Carla Gonzaga | Universidade Positivo (original) (raw)

Papers by Carla Gonzaga

Journal of Clinical and Experimental Dentistry, 2018

Background: Tooth bleaching is a popular aesthetic treatment to modify the color of teeth. Despit... more Background: Tooth bleaching is a popular aesthetic treatment to modify the color of teeth. Despite the extensive literature concerning the subject, there is still no consensus regarding the application mode of the different bleaching agents and their effect on enamel. Therefore, this study evaluated the influence of different bleaching protocols on whitening efficiency and enamel superficial hardness. Material and Methods: Bovine enamel fragments were embedded in acrylic resin and wet-sanded to obtain a flat buccal surface. The specimens were then randomly divided into 6 groups (n=10), based on the bleaching material [HP Maxx 35% (35% hydrogen peroxide), HP Blue 35% (35% hydrogen peroxide + Ca) and Whiteness Perfect 10% (10% carbamide peroxide)] and application mode (3 applications of 15 min, 1 application of 45 min, 1 application of 1h30 or 1 application of 3h30). The color and superficial hardness were assessed before and after bleaching. The color was assessed by means of a digital spectrophotometer, using CIELab parameters. Vickers hardness was determined using a load of 200g for 10s. Data were statistically analyzed by one-way ANOVA with repeated measures and Tukey's test (α = 0.05). Results: Concerning the color alteration, the groups were similar to each other, except for at-home bleaching protocols, which were statistically different from each other. Similarly, there was a reduction in hardness values comparing the initial and final periods, with lowest final hardness for the at-home bleaching protocol group applied for 3h30. Conclusions: It can be concluded that the bleaching protocols influenced the final color and enamel surface hardness, evidencing that lower gel concentrations applied for longer periods promoted greater variation in color and lower final hardness.

Oral and maxillofacial surgery, Jan 6, 2016

Bone graft is a very common procedure that is performed when bone volume needs to be increased be... more Bone graft is a very common procedure that is performed when bone volume needs to be increased before a dental implant. Screws and miniplates are the clinical standards for osteosynthesis. However, some disadvantages for this method have been reported, including artifacts on radiological images, infection, screw loosening, and the need to remove screws that interfere with the dental implants. Bone adhesives are a promising alternative for bone graft surgery. The aim of this study was to compare the shear bond strength of two cyanoacrylate-based adhesives and titanium screws for bone graft fixation. Pig jaw samples were cut into rectangular bars (2 × 6 × 20 mm) and bonded with a 5-mm overlap of N-butyl cyanoacrylate and ethyl cyanoacrylate, and 1.5-mm titanium screws were inserted into the center of the contact area. The blocks were fixed on a shear bond strength device that was coupled to a universal testing machine. The maximum force (N) was recorded on a computer and divided by th...

European Journal of Dentistry, Jul 1, 2010

Objectives:To verify the effect of interposing different indirect restorative materials on degree... more Objectives:To verify the effect of interposing different indirect restorative materials on degree of conversion (DC), hardness, and flexural strength of a dual-cure resin cement.Methods:Discs (2 mm-thick, n=5) of four indirect restorative materials were manufactured: a layered glass-ceramic (GC); a heat-pressed lithium disilicate-based glass-ceramic veneered with the layered glass-ceramic (LD); a micro-hybrid (MH); and a micro-filled (MF) indirect composite resin. The light transmittance of these materials was determined using a double-beam spectrophotometer with an integrating sphere. Bar-shaped specimens of a dual-cure resin cement (Nexus 2/SDS Kerr), with (dual-cure mode) and without the catalyst paste (light-cure mode), were photoactivated through the discs using either a quartz-tungsten-halogen (QTH) or a light-emitting diode (LED) unit. As a control, specimens were photoactivated without the interposed discs. Specimens were stored at 37ºC for 24h before being submitted to FT-Raman spectrometry (n=3), Knoop microhardness (n=6) and three-point bending (n=6) tests. Data were analyzed by ANOVA/Tukey’s test (α=0.05).Results:MH presented the highest transmittance. The DC was lower in light-cure mode than in dual-cure mode. All restorative materials reduced the cement microhardness in light-cure mode. GC and LD with QTH and GC with LED decreased the strength of the cement for both activation modes compared to the controls. Curing units did not affect DC or microhardness, except when the dual-cure cement was photoactivated through LD (LED>QTH). Flexural strength was higher with QTH compared to LED.Conclusions:Differences in transmittance among the restorative materials significantly influenced cement DC and flexural strength, regardless of the activation mode, as well as the microhardness of the resin cement tested in light-cure mode. Microhardness was not impaired by the interposed materials when the resin cement was used in dual-cure mode.

