Rachel de Oliveira Rocha

In vivo effectiveness of laser fluorescence compared to visual inspection and radiography for the detection of occlusal caries in primary teeth.

The purpose of this study was to evaluate the in vivo effectiveness of laser fluorescence compared to visual inspection and radiography for the detection of occlusal caries in primary teeth. Fifty sites from 30 molars in 29 patients were selected and evaluated under standardized conditions by 2 previously trained examiners according to the 3 diagnostic methods. Histological examination served as gold standard after exfoliation or extraction. Values obtained for sensitivity, specificity and accuracy were 0.60, 0.90 and 0.73 for laser fluorescence, 0.82, 0.85 and 0.84 for visual inspection and 0.62, 0.73 and 0.67 for radiography, respectively. Considering only dentinal caries, values were 0.73, 0.95 and 0.90 for laser fluorescence, 0.61, 1.00 and 0.90 for visual inspection and 0.96, 0.81 and 0.85 for radiography, respectively. We conclude that for the detection of occlusal caries in primary molars laser fluorescence presents a similar accuracy when compared to visual inspection and radiography, although visual inspection showed better values for sensitivities for both enamel and dentin lesions.

Chlorhexidine does not increase immediate bond strength of etch-and-rinse adhesive to caries-affected dentin of primary and permanent teeth

The aim of this study was to evaluate the effect of 2% chlorhexidine digluconate (CHX) on immediate bond strength of etch-and-rinse adhesive to sound (SD) and caries-affected (CAD) primary dentin compared with permanent dentin. Flat dentin surfaces from 20 primary molars (Pri) and 20 permanent molars (Perm) were assigned to 8 experimental groups (n=5) according to tooth type (Pri or Perm), dentin condition (SD or CAD - pH-cycling for 14 days) and treatment (control - C or 60 s application of 2% CHX solution after acid etching - CHX). The bonding system (Adper Single Bond 2) was applied according to manufacturers instructions followed by resin composite application (Filtek Z250). After 24 h water storage, specimens with cross-section area of 0.8 mm² were prepared for being tested under microtensile test (1 mm/min). Data were submitted to ANOVA and Tukeys post hoc test (α=0.05). Failure mode was evaluated using a stereomicroscope at ×400. Treatment with CHX did not result in higher bond strength values than no pre-treatment (C groups), independently of tooth type. Primary teeth and caries-affected dentin showed significantly lower (p<0.05) bond strength means compared with permanent teeth and sound dentin, respectively. Predominance of adhesive/mixed failure was observed for all groups. CHX did not influence the immediate bond strength to sound or caries-affected dentin of primary and permanent teeth.

Degradation of resin-dentin bonds of etch-and-rinse adhesive system to primary and permanent teeth

The aim of this in vitro study was to compare the degradation of resin-dentin bonds of an etch-and-rinse adhesive system to primary and permanent teeth. Flat superficial coronal dentin surfaces from 5 primary second molars and 5 permanent third molars were etched with phosphoric acid and bonded with an adhesive system (Adper Single Bond 2, 3M ESPE). Blocks of resin composite (Z250, 3M ESPE) were built up and the teeth sectioned to produce bonded sticks with a 0.8 mm² cross-sectional area. The sticks of each tooth were randomly divided and assigned to be subjected to microtensile testing immediately (24 h) or after aging by water storage (6 months). Data were analyzed by two-way repeated measures ANOVA and Tukey post hoc test (α = 0.05). Failure mode was evaluated using a stereomicroscope (400×). Microtensile values significantly decreased after the 6 months aging, independent of the dentin substrate. In 24 h, the values obtained to primary dentin were lower compared with permanent dentin. This difference was not maintained after aging. Adhesive/mixed failure was predominant in all experimental groups. In conclusion, degradation of resin-dentin bonds of the etch-and-rinse adhesive system occurred after 6 months of water storage; however, the reduction in bond strength values was higher for permanent teeth.

Are self-etch adhesive systems effective in the retention of occlusal sealants? A systematic review and meta-analysis.

