Joe Ontiveros | The University of Texas Health Science Center at Houston (original) (raw)
Papers by Joe Ontiveros
The Journal of prosthetic dentistry, Jan 3, 2016
Many factors influence the quality of shade selection, and isolating how significantly each of th... more Many factors influence the quality of shade selection, and isolating how significantly each of these factors influences results is difficult. The purpose of this in vitro study was to compare results of shade matching using handheld lights with or without a polarizing filter with results obtained using a professional viewing booth and to analyze the influence of education and training on shade selection outcome. A total of 96 third-year dental students (evaluators) were randomly separated into 4 groups. Each group was assigned 1 of 2 handheld shade-matching devices (lights) with or without a polarizing filter. Each group performed a shade matching exercise using the handheld light or a professional viewing booth. The exercise consisted of matching shade tabs placed in a typodont to a commercial shade guide. Each group repeated this procedure 4 times over a 9-week period. A lecture on shade matching was presented at the fifth week of the study, between "before" and "af...
The Journal of Prosthetic Dentistry, 2015
Fractures of endodontically treated teeth have been attributed to weakened tooth structure caused... more Fractures of endodontically treated teeth have been attributed to weakened tooth structure caused by root canal enlargement and post preparation. The purpose of this in vitro study was to evaluate the fracture resistance of roots filled with either gutta percha, composite resin (LuxaCore Dual), or calcium silicate-based cement (Biodentine). One hundred twenty freshly extracted, human, permanent maxillary anterior teeth were sorted by type and assigned to 1 of 4 groups (n=30). The teeth in group NT were not endodontically treated and served as the control. The teeth in groups GP, LC, and, BD were accessed and instrumented to size 40/06. In group GP, the root canals were completely filled with gutta percha. In groups LC and BD, only the apical 5-mm portion of the root canals was filled with gutta percha, and the remaining portion of the root canals was filled with (LuxaCore Dual) in group LC and with (Biodentine) in group BD. Fracture resistance (kN) was assessed at the middle portion of each root, using a 3-point bending test with a universal testing machine exerting a compressive load on a loading pin at a crosshead speed of 0.5 mm/min until fracture occurred. One-way ANOVA was used to compare the mean root fracture resistance among the 4 groups (α=.05). The mean ± SD fracture loads were 2.13 ±0.53 kN for group NT, 1.97 ± 0.60 kN for group GP, 2.18 ±0.71 kN for group LC, and 2.22 ±0.54 kN for group BD. No statistically significant differences were found among the 4 groups (P>.05). The roots of endodontically treated maxillary anterior permanent incisors filled with gutta percha, Biodentine, or LuxaCore Dual had resistance to fracture similar to that of teeth that were not endodontically treated.
Journal of dentistry for children (Chicago, Ill.)
The purpose of this study was to determine if crimping the lingual aspect of commercially availab... more The purpose of this study was to determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings. Twenty-six anterior NuSmile crowns (size A1) were divided into 2 groups: group 1 served as the control, and group 2 was manually crimped evenly on the lingual cervical portion. All crowns were cemented onto a screw-mounted resin core duplicated from a manually prepared Kilgore tooth and tested under compression. Recorded were fracture resistance, percent of veneer facing loss, and fracture to the gingival margin. Differences between the control and experimental groups were analyzed by independent t test and chi-square (alpha=0.05). The mean shear force required to fracture the veneers of the noncrimped crowns was 510.11 N (+/-79.66 SD), and 511.02 N (+/-62.37) for the crimped crowns. The mean percentage of veneer facing removed in the noncrimped crowns was 33% (+/-12.18), and 43% (+/-14.30) in the crimped crowns. No significant difference in shear strengths (P=.970) and in percentage of veneer loss (P=.063) was shown between crimped and noncrimped crowns. A mean of 8% of the noncrimped crowns and 23% of the crimped crowns had veneers fracturing to the gingival margin. The chi-square test showed no significant difference (P=.297). The veneer resistance to fracture for the crimped crowns was comparable to noncrimped crowns. The crimped crowns, however, were associated with greater veneer surface area loss.
American journal of dentistry
A method for obtaining more predictable and accurate final impressions with polyvinylsiloxane imp... more A method for obtaining more predictable and accurate final impressions with polyvinylsiloxane impression materials in conjunction with stock trays is proposed and tested. Heavy impression material is used in advance for construction of a modified custom tray, while extra-light material is used for obtaining a more accurate final impression.
