Márcia Pereira Alves dos Santos

Randomised trial of resin-based restorations in Class I and Class II beveled preparations in primary molars: 48-Month results

OBJECTIVE This randomised clinical trial evaluated the survival rate of resin-based restorations in Class I and Class II beveled preparations in primary molars, over 48 months. METHODS Forty-eight children received 141 restorations in beveled cavosurface margin preparations in primary molars randomly assigned by a lottery method: 46 received treatment with Vitremer Tri-Cure Glass Ionomer System (33 Class I and 13 Class II restorations); 51 received treatment with Freedom (36 Class I and 15 Class II restorations); 44 received treatment with TPH Spectrum (30 Class I and 14 Class II restorations). Two calibrated examiners (weight kappa> or =0.85) evaluated the restorations using the modified USPHS criteria and visible plaque index score at baseline and after 12, 24, 36 and 48 months. Cox regression with survival analysis and logistic regression evaluated the clinical performance of restorations. RESULTS After 48 months, 11 teeth had exfoliated, 16 restorations were dropouts, 83 restorations were clinically successful of which 26 had used Vitremer, 32 had used Freedom and 25 had used TPH Spectrum. Thirty-one restorations failed because of secondary caries, fractures and loss of retention. The cumulative survival was 73.9%, 83.4% and 79.6%, respectively for Vitremer, Freedom and THP Spectrum with no differences among materials (Log Rank Mantel-Cox, p>0.05). However, the Class II cavity preparation reduced the survival of the restorations (OR=5.1) for all materials evaluated (p>0.05). CONCLUSIONS The life expectancy of Vitremer, Freedom and THP Spectrum in Class I and Class II restorations could be comparable after 48 months.

Molar Incisor Hypomineralization: Morphological, Aetiological, Epidemiological and Clinical Considerations

The prevalence of dental caries has been reduced over the years due to increased access of fluorides, such as fluoride tooth paste, to dental services and to oral health education on the great part of the population. However, a significant portion of the same population still remains undertreated and show dental cavities as after-effects of this oral disease. In spite of dental caries is strongly influenced by social, economic, cultural, religious and environmental factors, its severity may be increased by structural changes of enamel/dentin such those observed in cases of molar incisor hypomineralization (MIH). In a Brazilian survey, children with MIH showed higher caries experience in the permanent dentition than the general population of similar age. (da Costa-Silva et al., 2010) The MIH increases the dental caries risk as consequence of affected teeth because they are not only soft and porous enamel teeth but also very sensitive to stimuli making effective oral hygiene difficult. (Kilpatrick, 2009) Several aetiological factors are mentioned as the cause of MIH (Alaluusua, 2010, Lygidakis et al., 2010, Crombie et al., 2009, Brook, 2009) and they are frequently associated with childhood diseases or nutritional conditions during the first three years of life. (Fagrell et al., 2011)

Topography and presence of a smear layer in deciduous molars prepared with high-speed cutting and ultrasonic abrasion: an in-vitro study

Abstract Objective. The aim of this in-vitro study was to compare the effect of high-speed cutting (HS) with ultrasonic abrasion (US) concerning the internal topography and the presence of a smear layer in a cavity preparation performed in healthy deciduous molars. Material and methods. Seven first deciduous molars were used. Two occlusal cavity preparation were done, one in the medial fossula and another in the distal fossula, which were chosen randomly. One preparation was carried out with a diamond point adapted to the HS system (GI), while a chemical vapor deposition (CVD) point adapted to a US device (GII) was used for the other preparation. Subsequently, all samples (n = 14) were cleaved to observe the inside and then prepared for evaluation using scanning electron photomicroscopy. The internal topography of the prepared cavities was descriptively analyzed. In order to assess the presence of a smear layer, scores were tabulated using the 2000 GMC program and analyzed using the Mann–Whitney test. Results. Concerning the internal topography, the presence of striae was verified in both groups. In the GI group they were finer, found in a greater number, and with narrower spaces between them. In the GII group, the striae were undulating, similar to the effect of wheels on sand, and with wider spaces between them. As regards the presence of a smear layer, there was no statistically significant difference between the groups (P > 0.05). Conclusions. In view of the methodology employed, it may be concluded that cavity preparation with a CVD point in a US abrasion system led to the formation of fewer striae and both devices promoted the marked presence of a smear layer, obstructing dentinal tubuli.