BACKGROUND Occlusal sealants are an effective method for caries prevention, although the effectiveness of different application strategies has not been established yet. AIM This systematic review compared the retention rate of sealants placed on occlusal surfaces following the use of self-etch adhesive systems and traditional acid etching, with or without the application of adhesive system. DESIGN Literature searching was carried out until June 2015 in PubMed/MEDLINE, CENTRAL, and ClinicalTrials databases selecting randomized clinical trials that evaluated self-etch adhesive systems associated with pit and fissure sealants in primary or permanent molars comprising retention as outcome. From 683 potentially eligible studies, 10 were selected for full-text analysis and 5 were included in the meta-analysis. Two reviewers independently selected the studies, extracted the data, and assessed the bias risk. Pooled-effect estimates were obtained by comparing the retention failure rate between groups (self-etch systems vs acid etching with or without adhesive systems). RESULTS Significant difference was found between groups, favoring the control group (prior acid etching) (P < 0.05), which showed lower failure rate in the retention of occlusal sealants. High heterogeneity was found on the meta-analysis. Most trials showed good evidence strength. CONCLUSIONS Occlusal sealants applied with self-etch systems show lower retention throughout time than sealants applied in the conventional approach, regardless of the use of adhesive systems.

Erosive effects of beverages in the presence or absence of caries simulation by acidogenic challenge on human primary enamel: an in vitro study

AIM: To evaluate in vitro the erosive effects of beverages in the presence or absence of caries simulation (acidogenic challenge) on the microhardness of primary enamel. METHODS: Forty human primary teeth were submitted to the erosive effects: 3×20-min-long daily immersion in fresh orange juice (orange group), strawberry yogurt drink (yog group), or cola soft drink (cola group) separately or in combination with acidogenic challenge (pH cycling for 10 days). Specimens were also submitted to acidogenic challenge alone, and in the negative control group specimens were not submitted to any treatment. Mineral loss was evaluated by cross-sectional microhardness determination. The data (Knoop hardness numbers, KHN) were subjected to 2-way analysis of variance and Tukey’s post hoc test (α = 0.05%). RESULTS: All the test beverages significantly reduced the sample cross-sectional enamel hardness (KHN ± SD, 235.93 ± 18.15, 257.23 ± 21.79, and 253.23 ± 13.86 in the orange, yog, and cola groups, espectively) compared to samples in the negative control group (290.27 ± 3.92). In vitro acidogenic challenge exacerbated the mineral loss induced by all beverages (166.02 ± 4.28,190.43 ± 17.55, and 198.39 ± 21.39 in the orange, yog, and cola groups combined to acidogenic challenge, respectively) compared to acidogenic challenge alone. CONCLUSIONS: All beverages exhibited erosive effects on primary enamel. Simulated caries challenge considerably exacerbated the enamel softening of primary teeth.

Effect of Two Microshear Test Devices on Bond Strength and Fracture Pattern in Primary Teeth

This in vitro study evaluated the influence of two devices for application of shear load in microshear tests on bond strength and fracture pattern of primary enamel and dentin. Eighty primary molars were selected and flat enamel (40 teeth sectioned mesio-distally) and dentin (40 teeth sectioned transversally) surfaces were obtained. Both surfaces were polished to standardize the smear layer. Two-step etch-and-rinse adhesive systems (Adper Single Bond and XP Bond) were used. Polyethylene tubes was placed over the bonded surfaces and filled with composite resin. The microshear testing was performed after storage in water (24 h/37 °C) using two devices for application of microshear loads: a notched rod (Bisco Shear Bond Tester) or a knife edge (Kratos Industrial Equipment). Failure modes were evaluated using a stereomicroscope. Bond strength data were subjected to ANOVA and chi-square test to compare the failure mode distributions (α=0.05). No significant differences were observed between the groups for dentin and enamel bond strength or fracture patterns (p>0.05). The predominant failure mode was adhesive/mixed. In conclusion, the devices for application of shear loads did not influence the bond strength values, regardless of adhesive system and substrate.

Is there a best conventional material for restoring posterior primary teeth? A network meta-analysis

This study aimed to compare the longevity of different conventional restorative materials placed in posterior primary teeth. This systematic review was conducted following the PRISMA statement and registered in PROSPERO (CRD42016035775). A comprehensive electronic search without date or language restrictions was performed in PubMed/MEDLINE, Cochrane Central Register of Controlled Trials, Scopus, Turning Research Into Practice (TRIP) and Clinical Trials databases up to January 2017, selecting randomized clinical trials that assessed the longevity of at least two different conventional restorative materials performed in primary molars. Seventeen studies were included in this systematic review. Pairwise and network meta-analyses were performed and relative risks and 95% confidence intervals (CI) calculated. Two reviewers independently selected the studies, extracted the data, and assessed the risk of bias. Restorations of primary molars with conventional glass ionomer cement showed increased risk of failure than compomer, resin-modified glass ionomer cement, amalgam, and composite resin. Risk of bias was low in most studies (45.38% of all items across studies). Pediatric dentists should avoid conventional glass ionomer cement for restoring primary molars.