Objective: To evaluate the accelerated aging effects on color of different composite resins. Meth... more Objective: To evaluate the accelerated aging effects on color of different composite resins. Method: Shades were selected from two flowable composites, A1, A3, and White (WH), Filtek Supreme Ultra Flowable/3M ESPE (FSU); A1, A3 and Bleach (BL), Tetric EvoFlow/Ivoclar Vivadent (TEF), and A1, A3, and B1 micro-hybrid control (Filtek Z250/3M ESPE). Disc shaped specimens (10 mm X 2 mm, n=60) were polymerized using a halogen curing light (Demetron 501, Kerr/Demetron) for 40 seconds. Specimens were finished using 400-grit SiC paper and polished with a one-step polisher (PoGo, Dentsply/Caulk) for 40 seconds. Color measurements were taken at baseline (after 24 hour-storage in distilled water at 37°C) using a spectrophometer (Color-Eye 7000, GretagMacbeth) and after exposure to accelerated aging (150 kJ/m2) in a Weather-ometer (Ci35A, Atlas). Means and standard deviations were determined. The data were analyzed by analysis of variance. Fisher's PLSD intervals at a 0.05 level of significan...
Objective: To evaluate the shear bond strengths of three color-changing orthodontic adhesives and... more Objective: To evaluate the shear bond strengths of three color-changing orthodontic adhesives and a conventional light-cured adhesive to bovine enamel. Materials and Methods: Two hundred forty extracted bovine incisors were randomly divided into 8 groups of 30 teeth. The teeth were etched with 35% phosphoric acid (Transbond XT etching gel) and a primer (Transbond XT Primer) was applied. Metal orthodontic brackets (LP Twin Mini Master Series 0.022, American Orthodontics) were bonded directly to each tooth with three color-changing adhesives [Blugloo (BG, Ormco), Grengloo (GG, Ormco), Transbond PLUS (TP, 3M Unitek)], and a control [Transbond XT (TXT, 3M Unitek)]. The specimens were stored for 15 minutes and 24 hours in sodium azide at 37C. The specimens were debonded in shear on an Instron at 1.0 mm/min. The data were analyzed by two-way analysis of variance and post-hoc comparisons (Fisher's PLSD) at the 0.05 level of significance. Results: Means (n=30) with standard deviations i...
Objectives: To compare the shear bond strength of various self-etch and dual cure resin cements t... more Objectives: To compare the shear bond strength of various self-etch and dual cure resin cements to Premise facial and primary-dentin indirect composite. Methods: Sixty discs of Premise indirect composite (SDS/Kerr), d=5 mm, were fabricated and mounted in acrylic; thirty facial dentin composite and thirty primary dentin composite. The discs were polished using 320 grit paper, followed by Rocatec micro-abrasion and silane application. Cement cylinders, d=2.5, were bonded to an equal number of primary dentin and facial dentin composite discs according to the manufacturer’s instructions. The cements were Maxcem Elite (Kerr), Rely X Unicem Applicaps (3M ESPE), Clearfil Esthetic Cement with DC bond (Kuraray America), Rely X ARC with Single Bond (3M ESPE), Panavia F 2.0 (Kuraray America), and Nexus 3 (Kerr). Immediately after bonding, the specimens were immersed in water at 37°C for 24 hours. They were debonded using an Instron universal testing machine and shear bond strengths were calcul...
Objective: To evaluate the effect of polishing and accelerated aging on gloss of flowable resin c... more Objective: To evaluate the effect of polishing and accelerated aging on gloss of flowable resin composites. Method: Disc shaped specimens (D=10mm, 2-mm thick, n=5 per shade/polisher) were prepared using A1 and A3 shade of the following flowable resin composites: Tetric EvoFlow (TEF, Ivoclar Vivadent), Filtek Supreme Ultra Flowable (FSF, 3M ESPE), PermaFlo (PFL, Ultradent), and G-aenial Flo (GFL, GC). Upon removal of Mylar layer, specimens were polished using PoGo (PD, Dentsply Caulk, Milford, DE), and ProGloss (PA, Axis Dental) one-step polishers for 60 seconds. Gloss was measured using gloss-meter (Novo-curve, Rhopoint Instrumentation) before and after exposure to accelerated aging at 300 kJ/m2 (Atlas SUNTEST XXL, Atlas Material Testing Technology). Means and standard deviations were determined. The data were analyzed by analysis of variance and Fisher's PLSD intervals at a 0.05 level of significance. Result: Mean (sd) gloss before (GU,B) and after aging (G,A), and gloss retent...
Texas dental journal, 2011
The objectives of this study were to evaluate the debonding strength and mode of failure of a sel... more The objectives of this study were to evaluate the debonding strength and mode of failure of a selenium containing adhesive compared to an established orthodontic adhesive. One hundred sixty bovine mandibular incisors were allocated to eight groups: steel and clear brackets were bonded with either selenium containing adhesive (Group 1: SeLect Defense) or a conventional light-cured adhesive (Group 2:Transbond XT) to measure debond strength and the adhesive remnant index was used to assess the location of bond failure. Data was evaluated using a three-way analysis of variance and Fisher's PLSD multiple comparisons test for mean debond strengths. Group 2 debond strengths were greater than that of Group 1 with the steel and clear brackets. Group 1 debond strengths were greater with clear than with steel brackets at both time points. Both adhesives demonstrated increased debond strengths from zero to 24 hours and the clear brackets exhibited a greater ARI than steel after debonding. C...