Odontologia Clinico Cientifica, Sep 1, 2011

International Scholarly Research Notices, 2015

ABSTRACT Objectives: To determine elastic modulus (E), Vickers hardness (H), fracture toughness (... more ABSTRACT Objectives: To determine elastic modulus (E), Vickers hardness (H), fracture toughness (KIc), and fracture surface energy (γf) of a vitreous porcelain (VM7/V), a leucite-based porcelain (d.Sign/D), a leucite-based glass-ceramic (Empress/E1), a lithium-disilicate glass-ceramic (Empress2/E2), and a glass-infiltrated alumina composite (In-Ceram Alumina/IC), and verify the correlation between these properties. Methods: Discs (n=10) were constructed according to manufacturers' instructions, ground to final dimensions (12mm in diameter and 1mm-thick), and polished. E and υ (Poisson's ratio) were determined by ultrasonic pulse-echo method. H was determined using 19.6N and dwell time of 20s. KIc was determined by indentation strength method, by introducing radial cracks with a Vickers indenter (load of 9.8N for porcelains, 19.6N for glass-ceramics and 49N for IC) at the center of the polished surface. Subsequently, the fracture stress was obtained in biaxial flexural test (0.5mm/min). Fracture surface energy values were calculated from the Griffith-Irwin relation for plane strain [KIc=√2Eγf/(1υ2)]. Data were statistically analyzed (ANOVA, Tukey's, p<0.05). Results: V, D and E1 showed similar E values, which were lower than the values obtained by E2 and IC. Regarding H, materials V, D and E1 showed similar values, which were significantly higher than that obtained by E2 and lower than that obtained by IC. IC and E2 showed the highest KIc values, followed by E1, D and V. Fracture surface energy values were higher for E2 and IC compared to other materials. Conclusion: Materials with higher elastic moduli showed higher fracture toughness, suggesting that these properties are positively correlated to each other. However, E didn't show relationship with H and γf. Acknowledgments: FAPESP/CNPQ/CAPES. E (GPa) υ H (GPa) KIc (MPa.m1/2) γf (J/m2) V 66.0c 0.215c 8.2b 0.67d 3.2 D 67.1c 0.217c 8.0b 0.84cd 5.0 E1 66.1c 0.210c 7.9b 0.96c 6.7 E2 99.3b 0.225b 5.8c 1.81b 15.7 IC 276.0a 0.239a 11.2a 2.91 14.5