The Thickness of the Adhesive Layer Increases the Misdiagnosing of the Radiolucent Zones and Restoration Replacement Indication

OBJECTIVE To evaluate the influence of the thickness of the adhesive layer and demineralized dentin on the decision to replace composite restoration. MATERIALS AND METHODS Eighty human third molars with occlusal preparations (Class I) were randomly assigned to eight groups (n = 10): adhesive system (Clearfil SE Bond [CSE] or Scotchbond Universal Adhesive [SBU]); the number of adhesive layers (one or two); and substrate (sound or demineralized dentin). A blinded examiner evaluated radiographs of each restored tooth. Obtained scores for the presence or absence of radiolucent zone under restoration were submitted to a relative risk (RR) calculus and Z-test, and the scores for the decision to replace restorations were submitted to Fishers exact test (p < 0.05). RESULTS The relative risk of identifying a radiolucent zone under restoration in sound and demineralized dentin were, respectively, 2 and 1.85 times higher when two layers of adhesive were applied. Demineralized dentin did not increase the probability of identifying a radiolucent zone. A higher relative (1.6, p = 0.01) was observed when two layers of SBU were applied. The number of layers did not influence the relative risk for CSE (RR = 1.3, p = 0.13). CONCLUSION Thicker layers of SBU increase the relative risk of identifying a radiolucent layer under restoration and the decision to replace a/composite restoration, irrespective of the substrate. The presence of demineralized dentin did not increase the probability of identifying a radiolucent zone when compared to sound dentin. CLINICAL SIGNIFICANCE The results of this in vitro study suggest that thicker layers of a particular adhesive under resin composite restorations can negatively influence the decision to replace them. (J Esthet Restor Dent 29:193-200, 2017).

Color stability of a resin composite: Effect of the immersion method and surface treatments

Background: In vitro staining methods expose the entire specimen to staining solutions. In a real clinical situation, this is not observed, since one should consider that the bonded surface is not exposed to the oral environment. Theoretically, the clinical condition would be the best simulated if the specimens were exposed to staining solutions by partial immersion. Aims: To evaluate if different immersion methods and surface treatments influence the color stability of resin-based specimens. Methodology: A stainless steel matrix was used to prepare 30 disc-shaped specimens that were randomly allocated in three groups: Without polishing, polishing with abrasive discs, and surface sealant. Half of the specimens were isolated to maintain only the upper surface exposed to staining (partial immersion) and the other half was totally immersed in coffee solution for 48 h (total immersion). The coordinates ΔE*, ΔL*, Δa*, Δb* were assessed by spectrophotometer. Statistical Analysis: Two-way ANOVA and Tukeys post hoc tests (α =0.05). Results: Specimens submitted to partial immersion showed lower values of ΔE*, ΔL*, Δa*, Δb*, in comparison to total immersion (P = 0.000). Specimens covered by a surface sealant presented lower ΔE* values regardless of the immersion method. Conclusions: Specimens totally immersed in staining solutions could in somehow overestimate the color change, once that in most clinical conditions not all of the restoration surfaces are exposed to the oral environment. Moreover, as the surface sealant application produces color change values that are clinically acceptable, it might be used in esthetic restorations as an adjunct treatment.

Comparison of validation methods for the diagnosis of occlusal caries in primary molars

AIM: To evaluate the reproducibility of 7 validation methods used for caries diagnosis in primary teeth. METHODS: Seventy-two occlusal sites were selected on 40 primary molars. The sites were evaluated independently by 3 experienced examiners using validation methods that involved direct assessment, i.e. by using a (1) magnifying glass (8) and (2) stereomicroscope (35), or indirect assessment i.e. by using (3) photographs, (4) slide projections of photographs, (5) stereomicroscope (35) photographs, (6) stereomicroscope (35) slide projections, and (7) projections of polarised light microscope slides. Cohen’s kappa coefficients were calculated and subjected to the Kruskal-Wallis test at a significance level of 5%. RESULTS: The mean inter-examiner kappa values for the validation methods were 0.31–0.51. There were statistically significant differences (p<0.05) between methods 1 and 3, 1 and 4, 2 and 4, 4 and 5, 4 and 6, and 4 and 7. Moderate agreement was observed for all methods except methods 1 and 4, for which the agreement was fair. CONCLUSIONS: The inter-examiner agreement for all validation methods for caries diagnosis was moderate, except for the method based on indirect assessment by slide projection, which showed low agreement.