Texas Dental Journal, Jun 1, 2011
The purpose of this study was to compare the force loss of 1/4 inch (6.35mm) 3.5oz (99g) medium l... more The purpose of this study was to compare the force loss of 1/4 inch (6.35mm) 3.5oz (99g) medium latex elastics from Ormco Corp. to non-latex elastics from ClassOne Orthodontics and Phoenix after being cycled between different temperatures. Elastics were stretched to 1.57 inches (40mm) on jigs and cycled in water baths for 4 minutes at 5 degrees C and 37 degrees C, 21 degrees C and 37 degrees C, 5 degrees C and 50 degrees C, 37 degrees C and 50 degrees C, and a control group was held at 3 degrees 7 degrees C. The force produced by new elastics and elastics after incubation was measured using a Mini 44 Instron. All elastics experienced increased force loss that correlated with increased temperatures with the exception of Ormco latex elastics. The latex elastics had the greatest force loss upon cycling between 5 degrees C and 50 degrees C while the non-latex elastics had the greatest force loss while cycling between 37 degrees C and 50 degrees C. All elastics were strongest when cycled between 5 degrees C and 37 degrees C. This study suggests that hot liquids reduce the force of latex and non-latex elastics even when cycled between hot temperatures for brief periods of time.
Texas dental journal, 2010
This study investigated whether tooth whitening with two different bleaching systems affects the ... more This study investigated whether tooth whitening with two different bleaching systems affects the shear bond strength achieved using an orthodontic self-etching primer. The sample of 210 bovine incisors was divided into three groups. One group served as the control, while the other two groups received either an over-the-counter "white strip" bleaching regimen (Opalescence TresWhite) or a "power bleaching" in-office regimen (Opalescence Boost). Each bleaching group was divided into three groups to be tested at three time intervals post-bleaching: immediately, 24 hours, and 7 days. When compared to the control, the shear bond strength attained on Opalescence TresWhite treated specimens was not significantly lower at any time interval post-bleaching. Immediately after bleaching and 24 hours after bleaching, the Opalescence Boost treated groups showed significantly lower shear bond strengths than both the control groups and the Opalescence TresWhite groups. Bleaching ...
Texas dental journal, 2009
By the 1980's, bonding of orthodontic brackets had become the routine technique for attaching... more By the 1980's, bonding of orthodontic brackets had become the routine technique for attaching fixed appliances to teeth, replacing the need to fit and cement bands on each tooth (1). This modification in appliance attachment revolutionized orthodontics. Before, each tooth required a band. This meant a band must be fitted, have a bracket welded to it, and be cemented onto each tooth. Not only was this process time consuming and frustrating, but it meant 4 to 6 millimeters of space per arch was needed to seat the bands. Many cases that perhaps could have been treated without tooth extraction ended up needing extractions to accommodate the band space.
Journal of dentistry for children (Chicago, Ill.)
The purpose of this study was to determine if crimping the lingual aspect of commercially availab... more The purpose of this study was to determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings. Twenty-six anterior NuSmile crowns (size A1) were divided into 2 groups: group 1 served as the control, and group 2 was manually crimped evenly on the lingual cervical portion. All crowns were cemented onto a screw-mounted resin core duplicated from a manually prepared Kilgore tooth and tested under compression. Recorded were fracture resistance, percent of veneer facing loss, and fracture to the gingival margin. Differences between the control and experimental groups were analyzed by independent t test and chi-square (alpha=0.05). The mean shear force required to fracture the veneers of the noncrimped crowns was 510.11 N (+/-79.66 SD), and 511.02 N (+/-62.37) for the crimped crowns. The mean percentage of veneer facing removed in the noncrimped crowns was 33% (+/-12.18), and 4...
ABSTRACT Objective: To compare the bond strengths of two color change orthodontic adhesives when ... more ABSTRACT Objective: To compare the bond strengths of two color change orthodontic adhesives when used with three different aesthetic brackets. Methods: Three hundred sixty extracted bovine incisors were randomly divided into 18 groups of 20 teeth. After the application of a self etching primer (Transbond Plus Self Etch Primer, 3M Unitek), three types of aesthetic brackets (Clarity, 3M Unitek, CL; Radiance, American Orthodontics, R; Damon D3, Ormco, D3) were bonded using three types of orthodontic adhesives (Transbond XT, 3M Unitek, TBXT; Transbond Plus Color Change Adhesive, 3M Unitek, TB-Pink; Blugloo, Ormco, BG). The specimens were stored in sodium azide at 37C. Each bracket and adhesive combination was debonded immediately and at 24 hours in shear on an Instron at 1.0 mm/min. The data were analyzed by two-way analysis of variance and post-hoc comparisons (Fisher's PLSD) at the 0.05 level of significance. Results: Means (MPa) with standard deviations in parentheses are listed in Table 1 (n=20). Fisher's PLSD intervals for comparisons of means among cements, brackets and times were 1.0, 1.0 and 0.9 MPa, respectively, indicating significant differences among these factors. Bond strengths to bracket CL were the highest among brackets tested. Adhesive BG had higher immediate bond strengths than TBXT. Bond strengths generally increased from immediate to 24 hrs. The bond strengths were considered to be clinically acceptable (7.3-13.9MPa). Bracket/Adhesive 0 hrs 24 hrs CL/TBXT 11.1 (6.5) 13.6 (3.9) CL/TB-Pink 12.5 (2.8) 12.3 (4.8) CL/BG 13.8 (3.2) 13.0 (4.8) D3/TBXT 7.8 (2.4) 9.3 (1.7) D3/TB-Pink 8.3 (1.6) 8.8 (1.5) D3/BG 9.6 (2.3) 7.8 (3.1) R/TBXT 7.3 (3.4) 11.3 (4.4) R/TB-Pink 10.7 (5.6) 11.1 (6.1) R/BG 9.5 (6.1) 12.8 (5.0) Conclusions: Differences in shear bond strengths in-vitro among cements, brackets and time of testing were significant.
