Clinical performance of preheating thermoviscous composite resin for non-carious cervical lesions restoration: A 24-month randomized clinical trial

OBJECTIVES

This 24-month, double-blind, split-mouth randomized clinical trial aimed to compare the retention rates of a preheated thermoviscous composite resin (PHT) compared to a non-heated composite resin (NHT) in non-carious cervical lesions (NCCLs).

METHODS

A total of 120 restorations were restored on NCCLs using a preheated (VisCalor bulk, Voco GmbH) and a non-heated (Admira Fusion, Voco GmbH) composite resins with 60 restorations per group. A universal adhesive in the selective enamel conditioning was applied. In the PHT group, composite was heated at 68 °C for using a bench heater. In the NHT group, no heating was employed. Both restorative materials were dispensed into caps and inserted into the NCCLs. The restorations were evaluated at baseline, 6, 12, 18, and after 24 months of clinical service using the FDI criteria. Statistical analysis was performed with Kaplan-Meier estimation analysis for retention/fracture rate and Chi-square test for the other FDI parameters (α=0.05).

RESULTS

After 24 months 108 restorations were assessed. Seven restorations were lost (two for PHT group and five for NHT group), and the retention rates (95 % confidence interval [CI]) were 96.7 % (81.5-99.9) for PHT group and 90.8 % (81.1-96.0) for NHT group, with no statistical differences between them (p > 0.05). The hazard ratio (95 % CI) was 0.52 (0.27 to 1.01), with no significant difference within groups. In terms of all other FDI parameters that were assessed, all restorations were deemed clinically acceptable.

CONCLUSIONS

Both composites showed high rates of retention rates after 24 months.

CLINICAL SIGNIFICANCE

The clinical performance of the new preheated thermoviscous was found to be as good as the non-heated composite after 24-month of clinical evaluation in non-carious cervical lesions.

REGISTRATION OF CLINICAL TRIALS

RBR-6d6gxxz.

In-office dental bleaching in adolescents using 6% hydrogen peroxide with different application tips: randomized clinical trial

OBJECTIVE

Despite the availability of in-office bleaching gels with a 6% concentration of hydrogen peroxide (HP), these gels have not been evaluated in younger patients. They are commercially available with a tip, associated or not with a brush, where the tip with a brush spreads the gel over the entire surface to have a smaller thickness (thin layer) since the manufacturers indicate the application of a thin layer of gel. This randomized, split-mouth, double-blind clinical trial evaluated the efficacy of in-office bleaching with 6% HP in adolescents using different application tips, as well tooth sensitivity (TS) and aesthetic self-perception.

METHODOLOGY

Sixty participants were randomized for 6% HP self-mixing bleaching gel tip design: without brush and with brush. In-office bleaching was performed in 3 sessions of 50 minutes. Color change was evaluated using a digital spectrophotometer (ΔE ab , ΔE 00 , and ΔWI D ) and color guide (ΔSGU), the absolute risk and intensity of TS with a visual analogue scale and aesthetic self-perception with the oral aesthetic scale (a=0.05).

RESULTS

The groups achieved similar bleaching regardless of the application tip (p>0.05). However, only for ΔWI D , a significant mean difference (MD) was observed in the third week (MD 2.3; 95% CI 1.2 to 3.3; p < 0.001) and at one month (MD 1.6; 95% CI 0.6 to 2.6; p < 0.03) favoring the tip without brush. Regarding TS, 45% in the tip-without-brush group and 33% in the tip-with-brush group reported TS (odds ratio 0.61; 95% CI 0.29 to 1.28; p<0.02), with low TS intensity (MD 0.05; 95% CI -0.06 to 0.17; p>0.36). All patients reported improved aesthetic self-perception after bleaching (MD -1.3; 95% -1.8 to -0.9; p<0.001).

CONCLUSIONS

Regardless of the tip used bleaching with 6% HP achieved a bleaching efficacy and improved the aesthetic self-perception. However, a lower risk of TS for application using the tip with brush was observed.

Application Tip and Concentration of a Self-mixing Bleach: Hydrogen Peroxide Inside the Pulp Chamber, Color Change, and Amount of Bleaching Gel Used

PURPOSE

The objective of this study was to evaluate if the application method (tip with brush or tip without brush) and hydrogen peroxide (HP) concentration (6% or 35% self-mixing) of in-office bleaching gel influences the penetration of HP into the pulp chamber, color change, and the amount of bleaching gel used.

METHODS

Forty healthy premolars were randomly divided into the following five groups (n=8): no treatment; HP6% using a tip with a brush, HP6% using a tip without a brush, HP35% using a tip with a brush, and HP35% using a tip without a brush. After treatments, the HP concentration (μg/mL) within the pulp chamber was determined using UV-Vis spectrophotometry. The color change (ΔEab, ΔE00, and ΔWID) was evaluated using a digital spectrophotometer. The amount of gel used (g) in each group was measured using a precision analytical balance. Data from each test were submitted to parametric tests (α=0.05).

RESULTS

The tip with a brush resulted in a lower amount of HP inside the pulp chamber and less gel used when compared with the tip without a brush, regardless of HP concentration (p<0.05). However, regarding the tip used, although no significant difference was observed when HP35% was used (p>0.05), a higher whitening effect was observed when the 6% HP was applied without a brush as opposed to with a tip brush (p<0.05).

CONCLUSIONS

The use of a tip with a brush, regardless of the in-office bleaching gel concentration (6% or 35% self-mixing), presented a lower penetration and lower volume of spent gel when compared to a tip without brush. However, the whitening effect depended on the concentration of HP used.

Eighteen-month clinical evaluation of a new universal adhesive applied in the "no-waiting" technique: a randomized clinical trial

OBJECTIVE

The aim of this double-blind, randomized clinical trial was to evaluate the 6- and 18-month clinical performances of a new universal adhesive applied in the "no-waiting" (NW) technique to non-carious cervical lesions (NCCLs) using two evaluation criteria.

MATERIALS AND METHODS

One hundred and seventy-six restorations were assigned to four groups according to the adhesive system, adhesive strategy, and application mode: Prime&Bond Active (PB) applied using the etch-and-rinse (ER) and self-etch (SE) strategies with 20 s applications and Clearfil Universal Bond Quick (CQ) applied using the ER and SE strategies with the NW technique. The composite resin restorations were evaluated at baseline and after 6 and 18 months using the World Dental Federation (FDI) and US Public Health Service (USPHS) criteria. The Friedman repeated measures analysis of variance and Wilcoxon test were used for statistical analyses (α = 0.05).

RESULTS

No significant differences were observed among any of the groups or criteria after 6 months (p > 0.05). After 18 months, 10 restorations were lost (p > 0.05) (2 with PB-ER [95.5%; 95%CI: 92-100%], 4 with PB-SE [90.9%; 95%CI: 82-98%], 0 with CQ-ER [100%; 95%CI: 92-100%], and 4 with CQ-SE [90.9%; 82-98%]). The restorations performed with the SE strategy showed more marginal discrepancies than those performed with the ER strategy, mainly when the FDI criteria were used (p < 0.05). Those that used the PB-SE showed fewer marginal discrepancies than those that used the CQ-SE (FDI; p < 0.05). A few restorations showed marginal discrepancies after the USPHS analysis (p > 0.05).

CONCLUSIONS

The results when using the CQ-SE and -ER strategies with the NW technique were similar to those when using the PB-SE and -ER strategies in standard applications to non-carious cervical lesions after 6 and 18 months of clinical evaluation.

CLINICAL RELEVANCE

After 6 and 18 months, the application of Clearfil Universal Bond Quick with the "no-waiting" technique showed similar clinical performance compared to the standard application of Prime & Bond Active applied using the standard application time (20 s).

TRIAL REGISTRATION

ClinicalTrials.gov identifier RBR-5f9gps.

Five-year Randomized Clinical Trial on the Performance of Two Etch-and-rinse Adhesives in Noncarious Cervical Lesions

OBJECTIVES

To evaluate the 5-year clinical performance of two-step etch-and-rinse adhesives in noncarious cervical lesions (NCCL).

METHODS AND MATERIALS

The sample comprised 35 adults with at least two similar-sized NCCL. Seventy restorations were placed, according to one of the following groups: Adper Single Bond 2 (SB) and Ambar (AM). The restorations were placed incrementally using a resin composite (Opallis). The restorations were evaluated at baseline and after 6 and 18 months and 5 years using some items of the FDI criteria. The differences in the ratings of the two materials after 6 months, 18 months, and 5 years were performed with Friedman repeated measures ANOVA by rank and McNemar test for significance in each pair (α=0.05).