Efeito do Bisel no Esmalte Sobre a Microinfiltração em Preparos Classe I em Molares Decíduos

Resumen pt: Objetivo: Avaliar in vitro a influencia da terminacao marginal do preparo cavitario Classe I sobre a qualidade adesiva em restauracoes compositas realiza...

Split mouth randomized controlled clinical trial of beveled cavity preparations in primary molars : an 18-Month follow up

OBJECTIVES This split-mouth, double-blind, randomized controlled study evaluated the clinical performance of composite restorations in Class I beveled margin cavity preparations in primary molars. METHODS A total of 94 Class I cavity preparations were performed in the carious primary molars of 32 children aged 4-10 years. Two cavity designs were used: conventional conservative preparation (G1) and modified preparation with cavosurface bevel (G2). All teeth were restored using TPH Spectrumtrade mark. The restorations were evaluated by two calibrated investigators at baseline, 6, 12 and 18 months using slight modified USPH criteria. The visible plaque index and fiber optic transilumination (FOTI) were also used. The data were statistically evaluated using Wilcoxon and Friedman tests (p<0.05). The rank correlations between secondary caries, visible plaque index and FOTI were obtained using Pearson correlation (p<0.01). RESULTS Of the 94 restorations performed and evaluated at baseline, 76 restorations were available after 18 months. Seventy-three restorations were considered as clinical success, 10 were censored for drop out reasons and 5 were lost by natural exfoliation. Four restorations failed by secondary caries and two failed by marginal adaptation discrepancies. For all evaluation there was difference between the baseline, 6, 12 and 18 months (p<0.05) but there were no statistically significant difference in G1 and G2 for any criteria evaluated (p>0.05) at any period of the study. The visible plaque index was correlated to secondary caries. CONCLUSION Bevel cavity design preparations did not improve the success of composite restorations in primary molars over 18 months.

Surface Degradation of Resin-based Materials by Pediatric Syrup Containing Amoxicillin under Erosive Challenge

Objective: To investigate the effect of a pediatric syrup containing Amoxicillin on resin-based on the surfaces of resin-based materials under pH cycling. Material and Methods: Cylindrical samples (n=60) of a compomer (Freedom) and a microhybrid composite (TPH Spectrum) were prepared following the manufacturer’s instructions. The specimens were divided into two groups and treated for 30min, twice a day, for 14 days with a pediatric syrup containing Amoxicillin, Amoxil™ 500mg/5ml (experimental group) or Distilled water (control group). During the 14 days, the samples were submitted to pH cycling (3h in demineralizing, 20h in remineralizing saliva, and 1h for treatment). The surface roughness was evaluated at baseline, on the 7 th and 14 th days of erosive challenge using a profilometer and illustrated by SEM. The data were statistically analyzed by one-way ANOVA, Tukey HSD and paired T- tests (p 0.05). Results: After 7 days, it was observed no erosion (p = 0.674) for THP Spectrum (0.19 Ra) and an increasing of Ra (p = 0.02) for Freedom (19.95 Ra). After 14 days, it was observed an increasing of Ra for both THP Spectrum (0.56 Ra) and for Freedom (3.44 Ra), demonstrating that the degradation was treatment and time-dependent (p < 0.001). The pediatric syrup containing Amoxicillin increased the surface roughness of the TPH Spectrum surface one and a half times (p = 0.003) and the surface roughness of Freedom was increased by more than two times (p < 0.001). SEM images showed different aspects of the surfaces of the two materials with a loss of integrity to both. Conclusion: The pediatric syrup containing Amoxicillin under pH cycling increased the roughness of the both tested resin-based restorative materials.