ABSTRACT Objective: to evaluate the effectiveness and color rebound effect of a 22% carbamide per... more ABSTRACT Objective: to evaluate the effectiveness and color rebound effect of a 22% carbamide peroxide (CP) at-home whitening system. Methods: A total of 21 subjects were recruited for an at-home tooth whitening clinical study. Subjects were treated overnight for 2 weeks with 22% CP (Venus White, Heraeus Kulzer). Visual color measurement was performed by three color normal evaluators using the Vita Classical (VC) and the 3D Bleachedguide (BG). Instrumental color measurements were performed using an intraoral spectrophotometer (Vita Easyshade Compact). Color measurements were taken on a canine and central incisor at baseline, 2, 3, and 4 weeks. Wilcoxon matched-pair signed-rank test for group comparisons and Bonferroni correction was used to adjust for multiple testing at the 0.05 level of significance. Results: Means (sd) for visual and instrumental whitening-dependent color changes are listed in the table; SGU=shade guide units, DE= total color change 2 weeks minus baseline 3 weeks minus baseline 4 weeks minus baseline Incisor Canine Incisor Canine Incisor Canine SGU(BG) 3.9(1.7) 5.8(2.1) 3.7(1.7) 5.6(2.3) 3.7(1.3) 5.4(2.2) SGU(VC) 5.2(2.8) 8.4(3.5) 4.9(2.4) 8.0(3.5) 4.8(2.5) 8.0(3.5) DE*(ES) 7.0(2.9) 10.2(4.7) 7.1(2.5) 9.1(4.8) 6.7(2.7) 9.9(4.2) For visual shade evaluation with VC and BG, there was a statistically significant decrease in SGU from baseline and each subsequent week among all measurements, p<0.001. For instrumental measurements, there was no difference from week 2 to week 3 for canines and generally no difference between week 3 and week 4 in all parameters for incisors. Conclusions: Visual and instrumental measurements evaluation showed clinical whitening-dependent rebound occurred 1 week post bleaching. In general, color stabilized at 2 weeks post bleaching.
ABSTRACT Objective: To determine the effect of self-etch adhesives and various laser conditioning... more ABSTRACT Objective: To determine the effect of self-etch adhesives and various laser conditioning methods on composite bond strengths to enamel. Methods: Extracted human teeth were divided into one of the following enamel surface conditioning groups: Laser/Er,Cr:YSGG (L), Laser + Excavation (LE), Laser + Excavation + Acid-etch (LEA) and a Bur Treatment Control (C). The conditioning groups were further divided into three self-etch adhesive subgroups: One-up Bond (OB), Bond Force (BF), and AdheSE One (AO). Adhesives were applied to conditioned enamel according to the manufacturer's instructions and bonded to composite (cylinder d =2.3mm) using a standard halogen curing light. Specimens were stored at 37C at 100% humidity for 24 hours and subjected to shear bond testing. Two-way ANOVA and Tukey's post hoc test for comparison of means were calculated at the 0.05 level of significance. Results: Means (SD) of enamel bond strengths (MPa) were: Adhesives Method OB BF AO Laser 10.1 (3.6) 11.7(4.3) 12.8(4.6) Laser + Excavation 10.4(3.5) 9.4(3.1) 11.8(3.8) Laser + Excavation + Acid Etch 19 (7.3) 15.5(5.2) 17.6(5.4) Bur Control 17.1(4.4) 15.1(3.4) 11.5(4.1) No significant difference in main effects among adhesives (p=0.46) was found. However, a significant difference was found for methods (p<0.01) and main effect interactions (p=0.046). Among method groups, LEA showed significantly higher bond strengths than L and LE (p<0.01), but not compared to the control (p=0.063). Conclusions: Enamel bond strength showed variable outcomes among adhesives dependent on laser conditioning methods. When treating enamel with a laser, the LEA technique showed high bond strengths on the same level as a bur control. Supported in part by Tokuyama Dental Corp. -------------------------
The Journal of prosthetic dentistry, Jan 3, 2016
Many factors influence the quality of shade selection, and isolating how significantly each of th... more Many factors influence the quality of shade selection, and isolating how significantly each of these factors influences results is difficult. The purpose of this in vitro study was to compare results of shade matching using handheld lights with or without a polarizing filter with results obtained using a professional viewing booth and to analyze the influence of education and training on shade selection outcome. A total of 96 third-year dental students (evaluators) were randomly separated into 4 groups. Each group was assigned 1 of 2 handheld shade-matching devices (lights) with or without a polarizing filter. Each group performed a shade matching exercise using the handheld light or a professional viewing booth. The exercise consisted of matching shade tabs placed in a typodont to a commercial shade guide. Each group repeated this procedure 4 times over a 9-week period. A lecture on shade matching was presented at the fifth week of the study, between "before" and "af...