RESULTS

Five patients did not attend the 60-month recall. No significant differences were observed between the materials for any criteria evaluated. Twenty-one restorations failed (12 for SB and 9 for AM) after 60 months. Thus, the retention rate for SB at 60 months were 55.6% for SB and 71% for AM (p=0.32). After 60 months, 12 restorations (6 for SB and 6 AM) showed some loss of marginal adaptation (p=1.0). Slight marginal discoloration was observed in 10 restorations (6 for SB and 4 AM; p=0.91). Five restorations (2 for SB and 3 for AM) showed recurrences of caries (p=1.0).

CONCLUSIONS

Both two-step etch-and-rinse adhesives-Adper Single Bond 2, a polyalkenoic acid-containing adhesive, and Ambar, a 10-methacryloyloxydecyl dihydrogen phosphate (MDP)-containing adhesive-showed acceptable clinical performance after 60 months.

Evaluation of the Bond Strength of Densely Sintered Ceramics Subjected to Extended Firing

Introduction

Critical failures in ceramic materials can be caused by the processing mode, which includes all steps taken in the manufacture of a ceramic part, from molding to firing.

Purpose

To evaluate the effect of extended firing on bond strength in densely sintered ceramics of the zirconium reinforced lithium silicate, lithium disilicate, and feldspathic ceramic.

Materials and Methods

Three types of ceramics were evaluated: zirconium reinforced lithium silicate, lithium disilicate, feldspathic ceramic. A total of 6 ceramic blocks, two for each material were used in the study. Each block was cut into four square sections. A total of 24 ceramic surfaces were randomly distributed into 6 groups (n = 4 surfaces per group) divided according to the variables: heat treatment: conventional firing or extended firing; test time: immediate (24 hours after cementation) or longevity (after 1000 cycles of thermocycling). The bond strength tests were performed in a semi-universal test machine for microshear bond strength. For data analysis, the Shapiro-Wilk test was performed to evaluate the normality between the groups measured, and regarding homoscedasticity (homogeneity of variances) by the Bartlett test. The comparisons between the groups were made using the nonparametric Kruskal-Wallis test.

Results

There was no statistically significant difference of the resistance values in relation to the thermal treatment methods (conventional firing and extended firing) in any ceramic group (p <0.05). Among the times (immediate and long), there was a statistically significant difference (p <0.05), with higher resistance values for immediate time.

Conclusion

Extended firing did not influence the micro-shear bond strength of zirconium reinforced lithium silicate, lithium disilicate, feldspathic ceramic.

Influence of the geometry of the screwdriver-screw connection on the reverse torque of UCLA screws

The aim of this study was to evaluate the influence of the geometry of the screwdriver-screw connection on the reverse torque of UCLA screws after repeated cycles of tightening and loosening in an implant-supported prosthesis. Thirty sets of external hex titanium implants, UCLA abutments, and UCLA abutment screws were divided into 3 experimental groups (n = 10). In the square group, the implant and UCLA abutment system were mounted in an upright position using a screw with a square screwdriver-screw connection. In the hexagonal group, the implant and UCLA abutment system were mounted in an upright position using a screw with a hexagonal screwdriver-screw connection. In the hexalobular group, the implant and UCLA abutment system were mounted at 70° using a dynamic UCLA abutment and screw with a hexalobular screwdriver-screw connection. Ten alternating torque-reverse torque cycles were applied to each screw using a screwdriver fixed at the end of a digital torque meter. The screws with a square connection resulted in less loss of reverse torque than the other types. Screws with a hexagonal connection showed a statistically significant loss of torque initially but remained constant for the remaining cycles. For the screws with a hexalobular connection, the loss of torque was greater, and substantial deformation of the plastic in the microstructure was noted. The screwdriver-screw connection geometry had a direct influence on the reverse torque of UCLA screws, and the initial reverse torque of the abutment screws with a square connection was greater than that of the hexagonal and hexalobular designs.

Clinical effects of the exposure to red wine during at-home bleaching

OBJECTIVES

This clinical trial evaluated the effects of red wine exposure on the effectiveness of at-home bleaching with 10% carbamide peroxide, degree of tooth sensitivity, and levels of periodontal inflammatory markers.

METHOD AND MATERIALS

Eighty participants were assigned to two groups, namely, those who drank red wine (experimental group), and those who did not drink red wine (control group). The experimental group participants rinsed their mouths with 25 mL of red wine four times a day during the bleaching period. Shade evaluation was assessed visually by using the Vita Classical and Vita Easyshade techniques. Tooth sensitivity was evaluated by the numeric and visual analog scales, and the salivary and gingival crevicular fluids were collected for assessment of nitric oxide (NO) levels, a marker of inflammation. Differences in color change were analyzed by one-way analysis of variance (ANOVA). The absolute risks of tooth sensitivity were compared by the Fisher exact test. Tooth sensitivity intensity data sets for both the visual analog scale and the numeric rating scale were compared using the Wilcoxon signed rank test (α = .05). Repeated measures and two-way ANOVA followed by the Bonferroni test were used to assess time-course and differences between groups in NO production.

RESULTS

The bleaching technique was effective regardless of wine consumption (P > .05). Tooth sensitivity was classified as mild, with no differences between groups (P > .05). Red wine reduced both the gingival crevicular fluid and salivary levels of NO (P < .05).

CONCLUSION

Red wine does not interfere with the effectiveness and sensitivity of at-home teeth bleaching with 10% carbamide peroxide and protects against bleaching-induced inflammation.

Personality traits, psychosocial effects and quality of life of patients submitted to dental bleaching

Background

Perception is defined as the ability to distinguish through the senses. All perception is dependent on factors such as personality, previously lived experiences and cultural elements. When planning an aesthetic treatment, consider the way the patients perceive the changes and outcomes is essential for reaching their expectations. The objective of this study was to assess if there was predominance of a personality trait of patient undergoing dental bleaching and if this treatment could promote changes in this traits, in the psychosocial impact and quality of life of these individuals.

Methods

The assessment of personality characteristics, quality of life, psychosocial and self-perception was a cross-sectional observational study and it was carried out by applying questionnaires to 55 patients that were submitted to a clinical phase. The psychometric instruments used were NEO FFI-R (personality), PIDAQ (psychosocial effect) and WHOQOL-BREF (quality of life). Each test domain was prior and after bleaching by Wilcoxon Signed Rank test (α = 0.05). The internal consistencies of each scale were evaluated by Cronbach's alpha.

Results

No statistical significant differences among personality traits means were observed among participants but there was predominance of two predominant personality traits in this study: conscientiousness (45.5%) and extraversion (34.5%). In four test domains of the PIDAQ, significant differences were observed before and after dental bleaching. The overall perception of the PIDAQ was also statistically significant demonstrating an improvement. There were no differences on overall or specific domains scores of the WHOQOL before and after treatment.

Conclusions

Subjects who underwent dental treatment improved their self-confidence and reduced concerns about dental aesthetics, social and personality impact of dental alterations.

Trial registration

This study was conducted in parallel to a clinical investigation that aimed to evaluate tooth sensitivity related to dental bleaching technique and registered in REBEC clinical registry under protocol RBR-6pt2n3 in 13 November 2013.

Effect of surface treatments on the adhesive properties of metallic brackets on fluorotic enamel

OBJECTIVE

To compare the effectiveness of the pretreatment with sandblasting and deproteinization with NaOCl on bond strength (SBS), in situ conversion degree (CD) of brackets in fluorotic enamel, and enamel etching pattern.

METHODS

A total of 90 non-carious maxillary premolars were used. The teeth were then assigned to six experimental groups according to: enamel surface (sound and fluorotic enamel); surface treatment (Regular etch with 37% phosphoric acid [RE]; 5.2% sodium hypochlorite + phosphoric acid [NaOCl + RE]; sandblasting + phosphoric acid [sandblasting + RE]). After storage in distilled water (37°C/24h), the specimens were tested at 1 mm/min until failure (SBS). Enamel-resin cement interfaces were evaluated for CD using micro-Raman spectroscopy. The enamel-etching pattern was evaluated under a scanning electron microscope. Data from SBS and in situ CD values were analyzed using ANOVA two-away and Tukey test (α=0.05). The enamel etching pattern was evaluated only qualitatively.

RESULTS

For sound enamel, RE showed the highest SBS values, when compared to NaOCl + RE and Sandblasting + RE groups (p< 0.01). Regarding CD, only NaOCl + RE significantly compromised the mean DC, in comparison with other groups (p= 0.002). For fluorotic enamel, the Sandblasting + RE group significantly increased the mean SBS values, in comparison with RE group (p= 0.01) and no significant change was observed for CD (p> 0.52).

