)). After the period of 3, 7, and 14 days, the animals were sacrificed and the parts sent to histological processing and dyed using hematoxylin and eosin (HE) and Masson trichromium (MT) techniques. The results have shown that the wounds treated with steroid had a delay in healing, while LLLT accelerated the wound healing process. Also, wounds treated with laser in the animals treated with steroid presented a differentiated healing process with a larger collagen deposition and also a decrease in both the inflammatory infiltrated and the delay on the wound healing process. LLLT accelerated healing, caused by the steroid, acting as a biostimulative coadjutant agent, balancing the undesirable effects of cortisone on the tissue healing process.

Research paper thumbnail of Histometric analysis of ligature-induced periodontitis in rats: a comparison of histological section planes

Journal of Applied Oral Science, 2008

The purpose of this study was to analyze the histometry of ligature-induced periodontitis in rats... more The purpose of this study was to analyze the histometry of ligature-induced periodontitis in rats at different histological section depths. Sixteen male adult Wistar rats were randomly assigned to two groups: ligature and control. In the ligature group, rats received a sterile 4/0 silk ligature around the maxillary right 2nd molar. Thirty serial sections containing the 1st and 2nd molars, in which the coronal and root pulp, cementoenamel junction (CEJ) in the mesial side of the 2nd molar, interproximal alveolar bone and connective fiber attachment were clearly visible, were selected for histometric analysis. The histological sections were clustered in groups of 10 sections corresponding the buccal (B), central (C) and lingual (L) regions of the of periodontal tissue samples. The distance between the CEJ in the mesial side of the 2nd molar and the attached periodontal ligament fibers (CEJ-PL) as well as the distance between the CEJ and the alveolar bone crest (CEJ-BC) were determined. From CEJ-PL and CEJ-BC distances measured for each specimen, the measurements obtained in the B, L and C regions were recorded individually and together. Data were submitted to statistical analysis. Significant differences (p<0.001) were observed between the control and ligature groups regarding CEJ-PL (0.05 mm and 0.26 mm, respectively) and CEJ-BC (0.47 mm and 0.77 mm, respectively) measurements. Regarding the depth of the buccal, central and lingual planes, the means of CEJ-PL and CEJ-BC of both groups showed no statistically significant differences (p>0.05). In conclusion, the selection of 10 serial sections of the central region of periodontal tissue samples at any depth can be considered as representative for the evaluation of periodontal ligament fiber attachment and bone loss in ligature-induced periodontitis in rats.

Research paper thumbnail of Influence of low-level laser therapy on wound healing in nicotine-treated animals

Lasers in Medical Science

Low-level laser therapy (LLLT) has been shown to have several biological effects that favor the h... more Low-level laser therapy (LLLT) has been shown to have several biological effects that favor the healing process, and nicotine has been shown to delay the healing process. In this study we investigated the healing of open wounds created on the back of rats treated with nicotine with or without LLLT. Of 115 animals, 59 received subcutaneous injections of saline solution, and the others received subcutaneous injections of nicotine (3 mg/kg body weight), twice a day throughout the study period. After 30 days, skin wounds were created on the back of the animals. The animals receiving saline injections were divided into two groups: group 1 (G1, n = 29), in which the wounds were left untreated, and group 2 (G2, n = 30), in which the wounds were treated with LLLT (GaAlAs, 660 nm, 30 mW, 5.57 J/cm2 per point, 0.39 J, 13 s per point, 0.42 W/cm2). The animals receiving nicotine injections were also divided into two groups: group 3 (G3, n = 29), in which the wounds were left untreated, and group 4 (G4, n = 27), in which the wounds were treated with LLLT. The animals were killed 3, 7 or 14 days after surgery. Wound healing was evaluated histologically both qualitatively and semiquantitatively. Wounds of G2 showed a delay in epithelial migration and connective tissue organization compared to those of G1. Wounds of G2 showed faster healing than those of G1; similarly, wounds of G4 showed more advanced healing than those of G3. LLLT acted as a biostimulatory coadjuvant agent balancing the undesirable effects of nicotine on wound tissue healing.

Research paper thumbnail of Effect of photodynamic therapy on the healing of cutaneous third-degree-burn: histological study in rats

Lasers in Medical Science, 2010

The aim of this study was to conduct a histological assessment of the effect of photodynamic ther... more The aim of this study was to conduct a histological assessment of the effect of photodynamic therapy (PDT) on the repairing of third-degree-burn wounds made on the backs of rats with a heated scalpel. Ninety-six rats were divided into groups: G1, control (n = 24), cold scalpel; G2, burned, heated scalpel (n = 24); G3, low-level laser therapy (LLLT) (n = 24), on burns; and G4, photodynamic therapy (PDT) (n = 24), toluidine-O blue (100 µg/ml) and LLLT treatment on burns. The laser (685 nm) was applied in continuous mode, 50 mW, 4.5 J/cm2, contact mode at nine points (9 s/point). Eight animals in each group were killed at 3 days, 7 days or 14 days after surgery, and tissue specimens containing the whole wounded area were removed and processed for histological analysis; the results were statistically analyzed with Kruskal–Wallis and Dunn’s tests (P < 0.05). The results demonstrated significant differences between G2 and G3, and between G2 and G4, at both 3 days and 7 days, with regard to acute inflammation scores; G1 and G2 showed significant differences when compared with G4 at 3 days, with regard to neo-angiogenesis scores; G1 and G2 were statistically different from G3 and G4 at both 3 days and 7 days, with regard to re-epithelization scores; G2 showed statistically significant differences when compared with G3 and G4 with regard to collagen fiber scores at 7 days. LLLT and PDT acted as a biostimulating coadjuvant agent, balancing the undesirable effect of the burn on the wound healing process, acting mainly in the early healing stages, hastening inflammation and increasing collagen deposition.