The Journal of Prosthetic Dentistry, 2015
Fractures of endodontically treated teeth have been attributed to weakened tooth structure caused... more Fractures of endodontically treated teeth have been attributed to weakened tooth structure caused by root canal enlargement and post preparation. The purpose of this in vitro study was to evaluate the fracture resistance of roots filled with either gutta percha, composite resin (LuxaCore Dual), or calcium silicate-based cement (Biodentine). One hundred twenty freshly extracted, human, permanent maxillary anterior teeth were sorted by type and assigned to 1 of 4 groups (n=30). The teeth in group NT were not endodontically treated and served as the control. The teeth in groups GP, LC, and, BD were accessed and instrumented to size 40/06. In group GP, the root canals were completely filled with gutta percha. In groups LC and BD, only the apical 5-mm portion of the root canals was filled with gutta percha, and the remaining portion of the root canals was filled with (LuxaCore Dual) in group LC and with (Biodentine) in group BD. Fracture resistance (kN) was assessed at the middle portion of each root, using a 3-point bending test with a universal testing machine exerting a compressive load on a loading pin at a crosshead speed of 0.5 mm/min until fracture occurred. One-way ANOVA was used to compare the mean root fracture resistance among the 4 groups (α=.05). The mean ± SD fracture loads were 2.13 ±0.53 kN for group NT, 1.97 ± 0.60 kN for group GP, 2.18 ±0.71 kN for group LC, and 2.22 ±0.54 kN for group BD. No statistically significant differences were found among the 4 groups (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;amp;amp;amp;gt;.05). The roots of endodontically treated maxillary anterior permanent incisors filled with gutta percha, Biodentine, or LuxaCore Dual had resistance to fracture similar to that of teeth that were not endodontically treated.
Journal of dentistry for children (Chicago, Ill.)
The purpose of this study was to determine if crimping the lingual aspect of commercially availab... more The purpose of this study was to determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings. Twenty-six anterior NuSmile crowns (size A1) were divided into 2 groups: group 1 served as the control, and group 2 was manually crimped evenly on the lingual cervical portion. All crowns were cemented onto a screw-mounted resin core duplicated from a manually prepared Kilgore tooth and tested under compression. Recorded were fracture resistance, percent of veneer facing loss, and fracture to the gingival margin. Differences between the control and experimental groups were analyzed by independent t test and chi-square (alpha=0.05). The mean shear force required to fracture the veneers of the noncrimped crowns was 510.11 N (+/-79.66 SD), and 511.02 N (+/-62.37) for the crimped crowns. The mean percentage of veneer facing removed in the noncrimped crowns was 33% (+/-12.18), and 43% (+/-14.30) in the crimped crowns. No significant difference in shear strengths (P=.970) and in percentage of veneer loss (P=.063) was shown between crimped and noncrimped crowns. A mean of 8% of the noncrimped crowns and 23% of the crimped crowns had veneers fracturing to the gingival margin. The chi-square test showed no significant difference (P=.297). The veneer resistance to fracture for the crimped crowns was comparable to noncrimped crowns. The crimped crowns, however, were associated with greater veneer surface area loss.
American journal of dentistry
A method for obtaining more predictable and accurate final impressions with polyvinylsiloxane imp... more A method for obtaining more predictable and accurate final impressions with polyvinylsiloxane impression materials in conjunction with stock trays is proposed and tested. Heavy impression material is used in advance for construction of a modified custom tray, while extra-light material is used for obtaining a more accurate final impression.
Objective: To evaluate the accelerated aging effects on color of different composite resins. Meth... more Objective: To evaluate the accelerated aging effects on color of different composite resins. Method: Shades were selected from two flowable composites, A1, A3, and White (WH), Filtek Supreme Ultra Flowable/3M ESPE (FSU); A1, A3 and Bleach (BL), Tetric EvoFlow/Ivoclar Vivadent (TEF), and A1, A3, and B1 micro-hybrid control (Filtek Z250/3M ESPE). Disc shaped specimens (10 mm X 2 mm, n=60) were polymerized using a halogen curing light (Demetron 501, Kerr/Demetron) for 40 seconds. Specimens were finished using 400-grit SiC paper and polished with a one-step polisher (PoGo, Dentsply/Caulk) for 40 seconds. Color measurements were taken at baseline (after 24 hour-storage in distilled water at 37°C) using a spectrophometer (Color-Eye 7000, GretagMacbeth) and after exposure to accelerated aging (150 kJ/m2) in a Weather-ometer (Ci35A, Atlas). Means and standard deviations were determined. The data were analyzed by analysis of variance. Fisher's PLSD intervals at a 0.05 level of significan...