CONCLUSIONS

The application of NaOCl or sandblasting associated to phosphoric acid improved the SBS of the brackets in fluorotic enamel without compromising the CD of the resin cement, with improving of enamel interprismatic conditioning.

Effects of Exposure to Cola-Based Soft Drink on Bleaching Effectiveness and Tooth Sensitivity of In-Office Bleaching: A Blind Clinical Trial

OBJECTIVE

The purpose of this single-blind (evaluators) and parallel design study was to evaluate whether exposure to a cola-based soft drink during bleaching treatment with 35% hydrogen peroxide (HP) affects color change and bleaching-induced tooth sensitivity.

MATERIAL AND METHODS

Forty-four patients with central incisors darker than A2 were selected. Participants who did not drink cola-based soft drinks were assigned to the control group (CG), while participants who drank a cola-based soft drink at least twice a day were assigned to the experimental group (EG). For the CG, foods with staining dyes were restricted. For the EG, there was no restriction on food and patients were asked to rinse their mouths with a cola-based soft drink for 30 s, 4 times daily. For both groups, 2 sessions with three 15 min applications of 35% HP were performed. Shade evaluation was assessed via subjective (VITA classical and VITA bleacheguide shade guides) and objective methods (Easyshade spectrophotometer) at baseline, during bleaching (first, second, and third weeks), and post bleaching (1 week and 1 month). Patients recorded their sensitivity perceptions using a numerical rating scale and 0-10 visual analog scales. Variation in shade guide units and the 2 colors (DE) were evaluated with a Student's t-test (α = 0.05) and Mann-Whitney test (α = 0.05). Absolute risk of tooth sensitivity and intensity of tooth sensitivity were evaluated by a Chi-square test (α=0.05).

RESULTS

Effective bleaching was observed for both groups after 30 days, without statistical difference (p > 0.08). There was no significant difference in absolute risk of bleaching-induced tooth sensitivity between the 2 groups (p = 0.74). Higher and significant scores in pain scales were detected for the EG in comparison to the CG (p < 0.05).

CONCLUSION

Even that the cola-based soft drink exposure during in-office bleaching treatments did not affect the bleaching's effectiveness; patients reported a higher intensity in bleaching-induced tooth sensitivity.

Bonding Performance of Universal Adhesive Systems Applied in Etch-and-Rinse and Self-Etch Strategies on Natural Dentin Caries

Objective:

This study investigated the bonding performance of three universal adhesive systems applied using etch-and-rinse (ER) or self-etch (SE) strategies on natural dentin caries.

Materials and Methods:

Sixty human third molars were selected for this study: 30 naturally carious (CAD) and 30 sound (SD) teeth. The dentin surfaces were exposed, and teeth were randomly assigned to each evaluated adhesive system: Scotchbond Universal (SBU), Futurabond U (FBU), and Prime&Bond Elect (PBE) and an adhesive strategy: ER or SE. The adhesive systems were applied following the manufacturer's instructions, and the teeth were restored using a resin composite (Filtek Supreme Ultra, 3M). After 24 hours (distilled water at 37°C), samples were sectioned and evaluated using microtensile bond strength analysis (μTBS), micro-Raman spectroscopy to evaluate the degree of conversion within the hybrid layer (DC), and scanning electronic microscopy (SEM) to describe the morphology of the hybrid layer. The μTBS and DC data were analyzed using three-way analysis of variance and Tukey's test for means comparison (α=0.05). The SEM images were analyzed qualitatively.

Results:

Reduced μTBS values were observed when comparing CAD with SD, regardless of adhesive system or strategy (p&lt;0.0001). SBU showed statistically higher μTBS for both dentin substrates and strategies (p&lt;0.0001). Furthermore, SBU showed greater integrity of the hybrid layer and resin tag formation compared with FBU and PBE. Mean μTBS values for FBU were higher for SD in the SE mode, whereas higher mean μTBS values were observed for CAD in the ER mode, both compared with PBE (p&lt;0.001).

Conclusion:

Bonding performance is reduced on a caries-affected substrate. The ER strategy was not able to improve the bonding performance on natural CAD for universal adhesive systems. Improved bonding performance was obtained when using the Scotchbond Universal system.

Effect of Phosphoric Acid Containing MMP-Inactivator on the Properties of Resin Bonding to Eroded Dentin

PURPOSE

To evaluate the effect of two phosphoric acids containing protease inactivators (chlorhexidine and proanthocyanidin) on the resin/eroded-dentin microtensile bond strength (μTBS), nanoleakage (NL), and in situ degree of conversion (DC) of three universal adhesives applied in the etch-and-rinse mode.

MATERIALS AND METHODS

One hundred twenty-six molars were randomly assigned to 18 experimental conditions according to the combination of the independent variables: eroded dentin (soft drink and citric acid), adhesive (Prime&Bond Elect [PBE, Dentsply Sirona], Scotchbond Universal Adhesive [SBU, 3M Oral Care], and Tetric N-Bond Universal [TEU, Ivoclar Vivadent]), and acid pretreatment (conventional phosphoric acid [CP acid]; chlorhexidine acid [CHX acid]; and proanthocyanidin acid [PA acid]). After restorations, specimens were sectioned into resin-dentin sticks (ca 0.8 mm2) that were then tested under tension (crosshead speed: 0.5 mm/min). Selected sticks from each tooth were used to evaluate NL and DC. Data from all tests were subjected to three-way ANOVA and Tukey's test (α=0.05).

RESULTS

Dentin eroded with citric acid showed a significant reduction in μTBS for each adhesive in comparison to dentin eroded with the soft drink (p < 0.001). For dentin eroded with CHX acid and PA acid, the μTBS (p > 0.03) significantly improved and NL decreased for all adhesives (p < 0.004); in addition, the DC improved for two of the three adhesives tested (SBU and TEU) (p < 0.03) when CHX acid and PA acid were compared to CP acid.

CONCLUSION

The addition of chlorhexidine and proanthocyanidin to phosphoric acid improved the adhesive performance when compared with conventional phosphoric acid, without jeopardizing adhesive polymerization at the resin/eroded-dentin interface.

Two-year Effects of Chlorhexidine-containing Adhesives on the In Vitro Durability of Resin-dentin Interfaces and Modeling of Drug Release

OBJECTIVES

To evaluate the effects of addition of diacetate chlorhexidine (CHX) at different concentrations into two etch-and-rinse adhesive systems on CHX release, as well as the immediate (IM) and two-year (2-Y) resin-dentin microtensile bond strength (μTBS) and nanoleakage (NL).

METHODS

CHX was added to XP Bond (XP) and Ambar (AM) at concentrations of 0.0 wt% (control); 0.01 wt%; 0.05 wt%; and 0.1 to 0.2 wt%. To assess the cumulative CHX release, adhesive disks were made in a metallic matrix and after light-curing were stored in water. Ultraviolet spectrophotometric measurements of the storage solution were performed to examine the release kinetics of CHX. For μTBS and NL, the occlusal enamel of molars was removed and the adhesives were applied to the dentin surface after acid etching. After composite resin build-up, specimens were sectioned to obtain μTBS sticks. The specimens were subjected to μTBS and NL at IM and after 2-Y. In addition, specimens underwent examination for CHX using micro-Raman spectroscopy. All data were submitted to statistical analysis (α=0.05).

RESULTS

With regard to CHX release, AM showed a slower and gradual release of CHX while XP released CHX more quickly ( p<0.05), and CHX was still present in the hybrid layers after 2-Y. Both adhesives showed CHX release at 2-Y water storage. Both CHX-containing adhesives showed higher μTBS values than did the control group ( p<0.05).

Two-Year Follow-up of Multidisciplinary Treatment Using Digital Smile Design as a Planning Tool for Esthetic Restorations on Maxillary Midline Diastema

One of the challenges posed by diastema closure treatment in the presence of tooth size discrepancy is to achieve adequate distribution of the spaces between the teeth. The use of the Digital Smile Design can assist the clinician in visualizing and measuring dentogingival discrepancies with maximum predictability. The present clinical case describes an approach to space distribution with assistance of the digital tool, allowing adequate restorative procedures. The protocol used was shown to be efficient, achieving the esthetics desired by the patient both during and after multidisciplinary treatment, as well as having adequate stability.

Bonding Performance of Universal Adhesives to Eroded Dentin

PURPOSE

To evaluate the microtensile bond strength (µTBS) and nanoleakage (NL) of several universal adhesives to eroded dentin (ED), using etch-and-rinse (ER) or self-etch (SE) strategies, and to characterize the surface using two pH cycling models to erode dentin (citric acid and a soft drink).