Brazilian Dental Journal, 2015

The aim of this study was to evaluate the effect of silanization protocols on the bond strength o... more The aim of this study was to evaluate the effect of silanization protocols on the bond strength of two resin cements to a lithium disilicate glass-ceramic. Thirty-two ceramic discs were assigned to 2 groups (n=16): G1 - dual-cured resin cement and G2 - light-cured resin cement. Four subgroups were evaluated according to the used silanization protocol. The glass-ceramic was etched with 10% hydrofluoric acid for 20 s and silane was applied for 1 min, as follows: CTL - according to the manufacturer&amp;amp;amp;amp;amp;amp;amp;#39;s instructions; HA - dried with hot air; NWA - washed and dried with water and air at room temperature; HWA - washed and dried with hot water and hot air. Thereafter, adhesive was applied and light-cured for 20 s. Silicon molds were used to prepare resin cement cylinders (1x1 mm) on the ceramic surface. The specimens were stored in deionized water at 37 °C for 48 h and subjected to a micro-shear test. The data were submitted to statistical analysis (?#61537;=0.05). Group G1 showed higher bond strengths than G2, except for the CTL and NWA subgroups. Differences as function of the silanization protocol were only observed in G1: HWA (25.13±6.83)≥HA (22.95±7.78)≥CTL(17.44±7.24) ≥NWA(14.63±8.76). For G2 there was no difference among the subgroups. In conclusion, the silanization protocol affected the resin cement/ceramic bond strengths, depending on the material. Washing/drying with hot water and/or hot air increased only the bond strength of the dual-cured resin cement.

Rsbo Revista Sul Brasileira De Odontologia, 2012

Introduction: Dental diastemas are common findings at dental clinics. This clinical situation pro... more Introduction: Dental diastemas are common findings at dental clinics. This clinical situation produces discomfort in many patients and its solution is difficult to many professionals. Silicone guides, made from waxed casts, have been used to assist the stratification of resin composites in cases of dental diastemas. This technique, however, does not necessarily need to be used as protocol in all situations. Objective: To demonstrate the stratification technique without silicone guides. Case report:

American Journal of Dentistry, Aug 1, 2014

To evaluate the color parameters (CIELab*) after the cementation of ceramic disks of different th... more To evaluate the color parameters (CIELab*) after the cementation of ceramic disks of different thicknesses onto a resin substrate using four different shades of resin cements, and determine the color difference (ΔE) between the adhesively cemented disks and a 10 mm-thick A1 shade ceramic control (target color). Ceramic disks, simulating laminate veneers, with thicknesses of 0.5, 0.7 and 1.0 mm (shade A1, IPS Classic) were fabricated (n = 40) and cemented with a dual-cured resin cement (Variolink II, shades A1, bleach, opaque and transparent) onto 120 2 mm-thick resin composite substrates (shade A3.5, Adoro). Each ceramic disk was photocured for 80 seconds. The determination of the CIELab* parameters of each ceramic-cement-substrate set was performed with a spectrophotometer. A 10 mm-thick A1 ceramic disk was used as a control. The results for the color difference (ΔE) obtained from L*, a* and b* parameters were analyzed using ANOVA and Tukey&amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;#39;s test (α = 0.05). The ΔE values ranged from 2.46 (1.0 mm, opaque cement) to 12.11 (0.5 mm, A1 cement). The opaque cement showed the lower ΔE values, followed by the bleach, transparent and A1 cements. With respect to the thickness of the ceramic, color differences between the target color and the group with 1.0 mm ceramic disks were smaller for all cement shades tested. Only the combination of 1.0 mm ceramic disks cemented with the opaque cement was able to mask the background color (ΔE &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 3.7). The color differences between the control and the specimens cemented with opaque resin cement were smaller in comparison with the bleach, transparent and A1 cements.

Rsbo, Dec 1, 2010

... destilada. Primeiramente se efetuou a análise da determinação da cor após a segunda sessão de... more ... destilada. Primeiramente se efetuou a análise da determinação da cor após a segunda sessão de clareamento com auxílio de um espectrofotômetro digital (VITA Easyshade 3D Master, Vita Zahnfabrik, Bad Säckingen, Alemanha). ...