Objective: To evaluate the shear bond strengths of three color-changing orthodontic adhesives and... more Objective: To evaluate the shear bond strengths of three color-changing orthodontic adhesives and a conventional light-cured adhesive to bovine enamel. Materials and Methods: Two hundred forty extracted bovine incisors were randomly divided into 8 groups of 30 teeth. The teeth were etched with 35% phosphoric acid (Transbond XT etching gel) and a primer (Transbond XT Primer) was applied. Metal orthodontic brackets (LP Twin Mini Master Series 0.022, American Orthodontics) were bonded directly to each tooth with three color-changing adhesives [Blugloo (BG, Ormco), Grengloo (GG, Ormco), Transbond PLUS (TP, 3M Unitek)], and a control [Transbond XT (TXT, 3M Unitek)]. The specimens were stored for 15 minutes and 24 hours in sodium azide at 37C. The specimens were debonded in shear on an Instron at 1.0 mm/min. The data were analyzed by two-way analysis of variance and post-hoc comparisons (Fisher's PLSD) at the 0.05 level of significance. Results: Means (n=30) with standard deviations i...
Objectives: To compare the shear bond strength of various self-etch and dual cure resin cements t... more Objectives: To compare the shear bond strength of various self-etch and dual cure resin cements to Premise facial and primary-dentin indirect composite. Methods: Sixty discs of Premise indirect composite (SDS/Kerr), d=5 mm, were fabricated and mounted in acrylic; thirty facial dentin composite and thirty primary dentin composite. The discs were polished using 320 grit paper, followed by Rocatec micro-abrasion and silane application. Cement cylinders, d=2.5, were bonded to an equal number of primary dentin and facial dentin composite discs according to the manufacturer’s instructions. The cements were Maxcem Elite (Kerr), Rely X Unicem Applicaps (3M ESPE), Clearfil Esthetic Cement with DC bond (Kuraray America), Rely X ARC with Single Bond (3M ESPE), Panavia F 2.0 (Kuraray America), and Nexus 3 (Kerr). Immediately after bonding, the specimens were immersed in water at 37°C for 24 hours. They were debonded using an Instron universal testing machine and shear bond strengths were calcul...
Objective: To evaluate the effect of polishing and accelerated aging on gloss of flowable resin c... more Objective: To evaluate the effect of polishing and accelerated aging on gloss of flowable resin composites. Method: Disc shaped specimens (D=10mm, 2-mm thick, n=5 per shade/polisher) were prepared using A1 and A3 shade of the following flowable resin composites: Tetric EvoFlow (TEF, Ivoclar Vivadent), Filtek Supreme Ultra Flowable (FSF, 3M ESPE), PermaFlo (PFL, Ultradent), and G-aenial Flo (GFL, GC). Upon removal of Mylar layer, specimens were polished using PoGo (PD, Dentsply Caulk, Milford, DE), and ProGloss (PA, Axis Dental) one-step polishers for 60 seconds. Gloss was measured using gloss-meter (Novo-curve, Rhopoint Instrumentation) before and after exposure to accelerated aging at 300 kJ/m2 (Atlas SUNTEST XXL, Atlas Material Testing Technology). Means and standard deviations were determined. The data were analyzed by analysis of variance and Fisher's PLSD intervals at a 0.05 level of significance. Result: Mean (sd) gloss before (GU,B) and after aging (G,A), and gloss retent...
Texas dental journal, 2011
The objectives of this study were to evaluate the debonding strength and mode of failure of a sel... more The objectives of this study were to evaluate the debonding strength and mode of failure of a selenium containing adhesive compared to an established orthodontic adhesive. One hundred sixty bovine mandibular incisors were allocated to eight groups: steel and clear brackets were bonded with either selenium containing adhesive (Group 1: SeLect Defense) or a conventional light-cured adhesive (Group 2:Transbond XT) to measure debond strength and the adhesive remnant index was used to assess the location of bond failure. Data was evaluated using a three-way analysis of variance and Fisher's PLSD multiple comparisons test for mean debond strengths. Group 2 debond strengths were greater than that of Group 1 with the steel and clear brackets. Group 1 debond strengths were greater with clear than with steel brackets at both time points. Both adhesives demonstrated increased debond strengths from zero to 24 hours and the clear brackets exhibited a greater ARI than steel after debonding. C...