MATERIALS AND METHODS

Molars were eroded either by soft-drink or citric acid cycling, or were left untreated as control (SD). For each surface, the following adhesives were applied: 1. All-Bond Universal; 2. Ambar Universal; 3. Clearfil Universal; 4. Futurabond U; 5. One Coat 7 Universal; 6. Peak Universal Bond; 7. Prime&Bond Elect; 8. Scotchbond Universal; 9. Tetric n-bond Universal, and 10. Xeno Select. After application of the composite, specimens were sectioned into composite-dentin sticks and tested under tension (0.5 mm/min). Selected sticks from each tooth were used to assess NL. The occlusal dentin surfaces after erosive cycling were examined using SEM. Data were analyzed by three-way ANOVA and Tukey's post-hoc test (a = 0.05).

RESULTS

In ED, there was no difference in μTBS and NL between ER and SE strategies (p > 0.61). Most μTBS and NL values obtained for ED were, respectively, lower and higher than those for SD (p < 0.01), being worse for citric acid ED (p < 0.001). Citric-acid-eroded dentin showed more enlarged tubules, with partial loss of peritubular dentin when compared to soft-drink eroded dentin.

CONCLUSION

The different pH cycling models reduced μTBS and increased NL of the composite/eroded-dentin interface; however, in ED, the performance of the universal adhesives did not depend on the adhesive strategy used.

Impacto do pH e Tempo de Aplicação do Ácido Meta-Fosfórico na Longevidade da Interface Resina-Dentina

Avaliar o efeito de diferentes pHs do ácido meta-fosfórico 40% (MPA) em comparação com o ácido ortofosfórico convencional 37% (OPA) em diferentes tempos de aplicação na longevidade da resistência da união (µTBS), nanoinfiltração (NL) e alterações químicas (ATR-FTIR) da superfície dentinária. Molares humanos (n84) foram distribuídos aleatoriamente em 12 condições experimentais de acordo com a combinação de variáveis: Ácido [ácido ortofosfórico 37% (OPA), ácido metafosfórico 40% (MPA) em pH 0,5, 1 e 2] e Tempo de Aplicação [7, 15 e 30s]. Os dentes foram restaurados e seccionados para se obter palitos de resina-dentina para µTBS e NL testados imediatamente ou após 6 meses de armazenamento em água. Para NL, 3 palitos de cada dente/período foram analisados. 21 dentes foram utilizados para as análises químicas (ATR-FTIR) de acordo com o tempo de aplicação vs. tempo de armazenamento. Os dados foram submetidos a ANOVA de três fatores e teste de Tukey (a0,05). MPA pH 0,5 mostrou µTBS semelhante ao OPA, independentemente do tempo de aplicação (p> 0,05). Foram observadas diminuições significativas na µTBS e aumentos de NL somente para OPA após 6 meses (p0,001). OPA proporcionou valores de NL estatisticamente mais elevados do que MPA (p 0,003). Em ATR-FTIR, dentina desmineralizada representou picos de brushite e fosfato octacálcico. Contudo, os resultados de MPA foram dependentes do pH/tempo de aplicação. O uso de MPA preservou a interface resina-dentina em um período de 6 meses apresentado a presença de brushite e fosfato octacálcicoPalavras-chave: Adesivos Dentinário. Resistência à Tração. Ácidos Fosfóricos.

Three-Year Effects of Deproteinization on the In Vitro Durability of Resin/Dentin-Eroded Interfaces

Objective:

To evaluate the effect of sodium hypochlorite on the immediate and three-year bonding properties of a resin-eroded dentin interface produced by one of two adhesive strategies.

Methods and Materials:

Forty-eight molars were randomly assigned to six experimental groups, according to the combination of the adhesive strategy (etch-and-rinse and self-etch) and the dentin surface (control groups without erosion, eroded dentin surface [ED], and eroded dentin surface + NaOCl 5.2% [ED + NaOCl]). After completing restoration, specimens were stored in water (37°C) for 24 hours and then sectioned into resin–dentin beams (0.8 mm2) to be tested under tension (0.5 mm/min) immediately thereafter or after three years of water storage. To assess nanoleakage (NL), specimens were immersed in silver nitrate solution and examined by scanning electron microscopy at both time points. The dentin-etching pattern was examined under a scanning electron microscope. Data were subjected to appropriate statistical analysis (α=0.05)

Results:

In both strategies, a more pronounced and significant reduction of the microtensile bond strength (μTBS) values was observed for the ED groups (p=0.0001) after three years. However, in the ED + NaOCl group, μTBS values were maintained after three years of water storage. Furthermore, application of NaOCl to eroded dentin significantly reduced the immediate NL values and also preserved these values after three years of water storage for both adhesive strategies (p&gt;0.05). When considering the ED group, a superficial removal of the smear layer and enlarged lumen tubules in comparison to control were present. However, for ED + NaOCl, there was a total removal of the smear layer and significant numbers of collagen fibrils were exposed.

Conclusion:

The use of NaOCl may maintain the long-term stability of a resin-eroded dentin interface formed by etch-and-rinse and self-etch adhesives.

Evaluation of several clinical parameters after bleaching with hydrogen peroxide at different concentrations: A randomized clinical trial

OBJECTIVE

This randomized double-blind clinical trial compared tooth sensitivity (TS), bleaching efficacy, and cytokine levels after applying in-office bleaching treatments containing 15% and 35% hydrogen peroxide (HP15% and HP35%, respectively).

METHODS

Twenty-five volunteers were randomly assigned to receive HP15% or HP35% treatment. The bleaching agent was applied in three 15-min applications per session. Two bleaching sessions were separated by a 1-week interval. The participants scored TS using a visual analog scale and numerical rating scale. Bleaching efficacy was determined by subjective and objective methods. Gingival crevicular fluid was collected from three jaws sites per patient for the analysis of fluid volume. Flow cytometry was used to analyze gingival crevicular fluid levels of interleukin (IL)-1β, IL-2, IL-4, IL-6, IL-10, tumor necrosis factor, and interferon-gamma. All measurements were obtained before and after bleaching. All data were statistically analyzed (α=0.05).

RESULTS

The absolute risk and intensity of TS was higher for HP35% than for HP15% (p>0.002). One month post-bleaching, HP35% produced more bleaching than HP15% (p=0.02). However patient perception (p=0.06) and patient satisfaction (p=0.53) with regard to bleaching were not significantly different. No significant differences existed in the gingival fluid volume (p>0.38) or in any cytokine level (p>0.05) for either HP concentration.

CONCLUSION

Treatment: with HP35% is more effective than HP15%, but generates a greater risk and intensity of TS. No inflammatory changes occurred despite the difference in the HP concentrations.

CLINICAL SIGNIFICANCE

Hydrogen peroxide at a lower concentration (e.g., 15%) should be considered a good treatment alternative for in-office bleaching because the higher concentration for in-office bleaching generates a greater risk and intensity of TS for patients.

Acid Etching with Modified Phosphoric Acid to Increase the Longevity of the Bonded Interface

PURPOSE

To evaluate the effect of three phosphoric acids modified with chlorhexidine (CHX), benzalkonium chloride (BAC), or proanthocyanidins (PRO) and one conventional phosphoric acid (CON) on the immediate (24 h; IM) and 1-year composite-dentin microtensile bond strength (μTBS) and nanoleakage (NL), using an etch-and-rinse adhesive.

MATERIALS AND METHODS

A flat dentin surface was exposed on 28 caries-free extracted molars, which were then randomly assigned to four groups (n = 7). After etching and rinsing with one phosphoric acid per group, the adhesive (Adper Single Bond 2) was applied on a moist dentin surface. Composite buildups (Filtek Z350) were constructed incrementally and bonded stick specimens (0.8 mm2) were prepared and submitted to the microtensile test (0.5 mm/min) immediately (24 h) or after 1 year of water storage. For nanoleakage, 2 bonded sticks from each tooth at each storage period were immersed in 50 wt% ammoniacal silver nitrate, polished, and analyzed by SEM in backscattered mode. Data were submitted to a two-way ANOVA and Tukey's test (α = 0.05).

RESULTS

After 1 year, stable μTBS values were observed only for the modified phosphoric acids (CHX, BAC, and PRO). Also, NL was more evident in the CON group than in the CHX, BAC and PRO groups (p < 0.05) after 1-year water storage.

CONCLUSIONS

Compared to the control, the phosphoric acid etchants which contained protease inhibitors (CHX, BAC and PA) promoted the stability of composite-dentin microtensile bond strength and showed less nanoleakage after 1 year of water storage. They represent an effective way of prolonging the stability of the composite-dentin bonds without creating an additional bonding step.