American journal of dentistry

ABSTRACT

$Research paper thumbnail of Rehabilitation of the dominance of maxillary central incisors with refractory porcelain veneers requiring minimal tooth preparation$

Quintessence international (Berlin, Germany : 1985), 2015

Central dominance is an important element of an esthetic smile. Color, form, and size have been s... more Central dominance is an important element of an esthetic smile. Color, form, and size have been suggested as tools for assessing the dominance of maxillary teeth. A spectrophotometer can be used to determine the value, hue, and chroma. Correct sizing of restorations according to the central incisor dominance principle improves not only esthetics but also aspects of occlusion, such as anterior guidance. Refractory porcelain systems can effectively restore the color, shape, emergence profile, and incisal translucency. This report illustrates the esthetic and occlusal rehabilitation of the dominance of maxillary central incisors using fabricated minimal thickness refractory porcelain veneers.

Abstract Introduction: Currently, due to increased demand of patients anddentists for aesthetic t... more Abstract Introduction: Currently, due to increased demand of patients anddentists for aesthetic treatments, bleaching procedures have becomeroutine in dental treatment. The development of new techniques andmaterials, such as laser-activated bleaching, has ...

Pediatric dentistry

Crown-root fractures are complex traumatic injuries that require multidisciplinary management and... more Crown-root fractures are complex traumatic injuries that require multidisciplinary management and afford uncertain prognosis. The purpose of this clinical article was to report the case of crown-root fracture where a multidisciplinary approach was successfully executed. A 10-year-old male patient who suffered a complicated crown-root fracture on a permanent maxillary central incisor was treated using an intentional 180°-rotation replantation technique, followed by endodontic therapy and restoration with resin composite. Two years after the initial treatment, the case was stable and the tooth was restored with a resin core and a ceramic crown. This article describes how adequate multidisciplinary treatment planning, coordination, and execution are necessary for similar cases to be properly managed. It can be concluded that the intentional replantation with 180°-rotation allowed a more conservative approach, showing, in this case, a clinical success without resorption.

Journal of dentistry for children (Chicago, Ill.)

The purpose of this study was to evaluate and compare the knowledge and attitudestowarddentalavul... more The purpose of this study was to evaluate and compare the knowledge and attitudestowarddentalavulsionofpublicandprivateelementaryschoolteachers. Methods:thestudywasperformedbyapplyingaquestionnaireinasamplecomposed of95elementaryschoolteachers(46frompublicschoolsand49fromprivateschools). The questionnaire comprised 9 questions and was pretested before final implementation. Results:Thirty-nine percent of private schoolteachers and 15% of public schoolteachers witnessed at least 1 case of dental avulsion at the school (P=.009). Ninety-two percent and 62% of private and public schoolteachers, respectively, admitted the possibilityofanavulsionedtoothtobereimplanted(P<.001).Bothresponseswerestatistically different when school type (public or private) was considered. Only 27% of privateschoolteachersand11%ofpublicschoolteachersknewtheprocedurestobetaken in cases of avulsed teeth, and more than 95% of all teachers did not feel capable of executing tooth reimplantation.The study showed no statistical difference between privateandpublicschoolteachers'knowledge. Conclusions:Teachers and other professionals involved in children's care and supervision must be correctly and well informed about dental avulsion, its consequences andthecorrectprocedurestobeperformedinsuchcases.

Case Reports in Dentistry, 2015

A common problem encountered by dentists is the restorative treatment of nonvital teeth. When the... more A common problem encountered by dentists is the restorative treatment of nonvital teeth. When the pulp chamber presents appropriate conditions for retention, the endocrown is indicated. This monolithic, ceramic adhesive restoration is singularly used yet warrants wider recognition and use. The endocrown allows preservation of the tooth structure and is minimally invasive. Currently, this treatment option, of a core buildup and full coverage restoration, reduces tooth structure excessively. This treatment presents not only functional limitations but also aesthetic concerns. Recently, the VITA-PM9 system, a leucite-reinforced glass ceramic, has been increasingly used in a variety of clinical situations due to its satisfactory physical-mechanical and aesthetic properties. Therefore, the present study describes a case of surgical restoration of a nonvital tooth using the endocrown technique and the VITA-PM9.