Texas Dental Journal, Jun 1, 2011
The purpose of this study was to compare the force loss of 1/4 inch (6.35mm) 3.5oz (99g) medium l... more The purpose of this study was to compare the force loss of 1/4 inch (6.35mm) 3.5oz (99g) medium latex elastics from Ormco Corp. to non-latex elastics from ClassOne Orthodontics and Phoenix after being cycled between different temperatures. Elastics were stretched to 1.57 inches (40mm) on jigs and cycled in water baths for 4 minutes at 5 degrees C and 37 degrees C, 21 degrees C and 37 degrees C, 5 degrees C and 50 degrees C, 37 degrees C and 50 degrees C, and a control group was held at 3 degrees 7 degrees C. The force produced by new elastics and elastics after incubation was measured using a Mini 44 Instron. All elastics experienced increased force loss that correlated with increased temperatures with the exception of Ormco latex elastics. The latex elastics had the greatest force loss upon cycling between 5 degrees C and 50 degrees C while the non-latex elastics had the greatest force loss while cycling between 37 degrees C and 50 degrees C. All elastics were strongest when cycled between 5 degrees C and 37 degrees C. This study suggests that hot liquids reduce the force of latex and non-latex elastics even when cycled between hot temperatures for brief periods of time.
Texas dental journal, 2010
This study investigated whether tooth whitening with two different bleaching systems affects the ... more This study investigated whether tooth whitening with two different bleaching systems affects the shear bond strength achieved using an orthodontic self-etching primer. The sample of 210 bovine incisors was divided into three groups. One group served as the control, while the other two groups received either an over-the-counter "white strip" bleaching regimen (Opalescence TresWhite) or a "power bleaching" in-office regimen (Opalescence Boost). Each bleaching group was divided into three groups to be tested at three time intervals post-bleaching: immediately, 24 hours, and 7 days. When compared to the control, the shear bond strength attained on Opalescence TresWhite treated specimens was not significantly lower at any time interval post-bleaching. Immediately after bleaching and 24 hours after bleaching, the Opalescence Boost treated groups showed significantly lower shear bond strengths than both the control groups and the Opalescence TresWhite groups. Bleaching ...
Texas dental journal, 2009
By the 1980's, bonding of orthodontic brackets had become the routine technique for attaching... more By the 1980's, bonding of orthodontic brackets had become the routine technique for attaching fixed appliances to teeth, replacing the need to fit and cement bands on each tooth (1). This modification in appliance attachment revolutionized orthodontics. Before, each tooth required a band. This meant a band must be fitted, have a bracket welded to it, and be cemented onto each tooth. Not only was this process time consuming and frustrating, but it meant 4 to 6 millimeters of space per arch was needed to seat the bands. Many cases that perhaps could have been treated without tooth extraction ended up needing extractions to accommodate the band space.
Journal of dentistry for children (Chicago, Ill.)
The purpose of this study was to determine if crimping the lingual aspect of commercially availab... more The purpose of this study was to determine if crimping the lingual aspect of commercially available, preveneered, anterior stainless steel primary crowns affects the fracture resistance of the veneer facings. Twenty-six anterior NuSmile crowns (size A1) were divided into 2 groups: group 1 served as the control, and group 2 was manually crimped evenly on the lingual cervical portion. All crowns were cemented onto a screw-mounted resin core duplicated from a manually prepared Kilgore tooth and tested under compression. Recorded were fracture resistance, percent of veneer facing loss, and fracture to the gingival margin. Differences between the control and experimental groups were analyzed by independent t test and chi-square (alpha=0.05). The mean shear force required to fracture the veneers of the noncrimped crowns was 510.11 N (+/-79.66 SD), and 511.02 N (+/-62.37) for the crimped crowns. The mean percentage of veneer facing removed in the noncrimped crowns was 33% (+/-12.18), and 4...
ABSTRACT Objective: To compare the bond strengths of two color change orthodontic adhesives when ... more ABSTRACT Objective: To compare the bond strengths of two color change orthodontic adhesives when used with three different aesthetic brackets. Methods: Three hundred sixty extracted bovine incisors were randomly divided into 18 groups of 20 teeth. After the application of a self etching primer (Transbond Plus Self Etch Primer, 3M Unitek), three types of aesthetic brackets (Clarity, 3M Unitek, CL; Radiance, American Orthodontics, R; Damon D3, Ormco, D3) were bonded using three types of orthodontic adhesives (Transbond XT, 3M Unitek, TBXT; Transbond Plus Color Change Adhesive, 3M Unitek, TB-Pink; Blugloo, Ormco, BG). The specimens were stored in sodium azide at 37C. Each bracket and adhesive combination was debonded immediately and at 24 hours in shear on an Instron at 1.0 mm/min. The data were analyzed by two-way analysis of variance and post-hoc comparisons (Fisher's PLSD) at the 0.05 level of significance. Results: Means (MPa) with standard deviations in parentheses are listed in Table 1 (n=20). Fisher's PLSD intervals for comparisons of means among cements, brackets and times were 1.0, 1.0 and 0.9 MPa, respectively, indicating significant differences among these factors. Bond strengths to bracket CL were the highest among brackets tested. Adhesive BG had higher immediate bond strengths than TBXT. Bond strengths generally increased from immediate to 24 hrs. The bond strengths were considered to be clinically acceptable (7.3-13.9MPa). Bracket/Adhesive 0 hrs 24 hrs CL/TBXT 11.1 (6.5) 13.6 (3.9) CL/TB-Pink 12.5 (2.8) 12.3 (4.8) CL/BG 13.8 (3.2) 13.0 (4.8) D3/TBXT 7.8 (2.4) 9.3 (1.7) D3/TB-Pink 8.3 (1.6) 8.8 (1.5) D3/BG 9.6 (2.3) 7.8 (3.1) R/TBXT 7.3 (3.4) 11.3 (4.4) R/TB-Pink 10.7 (5.6) 11.1 (6.1) R/BG 9.5 (6.1) 12.8 (5.0) Conclusions: Differences in shear bond strengths in-vitro among cements, brackets and time of testing were significant.