Simvastatin modulates gingival cytokine and MMP production in a rat model of ligature-induced periodontitis

Purpose

The aim of this study was to evaluate the effect of simvastatin on the synthesis of cytokines TNF-α and IL-10 and metalloproteinase (MMPs) 2 and 9 in a rat model of ligature-induced periodontitis.

Materials and methods

Twenty Wistar rats were used, and a cotton ligature was place in a subgingival position encircling the entire cervix of the first molar of the left (ipsilateral) side of the mandible. The right (contralateral) side of the mandible had no ligature placed and was used as control. After the ligature placement, animals were randomly assigned to two experimental groups (n=10): 1) rats with ligature + vehicle (saline; 10 mL/kg; orally) and 2) rats with ligature + simvastatin (25 mg/kg; orally). After 14 days of treatment, the animals were euthanized by anesthetic overdose and the gingival tissue was removed and homogenized in appropriate buffer. MMP-2 and -9 release as well as the IL-10 and TNF-α levels were detected by enzyme-linked immunosorbent assay. Statistical comparison was performed by unpaired Student’s t-test, with p<0.05 representing significance.

Results

No differences were observed for TNF-α production between the groups (p>0.05). However, IL-10 was upregulated in simvastatin-treated animals (1.8-fold increase) in comparison with the vehicle-treated group (p<0.05). Simvastatin reduced the gingival levels of MMP-9 (64.3%) in comparison with vehicle-treated samples (p<0.05).

Conclusion

Oral treatment with simvastatin increased the release of IL-10 and reduced the MMP-9 in ligature-induced periodontitis model in rats.

Treatment Protocol for Dentin Hypersensitivity

How to cite this article

Escalante-Otárola W, Castro-Núñez G, Jordão-Basso KCF, Lima SL, Kuga MC, Bandeca MC. Treatment Protocol for Dentin Hypersensitivity. World J Dent 2017;8(1):1-4.

Five-year Effects of Chlorhexidine on the In Vitro Durability of Resin/Dentin Interfaces

PURPOSE

To evaluate the effect of an acid containing 2% chlorhexidine (Ac/CHX) or a 2% CHX aqueous solution (Aq/CHX) on the immediate and 5-year bonding properties of resin/dentin interfaces produced by two adhesives. The presence of CHX in these interfaces was also evaluated under micro-Raman spectroscopy.

MATERIALS AND METHODS

Forty-two molars were ground to expose a flat dentin surface. In the control group, the surfaces were etched with conventional phosphoric acid, and Prime&Bond NT (PB) and Adper Single Bond 2 (SB) were applied. In Ac/CHX, an acid containing 2% CHX was applied after adhesive application. In the Aq/CHX group, an aqueous solution of 2% CHX was applied for 60 s after etching. After placing the restoration, specimens were prepared and tested using the microtensile bond strength test (μTBS, 0.5 mm/min) immediately or after 5 years. For nanoleakage (NL), specimens at each period were immersed in silver nitrate solution and examined by EDX-SEM. In addition, specimens at each period underwent examination for CHX using micro-Raman spectroscopy. Data were submitted to appropriate statistical analysis (a=0.05).

RESULTS

After 5 years, NL was more pronounced in the control than in the Ac/CHX or Aq/CHX (p<0.001). Significant reductions in the μTBS were observed for all groups; however, they were more pronounced for the control (p<0.001). CHX was still present in the hybrid layers Ac/CHX or Aq/CHX groups after 5 years.

CONCLUSION

The use of a 2% chlorhexidine-containing acid or the application of an aqueous CHX primer may increase the long-term stability of resin/dentin interfaces.

Association between Tooth Loss and Degree of Temporomandibular Disorders: A Comparative Study

OBJECTIVE

The aim of this study was to evaluate the association between tooth loss and the signs and symptoms of temporomandibular disorders (TMDs).

MATERIALS AND METHODS

One hundred fifty patients with an average age of 49.2 (±14.06) years were divided into three groups (n = 50/group) according to the degree of tooth loss: GI (dentate -control), GII (edentulous), GIII (partially dentate). After performing anamnesis and clinical examination, a questionnaire was used, so that the patients could fill in information on signs and symptoms of TMD. After analyzing this information, it was possible to classify the degree of severity of TMD. As age is a confounding variable to the level of TMD, an analysis of covariance (ANCOVA) was used to check for differences in the degree of TMD between groups (covariate = age). A post hoc test (Bonferroni) was performed to compare the groups two by two (5% significance level).

RESULTS

The mean level of TMD according to the groups was GI - 1.95; GII - 2.15; GIII - 2.55. There were significant differences between the study groups (p > 0.05). A post hoc test (Bonferroni) confirmed the difference between edentulous patients and the other groups.

CONCLUSION

The tooth loss is directly related to the signs and symptoms of TMD. The degree of TMD was significantly higher in edentulous patients.

Modified Segmental Osteotomy for Relocation of Malpositioned Implant: Case Report

Obtaining a good cosmetic and proper mastication in oral rehabilitation with dental implants are directly linked to the correct positioning of the implant in the alveolar bone. The malposition of the implant is a challenge in rehabilitation, which can often compromise the entire process. In cases of severely malpositioned implants, one has the option to remove it or leave it submerged under bone and gums. Another option is the modified segmental osteotomy that aims repositioning osseointegrated implant with the surrounding bone. The objective of this case report is to present a case where an implant was severely malpositioned after surgically assisted rapid maxillary expansion, requiring a modified segmental osteotomy technique to reposition it.

Effectiveness of Oral Antiseptics on Tooth Biofilm: A Study in vivo

AIM

To evaluate the effectiveness of five different mouthwashes through measurement of the plaque index.

MATERIALS AND METHODS

Fifty subjects took part in this blind study, randomized into blocks of five groups according to the active ingredient of the mouthwash: CHX group (0.12% chlorhexidine gluconate), essential oils (EO) group, cetylpyridinium chloride (CPC) group, Tri group (triclosan) and Hamamelis virginiana (HV) group. All subjects were evaluated for a reduction in the bacterial plaque index at 7, 14 and 21 days.

RESULTS

There was a significant reduction in the mean plaque index during the period of evaluation (p < 0.01), and the reduction during the period of evaluation was different between mouthwashes (p < 0.01). The reduction in the plaque index at the end of 21 days was, in decreasing order, CHX > EO > CPC > Tri > HV.

CONCLUSION

The reduction in the plaque index during the period of evaluation was different between the types of mouth-wash. The mouthwash containing the active ingredient chlorhexidine was the most effective, followed by the essential oil, cetylpyridinium chloride, triclosan and H. virginiana.

Influence of Relining Post on the Bond Strength of Resin Cements

This study evaluated the influence of relining fiber posts on the bond strength (BS) of resin cements in the root canal. Forty bovine teeth were divided in four groups (n = 10): G1 (ARC)-fiber post cemented with resin cement RelyX ARC; G2 (ARC+Z350)-relined fiber post cemented with RelyX ARC; G3 (U200)-fiber post cemented with self-adhesive cement RelyX U200; G4 (U200+Z350)-relined fiber post cemented with RelyX U200. The roots were sectioned in six 1.2-mm slices and the push-out test was performed. Data were analyzed by three-way analysis of variance (ANOVA), and Tukey's test (a = 0.05). For the conventional resin cement, there was no significant difference between groups G1-ARC (15.5 ± 3.8) and G2-ARC+Z350 (16.1 ± 4.5). For the self-adhesive cement, the results revealed higher BS values for relined posts G4-U200 + Z350 (19.9 ± 7.9) as compared to non-relined posts G3-U200 (14.4 ± 4.5). For both cements, in groups of relined posts, the apical and the cervical thirds presented similar BS. Relining enhances the performance of the self-adhesive resin cement, and the interaction between relining and root third influences the BS to the conventional resin cement.

Nd:YAG Laser to obtain Irregularities on the Inner Surface of Porcelain

AIM

The aim of this study was to evaluate the inner surface of two ceramic systems: IPS Empress II (Ivoclar Vivadent, Germany) and In-Ceram Alumina (Vita Zahnfabrick, Germany) submitted to surface treatments, especially by Nd:YAG laser.

MATERIALS AND METHODS

Fifty samples were prepared in pellet form for each ceramic system according to manufacturers' specifications. The samples were stored at room temperature and then be subjected to surface treatment: without treatment (T0) (control), hydrofluoric acid-etched (T1), hydrofluoric acid-etched associated with the airborne particle-abraded (T2); CoJet system (T3), Nd:YAG laser (T4). The data were performed the statistical analysis by ANOVA and Tukey's test (p < 0.001).

RESULTS

The group control (T0) of the ceramics, the analysis showed the lowest roughness values; for the System Alumina In-Ceram, treatment with hydrofluoric acid (T1), associated with hydrofluoric acid and airborne particle-abraded (T2) and Nd:YAG laser (T4), had no statistically significant difference, whereas for the IPS Empress System II treatment with hydrofluoric acid (T1) and hydrofluoric acid associated with airborne particle-abraded (T2), had no statistically significant difference between the system and also CoJet (T3) and hydrofluoric acid associated with the airborne particle-abraded (T2). Photomicrographs of scanning electron microscopy showed different characteristics to the treatments for each ceramic system.

CONCLUSION

The IPS Empress II had the appearance of favoring the retention when treated with hydrofluoric acid, as well as its association with the airborne particle-abraded. Uncertainty in Alumina, treatment with hydrofluoric acid associated with the airborne particle-abraded and CoJet system and provided a surface with irregularities. With respect to the laser further studies should be performed for parameters that are ideal for your application.

CLINICAL RELEVANCE

The ceramic restorations are attractive due of their excellent esthetics and the ability to stay for long periods. However, the retention of ceramic requires further study.

Effect of repeated sterilization cycles on the physical properties of scaling instruments: a scanning electron microscopy study

BACKGROUND

Repeated sterilizations cycles cause undesirable alterations in the material properties of the instruments, such as corrosion, alterations in the hardness of the metal and the loss of the cutting sharpness of the instrument. This research examined the effect of repeated dry heat sterilization and autoclaves cycles on carbon steel (CS) and stainless steel (SS) curettes during the scaling and root planning.

MATERIALS AND METHODS

A total of 77 Gracey curettes were used in this study. Of these, 35 were SS and 42 were CS curettes submitted in different process: Dry heat, autoclave, inhibition of corrosion and autoclave, scaling, root planning and dry heat, scaling, root planning, inhibition of corrosion and autoclave. The inhibition of corrosion used on the carbon curettes (prior to sterilization in the autoclave) was sodium nitrite at 2%. The curettes received 10 consecutive cycles of sterilization and after that the cutting edges were examined in the electronic microscope, at 60 and 100 magnification times.

RESULTS

The images were evaluated by three independent examiners, who compared the photographs of each group with the control group.

CONCLUSION

The surface corrosion products and a deterioration of the edges were observed and the results showed that the SS curettes suffered little alteration with sterilization, scaling, root planning whereas the CS curettes were visibly affected by sterilization in the autoclave, but when the inhibition of corrosion was used prior to the sterilization, the oxidation was considerably reduced.

Can Whitening Strips interfere with the Bond Strength of Composite Resins?

AIM

The aim of this study was to investigate in vitro the bond strength of composite resins on enamel previously treated with whitening strips.

MATERIALS AND METHODS

A total of 48 bovine incisors were allocated to four experimental groups (n = 12 each): G1 (WSC)- treated with 9.5% hydrogen peroxide whitening strips (3D White Whitestrips® Advanced Vivid/CREST); G2 (WSO)-treated with 10% hydrogen peroxide whitening strips (3D WhiteTM/Oral B); G3 (WG)-treated with 7.5% hydrogen peroxide gel with fluorine, calcium and potassium nitrate (White Class®/FGM); and G4 (C)-control not subjected to bleaching treatment. The specimens were subjected to bleaching over 2 weeks following the manufacturers' instructions. Following the elaboration of the composite resin test specimens, the samples were stored in artificial saliva and subsequently subjected to the micro-shear test using the universal testing machine (EMIC®). The bond strength values were analyzed by one-way ANOVA and Tukey's statistical test (5%).

RESULTS

Significant differences were observed among the investigated groups (p < 0.05). The G3-WG exhibited greater values compared with the control group and the groups treated with strips, G1-WSC and G2-WSO. Analysis of the bond interface revealed that a large fraction of the failures occurred at the enamel-resin interface.

CONCLUSION

The bond strength decreased following 14 days of treatment with bleaching strips, whereas the whitening gel with 7.5% hydrogen peroxide, calcium and fluorine increased the bond strength.

Sealing ability of root-end filling materials

BACKGROUND

The aim of this research was to compare the apical sealing ability of different root-end filling materials (SuperEBA(®), ProRoot MTA(®), thermoplasticized gutta-percha + AH-Plus(®), thermoplasticized RealSeal(®)), by means of microbial indicators.

MATERIALS AND METHODS

Thus, 50 human single-rooted teeth were employed, which were shaped until size 5 0, retro - prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber-where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart influsion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance.

RESULTS

The results showed microbial leakage at least in some specimens in all of the groups. RealSeal(®) has more microbial leakage, statistically significant, compared to ProRoot(®) MTA and SuperEBA(®). No significant differences were observed when compared ProRoot(®) MTA and SuperEBA(®). The gutta-percha + AH Plus results showed no statistically significant differences when compared with the other groups.

CONCLUSIONS

All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration.

Detection of Procedural Errors during Root Canal Instrumentation using Cone Beam Computed Tomography

BACKGROUND

This study investigated procedural errors made during root canal preparation with nickel-titanium (NiTi) instruments, using cone beam computed tomography (CBCT) imaging method.

MATERIALS AND METHODS

A total of 100 human mandibular molars were divided into five groups (n = 20) according to the NiTi system used for root canal preparation: Group 1 - BioRaCe, Group 2 - K3, Group 3 - ProTaper, Group 4 - Mtwo and Group 5 - Hero Shaper. CBCT images were obtained to detect procedural errors made during root canal preparation. Two examiners evaluated the presence or absence of fractured instruments, perforations, and canal transportations. Chi-square test was used for statistical analyzes. The significance level was set at a=5%.

RESULTS

In a total of 300 prepared root canals, 43 (14.33%) procedural errors were detected. Perforation was the procedural errors most commonly observed (58.14%). Most of the procedural errors were observed in the mesiobuccal root canal (48.84%). In the analysis of procedural errors, there was a significant difference (P < 0.05) between the groups of NiTi instruments. The root canals instrumented with BioRaCe had significantly less procedural errors.

CONCLUSIONS

CBCT permitted the detection of procedural errors during root canal preparation. The frequency of procedural errors was low when root canals preparation was accomplished with BioRaCe system.

The Effect of Self-adhesive and Self-etching Resin Cements on the Bond Strength of Nonmetallic Posts in Different Root Thirds

PURPOSE

The purpose of this study was to evaluate the effect of self-adhesive and self-etching resin cements on the bond strength of nonmetallic posts in different root regions.

MATERIALS AND METHODS

Sixty single-rooted human teeth were decoronated, endodontically treated, post-space prepared, and divided into six groups. Glass-fiber (GF) posts (Exacto, Angelus) and fiber-reinforced composite (FRC) posts (EverStick, StickTeck) were cemented with self-adhesive resin cement (Breeze) (SA) (Pentral Clinical) and self-etching resin cement (Panavia-F) (SE) (Kuraray). Six 1-mm-thick rods were obtained from the cervical (C), middle (M), and apical (A) regions of the roots. The specimens were then subjected to microtensile testing in a special machine (BISCO; Schaumburg, IL, USA) at a crosshead speed of 0.5 mm/min. Microtensile bond strength data were analyzed with two-way ANOVA and Tukey's tests.

RESULTS

Means (and SD) of the MPa were: GF/SA/C: 14.32 (2.84), GF/SA/M: 10.69 (2.72), GF/SA/A: 6.77 (2.17), GF/SE/C: 11.56 (4.13), GF/SE/M: 6.49 (2.54), GF/SE/A: 3.60 (1.29), FRC/SA/C: 16.89 (2.66), FRC/SA/M: 13.18 (2.19), FRC/SA/A: 8.45 (1.77), FRC/SE/C: 13.69 (3.26), FRC/SE/M: 9.58 (2.23), FRC/SE/A: 5.62 (2.12). The difference among the regions was statistically significant for all groups (p < 0.05). The self-adhesive resin cement showed better results than the self-etching resin cement when compared to each post (p < 0.05). No statistically significant differences in bond strengths of the resin cements when comparable to each post (p > 0.05).

CONCLUSION

The bond strength values were significantly affected by the resin cement and the highest values were found for self-adhesive resin cement.