ABSTRACT Objective: to evaluate the effectiveness and color rebound effect of a 22% carbamide per... more ABSTRACT Objective: to evaluate the effectiveness and color rebound effect of a 22% carbamide peroxide (CP) at-home whitening system. Methods: A total of 21 subjects were recruited for an at-home tooth whitening clinical study. Subjects were treated overnight for 2 weeks with 22% CP (Venus White, Heraeus Kulzer). Visual color measurement was performed by three color normal evaluators using the Vita Classical (VC) and the 3D Bleachedguide (BG). Instrumental color measurements were performed using an intraoral spectrophotometer (Vita Easyshade Compact). Color measurements were taken on a canine and central incisor at baseline, 2, 3, and 4 weeks. Wilcoxon matched-pair signed-rank test for group comparisons and Bonferroni correction was used to adjust for multiple testing at the 0.05 level of significance. Results: Means (sd) for visual and instrumental whitening-dependent color changes are listed in the table; SGU=shade guide units, DE= total color change 2 weeks minus baseline 3 weeks minus baseline 4 weeks minus baseline Incisor Canine Incisor Canine Incisor Canine SGU(BG) 3.9(1.7) 5.8(2.1) 3.7(1.7) 5.6(2.3) 3.7(1.3) 5.4(2.2) SGU(VC) 5.2(2.8) 8.4(3.5) 4.9(2.4) 8.0(3.5) 4.8(2.5) 8.0(3.5) DE*(ES) 7.0(2.9) 10.2(4.7) 7.1(2.5) 9.1(4.8) 6.7(2.7) 9.9(4.2) For visual shade evaluation with VC and BG, there was a statistically significant decrease in SGU from baseline and each subsequent week among all measurements, p<0.001. For instrumental measurements, there was no difference from week 2 to week 3 for canines and generally no difference between week 3 and week 4 in all parameters for incisors. Conclusions: Visual and instrumental measurements evaluation showed clinical whitening-dependent rebound occurred 1 week post bleaching. In general, color stabilized at 2 weeks post bleaching.
ABSTRACT Objective: To determine the effect of self-etch adhesives and various laser conditioning... more ABSTRACT Objective: To determine the effect of self-etch adhesives and various laser conditioning methods on composite bond strengths to enamel. Methods: Extracted human teeth were divided into one of the following enamel surface conditioning groups: Laser/Er,Cr:YSGG (L), Laser + Excavation (LE), Laser + Excavation + Acid-etch (LEA) and a Bur Treatment Control (C). The conditioning groups were further divided into three self-etch adhesive subgroups: One-up Bond (OB), Bond Force (BF), and AdheSE One (AO). Adhesives were applied to conditioned enamel according to the manufacturer's instructions and bonded to composite (cylinder d =2.3mm) using a standard halogen curing light. Specimens were stored at 37C at 100% humidity for 24 hours and subjected to shear bond testing. Two-way ANOVA and Tukey's post hoc test for comparison of means were calculated at the 0.05 level of significance. Results: Means (SD) of enamel bond strengths (MPa) were: Adhesives Method OB BF AO Laser 10.1 (3.6) 11.7(4.3) 12.8(4.6) Laser + Excavation 10.4(3.5) 9.4(3.1) 11.8(3.8) Laser + Excavation + Acid Etch 19 (7.3) 15.5(5.2) 17.6(5.4) Bur Control 17.1(4.4) 15.1(3.4) 11.5(4.1) No significant difference in main effects among adhesives (p=0.46) was found. However, a significant difference was found for methods (p<0.01) and main effect interactions (p=0.046). Among method groups, LEA showed significantly higher bond strengths than L and LE (p<0.01), but not compared to the control (p=0.063). Conclusions: Enamel bond strength showed variable outcomes among adhesives dependent on laser conditioning methods. When treating enamel with a laser, the LEA technique showed high bond strengths on the same level as a bur control. Supported in part by Tokuyama Dental Corp. -------------------------