Chemical and structural characterization of glass ionomer cements indicated for atraumatic restorative treatment

Glass ionomer cements (GICs) are restorative materials, which clinical use has increased significantly during the last decade. The aim of the present study was to analyze the chemical constitution and surface morphology of four glass ionomer cements: Maxxion R, VitroFill, Vidrion R and Vitremer. Twelve polyethylene tubes with an internal diameter of 3 and 3 mm in length were prepared, filled and then transferred to a chamber with 95% relative humidity and a temperature of 37°C. The surface morphology of the tested materials was examined by scanning electron microscopy (SEM) and main components were investigated by energy-dispersive X-ray microanalysis (EDX). Scanning electron microscopy revealed irregular and rough external surface. Cracking was not observed. The main constituents were found to be aluminum, silicon, calcium, sodium and fluoride. Phosphorus, sulfur and barium were only observed in Vidrion R, while chlorine were only observed in Maxxion R. Elemental mapping of the outer surface revealed high concentration of aluminum and silicon. Significant irregularities on the surface of the tested materials were observed. The chemical constitution of all GIC was similar.

Effect of chronic stress on ligature-induced periodontitis in inbred and noninbred rats: a radiographic study

AIM

The aim was to compare the effect of chronic stress on ligature-induced periodontitis in inbred and noninbred female rats by means of a radiographic study.

MATERIALS AND METHODS

Adult Lewis (inbred) and Wistar (non-inbred) rats were used and divided into the following groups: Ligature/Stress Lewis Group (LSLG, n = 8); Ligature/Stress Wistar Group (LSWG, n = 8); Ligature Lewis Group (LLG, n = 8) and Ligature Wistar Group (LWG, n = 8). The animals were anesthetized and a silk thread was continuously kept around their second upper right molar. Then, groups LSLG and LSWG were subjected to physical stress test (physical restraint for 12 hours). After 15 days of ligature placement, the animals were euthanized. The right hemimaxilla was kept in formalin solution for 48 hours. Radiographs of the hemimaxillae were obtained using the parallelism technique and subsequently submitted to a standardized radiographic processing. The examiner was blinded to the groups and calibrated. The bone height level was measured and the data were subjected to statistical analysis (ANOVA, Tukey, p < 0.05).

RESULTS

LSWG showed bone destruction significantly higher than that of LSLG (32.1 ± 1.45 mm and 23.6 mm ± 2.13, respectively). Similarly, LWG showed bone destruction significantly higher than that of LLG (28.6 ± 1.18 mm and 25.2 ± 2.76 mm, respectively).

CONCLUSION

Inbred rats (Lewis) are less susceptible to the effects of chronic stress than are noninbred rats (Wistar) in relation to ligature-induced periodontitis.

CLINICAL SIGNIFICANCE

Epidemiological studies have shown a relationship between stress and periodontitis. One of the major difficulties of this type of research is the bias of the exact diagnosis of the patient's emotional state. Inbred lines animals have standards-specific neuroendocrine, this allows answers about the susceptibility of periodontal disease, making knowledge applicable in future clinical trials.

Atraumatic extraction, implant placement and immediate provisionalization

Front tooth extraction typically results in significant loss of hard and soft tissue volume, both in the vestibular-lingual and mesiodistal directions. As these changes can compromise the esthetic results of prosthetic rehabilitation, extraction techniques that cause minimal trauma to the remnant tissues are applied in combination with immediate implant placement to minimize such alterations. The case reported in the present article illustrates a therapeutic plan consisting of atraumatic extraction followed by immediate implant placement and provisionalization. When carefully indicated and planned, our results indicate that this technique may provide promising immediate results relative to the maintenance and stability of the peri-implanted tissues.

The prestretching effect on the force decay of orthodontic elastic chain

This in vitro study evaluated the Influence of prestretching, in the force decay of orthodontic elastic chains, at three time intervals: 2, 7 and 30 days with the brands Morelli, Orthometric and American Orthodontics. In the experimental group, prestretching was performed, stretching the elastics to increase them by 50% of their original length three times in a quick and sequential mode. All of the elastic chains were kept stretched and stored in artificial saliva at 37°C until the time of force measurement. For comparisons between the control and experimental groups, the Mann-Whitney test was used. For comparisons between time points and brands, the Kruskal-Wallis test was used, and for multiple comparisons, Miller's post-hoc test was used. The results showed statistically significant differences among the different commercial brands tested at the initial time point. The mean force at the initial time point ranged from 2.57 to 3.17 N. By day 2, the force values were between 0.97 and 1.49 N; by day 7, the values were 0.56 and 0.94 N. By day 30, the force values ranged between 0.27 and 0.66 N. We concluded that performing and duration of prestretching and the brand all Influenced the force decay of orthodontic elastic chains. Time had a greater Influence on the decay of the elastics than brand or prestretching.

Comparative analysis of physicochemical properties of root perforation sealer materials

Objectives

This study evaluated the solubility, dimensional alteration, pH, electrical conductivity, and radiopacity of root perforation sealer materials.

Materials and Methods

For the pH test, the samples were immersed in distilled water for different periods of time. Then, the samples were retained in plastic recipients, and the electrical conductivity of the solution was measured. The solubility, dimensional alteration, and radiopacity properties were evaluated according to Specification No. 57 of the American National Standards Institute/American Dental Association (ANSI/ADA). Statistical analyses were carried out using analysis of variance (ANOVA) and Tukey's test at a significance level of 5%. When the sample distribution was not normal, a nonparametric ANOVA was performed with a Kruskal-Wallis test (α = 0.05).

Results

The results showed that white structural Portland cement (PC) had the highest solubility, while mineral trioxide aggregate (MTA)-based cements, ProRoot MTA (Dentsply-Tulsa Dental) and MTA BIO (Ângelus Ind. Prod.), had the lowest values. MTA BIO showed the lowest dimensional alteration values and white PC presented the highest values. No differences among the tested materials were observed in the the pH and electrical conductivity analyses. Only the MTA-based cements met the ANSI/ADA recommendations regarding radiopacity, overcoming the three steps of the aluminum step wedge.

Conclusions

On the basis of these results, we concluded that the values of solubility and dimensional alteration of the materials were in accordance with the ANSI/ADA specifications. PCs did not fulfill the ANSI/ADA requirements regarding radiopacity. No differences were observed among the materials with respect to the pH and electrical conductivity analyses.

An harmonic smile resulted from the use of ceramic prosthesis with zirconia structure: a case report

The rehabilitation of patients requiring an esthetic smile demands a multidisciplinary approach. This clinical report describes a treatment plan for recovery aesthetics' smile of anterior teeth using ceramic prosthesis with zirconia structure. Initially, a review of aesthetic parameters, diagnostic waxing, mock-up and provisional restorations was performed. A contextual assessment of aesthetic, proportion and shape of teeth was done to recreate a natural looking for teeth in consonance with the smile line. Subsequently, based on these parameters, fixed prostheses of the upper anterior teeth using ceramic restorations with zirconia infrastructures were performed. The use of ceramic restorations with zirconia structures associated with a careful treatment plan allows the professional to integrate esthetic and function for satisfactory clinical results. How to cite the article: Tavarez RR, Gonçalves LM, Dias AP, Dias AC, Malheiros AS, Silva AC, Bandeca MC. An harmonic smile resulted from the use of ceramic prosthesis with zirconia structure: A case report. J Int Oral Health 2014;6(3):90-2.

Tecidual reaction of calcium hydroxide front chronic stress histological study in rats

BACKGROUND

The Calcium Hydroxide has been widely used as an intracanal dressing and in combination with restorative and endodontic materials and its main goal is the tissue reparation. However, when the patient has chronic stress, the immunological response and tissue repair decreases in both the epithelial and connective tissue. Therefore, the aim was to analyze the effect of chronic stress on the tissue response in rats exposed to calcium hydroxide (CH).

MATERIALS AND METHODS

A total of 60 wistar rats were anesthetized, and a polyethylene tube containing CH was inserted under the skin. After 24 h, they were divided into two groups: Calcium hydroxide + stress (CHSG) n = 30 and calcium hydroxide (CHG) n = 30. They were stressed by physical restraint, for 12 h each day for periods of 7, 15 and 30 days when 10 animals from each group were euthanized. The tissues surrounding the polyethylene tubes were removed, and slides were prepared and stained with hematoxylin and eosin. The analysis was performed with an optical microscope with magnification of 4-400 times by a blinded senior examiner. The sample slides were classified according to the following scores 0 - absent/1 - present/2 - infiltrate to: Inflammatory infiltrate containing fibrous condensation, lymphocytes, plasmacytes, macrophages, neutrophils, and eosinophils. The data were statistically analyzed using the Student's t-test (P < 0.05) for paired samples.

RESULTS

The exposure time of 7 days elicited no statistical difference between groups (P > 0.05). The 15 days exposure group had higher averages for CHG to eosinophils and inflammatory infiltrate (P < 0.05). In 30 days, CHG showed higher averages to inflammatory infiltrate and lower averages to FC (P < 0.05).

CONCLUSIONS

Some modified patterns of responses in the CHSG were observed at 15 days and 30 days.

Surgical treatment of class II malocclusion in the orthodontic boundaries: a case report

The aim of this study was to report a clinical case of treatment of Class II division I malocclusion with facial aesthetic impairment, whose therapeutic approach comprised the association of orthodontic treatment with orthognathic surgery. The treatment for the present case consisted of decompensation oflower incisors and extraction oftwo lower premolars, in order to obtain horizontal discrepancy allowing the surgery for mandibular advancement. At the end of treatment, we could clinically observe a Class I molar/canine relationship, normal overbite and overjet, presence of lip seal, type I facial profile with considerable aesthetic improvement. We can conclude that the ortho-surgical treatment is a therapeutic alternative providing the best prognosis in terms of aesthetic correction in patients with unpleasant facial profile.

Unusual solitary neurofibroma on the lower lip of a child

Neurofibromas (NF) are benign tumors with involvement of the peripheral nerve, which is not frequently located in the oral cavity, and especially, extraordinary rarity on lower lip of a child. This report describes a case of a NF on lower lip in a 12-year-old Brazilian child. NF consists of a wide variety of cell types, including Schwann cells, perineurial cells, and fibroblasts. Due to cellular heterogeneity, several hypotheses have been proposed to explain the histogenesis of this lesion. One of them, it support an origin of Schwannian, while others emphasize the participation of both Schwann cells and perineural cells. Excisional biopsy was performed to establish definitive diagnosis. Microscopically, the lesion was composed of interlacing bundles of elongated cells with wavy nuclei and small nerve fibers. Immunohistopathologic assessment showed cells positive for S-100, confirming the diagnosis of NF. No recurrence was observed after 1-year follow-up. Pediatric dentists must have a thorough knowledge of this unusual lesion.

Long-term surface hardness and monomer conversion of a nanoflled and a microhybrid composite resin

OBJECTIVE

This study aims to evaluate the degree of conversion (DC) and hydrolytic degradation through the Vickers hardness test (HV) of a nanoflled (Filtek(TM) Z-250, 3M) and a microhybrid (Filtek(TM)Supreme-XT, 3M) composite resin.

MATERIALS AND METHODS

Eight disk-shaped specimens (4 mm diameter × 2 mm thick, ISO 4049) of each material were prepared for each test. Composites were inserted into single increment in a metallic matrix and light-cured for 40 seconds. VH readings were performed for each specimen at predetermined intervals: immediately after polymerization (control), 1, 2, 3, 7, 14, 21, 30 and 180 days. After curing, initial hardness measurements were performed and the specimens were immersed in artifcial saliva at 37°C. For DC (%), specimens were ground, pressed with KBr and analyzed by FT-IR spectrophotometer.

RESULTS

Student t-test showed that there was no difference between the resins for DC (p = 0.252). ANOVA analysis revealed that Z-250 VH means were all greater than S-XT, for both top and bottom surfaces, whatever the storage-period in artifcial saliva (p < 0.001). After 180 days of storage, the hardness obtained for S-XT was similar with that at the baseline, for both top and bottom surfaces. While for Z-250 hardness was not signifcantly different from baseline only for top surface, but there was a signifcant decrease observed in hardness for bottom surface.

CONCLUSION

The materials tested showed no evidence of hydrolytic degradation in a signifcant way, in a 6-month storage-time in artifcial saliva. Nanoflled resin presents a monomer conversion comparable to the conventional microhybrid.

Cleft lip and palate in a Brazilian subpopulation

BACKGROUND

This work aimed to access the profile of cleft lip and palate patients of a sub-population in Mid-West Brazil.

MATERIALS & METHODS

Research was carried out through a cross-sectional study at the Craniofacial Rehabilitation Center of the University General Hospital of the University of Cuiabá, Mato Grosso, Brazil. Variables related to oral cleft type, gender, race, age and presence or absence of associated congenital anomalies or syndromes were analyzed.

RESULTS

313 patients treated at the institution from 2004 to 2007 were recruited. There were 54% male and 46% female patients with the mean age of 11.4 years. Cleft lip and palate was the most prevalent alteration in 49.6% of cases. Caucasians were the most affected in 54.6% of cases. 6.4% of patients had other anomalies or syndromes associated with cleft.

CONCLUSION

More comprehensive surveys should be conducted in order to supply the lack of data on the occurrence and determinants of oral clefts in this region. How to cite this article:Cuozzo FD, Espinosa MM, Serafim da Silva KT, Martins de Barros YB, Bandeca MC, Aranha AM, Borges AH, Volpato LE. Cleft lip and palate in a Brazilian subpopulation. J Int Oral Health 2013; 5(4):15-20.

Lipid Profile Parameters under influence of Periodontitis Associated with Chronic Stress: An Animal Model Study

BACKGROUND

The present study compared the effect of two chronic stress models associated with periodontitis induced in rats on partial lipid profile parameters.

MATERIALS & METHODS

Forty-eight rats were divided into 4 groups: physical stress+periodontitis, variable stress+periodontitis, periodontitis and control. Physical stress and variable stress occurred over 60 days. After the first ten days of the stress test, periodontitis was induced by ligature. After 60 days of experimentation, the animals underwent incision and visualization of the posterior vena cava, and blood punctures were performed under a vacuum. Impartial and trained examiners performed the analysis of the parameters: low-density lipoprotein, high density lipoprotein, triglycerides and cholesterol.

RESULTS

The lipid parameters and cholesterol were significantly lower in the variable stress group than in the ligature and control groups. The physical stress group was not statistically different from the other groups. The triglyceride level was highest for the control group and statistically different from the levels in groups variable stress and physical stress. The physical stress group had the lowest triglyceride level, which was statistically different from that of the control group. There was no statistical difference between physical stress and variable stress with respect to low-density lipoprotein; a similar finding was obtained for ligature and control. The variable stress group had the lowest low-density lipoprotein level, which was statistically different from those of the ligature and control groups. High density lipoprotein levels showed no statistical differences between groups.

CONCLUSION

Despite the limitations of the methodology, it seems that the stress model variable associated with periodontitis improved lipid parameters in the study. How to cite this article:Porto AN, Borges AH, Segundo AS, Semenoff TA, Pedro FL, Bandeca MC, Cortelli SC. Lipid profile parameters under influence of periodontitis associated with chronic stress: an animal model study. J Int Oral Health 2013; 5(4):8-14.

When and Why Parents Seek Dental Care for Children under 36 Months

BACKGROUND

The aim was to analyze an infant preventive program determining at what age parents take their children for their first dental visit and the reasons why they do it.

MATERIALS & METHODS

A total of 844 children aged from 0 to 36 months, enrolled in the program of oral health maintenance of the Baby Clinic, participated in this study. During the first dental visit, the parents were inquired about the reasons that led them to enroll their children in the program. One trained investigator identified this reasons on the records and classified them according to the following scores: orientation/prevention, caries treatment, malpositioned teeth, dental trauma, tooth color alterations and others.

RESULTS

Orientation/prevention was the most prevalent reason from 0-6 months to 25-30 months of age, and at the age 30-36 months, the reason caries/treatment overcame orientation/prevention, becoming the most prevalent reason in that age group. The third place was occupied by dental trauma. The mean age parents seek for dental care to their children was 14, 92 months.

CONCLUSION

This study showed a preferentially preventive/educational profile for the children. However, lots of parents still take children to the dentist preferentially for curative instead of preventive treatment. How to cite this article: Volpato LE, Palti DG, Lima JE, Machado MA, Aranha AM, Bandeca MC, Pedro FL, Borges AH. When and Why Parents Seek Dental Care for Children under 36 Months. J Int Oral Health 2013; 5(4):21-25.

Animal bite injuries to the face : A Case Report

Traumatic lacerations to the skin are problems frequently seen and treated by emergency centers around the world. Among all wounds, dog and cat bites are commonly seen. As in many mammals, different species of microorganisms are found in dog and cat mouths with a potential pathological effect to humans, as represented by rabies. The injuries have disfiguration effect with possible psychological repercussion to the patient. This article aimed presenting up to date considerations regarding the management of animal bite injuries to the face, exemplified by a case report that should be the interest of all professions that deal with facial tissues, as dentists do. How to cite this article: Simao NR, Borba AM, da Silva ALF, Vieira EMM, Carvalhosa AA, Bandeca MC, Borges AH. Animal bite injuries to the face: A Case Report. J Int Oral Health 2013; 5(4):68-72.