Abstract This study was a randomized controlled clinical trial with two parallel arms and the objective was to compare the survival of resin modified glass ionomer (RMGIC) restorations in primary teeth using rubber dam or cotton roll isolation after a 30-month follow-up period. Ninety-two children (mean age 6.8 ± 1.37) and 200 primary molars with occlusal or occluso-proximal cavitated dentin caries lesions were randomly assigned into two groups: cotton rolls and rubber dam. All lesions were restored using RMGIC (RIVA Light Cure) after selective caries removal. Restorative failure and lesion arrestment were evaluated by two independent, trained, and calibrated examiners through clinical and radiographic examinations. The Kaplan-Meier test was used to assess the survival of restorations and Cox regression was used to assess the association of risk factors with restorative failure. There was no significant difference in survival rates between groups (p = 0.17). Older age (HR = 2.81 [95%CI: 1.47–5.44]) and higher rate of gingival bleeding (HR = 0.47 [95%CI: 0.23–0.99]) were associated with restorative failure. No patient had painful symptoms, pulp outcomes, or radiographic changes compatible with lesion progression. The use of rubber dam isolation did not increase the survival rate of occlusal and occluso-proximal restorations using RMGIC in primary molars after 30 months of follow-up. Since the survival is not influenced by the type of isolation, the professional can safely choose the appropriate technique for each case, considering his experience and preferences, as well as those of the patient. (RMGIC 30month month followup follow up period Ninetytwo Ninety mean 68 6 8 6. 1.37 137 1 37 20 occlusoproximal occluso proximal RIVA Cure removal independent trained examinations KaplanMeier Kaplan Meier p 0.17. 017 0.17 . 0 17 0.17) HR 281 2 81 2.8 95%CI 95CI CI 95 [95%CI 1.47–5.44 147544 47 5 44 1.47–5.44] 047 0.4 0.23–0.99 023099 23 99 0.23–0.99] symptoms outcomes progression 3 followup. up. case preferences 1.3 13 01 0.1 28 2. 9 1.47–5.4 14754 4 04 0. 0.23–0.9 02309 1. 1.47–5. 1475 0.23–0. 0230 1.47–5 147 0.23–0 023 1.47– 14 0.23– 02 1.47 0.23 1.4 0.2

ABSTRACT Objective: To compare the survival of occlusal and occlusal-proximal restorations performed with resin-modified glass-ionomer cement (RMGIC) in deciduous molars using rubber dam and cotton rolls isolation. Material and Methods: Ninety-two patients were included and 200 deciduous molars with cavitated occlusal or occlusoproximal dentin caries lesions were randomized into two groups: cotton rolls (n = 100) and rubber dam (n = 100) and RMGIC restorations were placed. At baseline and in the follow-up visit, presence, severity and activity of caries lesions were registered. Two independent, blinded examiners evaluated the treated teeth clinically using the USPHS criteria and radiographically after 9 months. Descriptive analysis, survival curve (log-rank test) and Cox regression were performed to assess risk factors related to failure. Results: Out of the 179 teeth (92 cotton rolls group and 87 rubber dam group) evaluated at 9-month follow-up period. No lesion progression was observed radiographically. The overall treatment success rate was 85.47% (83.47% for cotton rolls and 87.35 rubber dam group). No significant difference between isolation methods was observed in the log-rank test (p = 0.16). Cox regression showed no risk factors related to failure. Conclusion: No difference was found in the survival of occlusal and occlusal-proximal restorations performed with RMGIC in deciduous molars using a rubber dam and cotton rolls isolation after a 9-month follow-up period.

Resumo Este estudo avaliou a efetividade de modelos para o desenvolvimento de lesões de cárie subsuperficiais in vitro e verificou alterações minerais por microradiografia transversal (TMR). Blocos de esmalte de dentes permanentes (n = 5) e decíduos (n = 5) foram submetidos à indução de lesão por imersão em soluções desmineralizadoras durante 96h, seguido de ciclos de pH de desmineralização e remineralização por 10 dias. Duas soluções des-/re foram testadas. A solução desmineralizadora “A” foi composta por 2,2 mM de CaCl2, 2,2 mM de KH2PO4, 0,05 M de ácido acético, com pH de 4,4 ajustado por 1 M de KOH. A solução desmineralizadora “B” foi composta por 2,2 mM de CaCl2, 2,2 mM de NaH2PO4, 0,05 M de ácido acético e 0,25 ppmF, com pH de 4,5 ajustado por 1 M de KOH. A solução “A” produziu lesões cavitadas em dentes permanentes, enquanto a solução “B” apresentou lesões subsuperficiais em dentes decíduos. Portanto, a solução “B” foi posteriormente usada em blocos de esmalte de dentes permanentes (n = 5) e lesões subsuperficiais foram obtidas. Portanto, a solução “B” foi empregada para ambos os substratos, sendo metade deles tratada com dentifrício fluoretado e a outra metade com dentifrício livre de flúor. A solução “B” produziu lesões subsuperficiais de cárie com profundidade de 88.4µm (14.3) em dentes permanentes e com 89.3 µm (15.8) em dentes decíduos e TMR demonstrou que lesões tratadas com dentifrício sem flúor tiveram maior perda mineral. Este estudo concluiu que a solução “B” desenvolveu lesões subsuperficiais após o ciclo de pH e as alterações minerais foram avaliadas com sucesso por TMR.

Abstract This study assessed the effectiveness of models for developing subsurface caries lesions in vitro and verified mineral changes by transverse microradiography (TMR). Enamel blocks from permanent (n=5) and deciduous teeth (n=5) were submitted to lesion induction by immersion in demineralizing solutions during 96 h, followed by pH cycles of demineralization (de) and remineralization (re) for 10 days. Two de-/re solutions were tested. Demineralizing solution “A” was composed by 2.2 mM CaCl2, 2.2 mM KH2PO4, 0.05 M acetic acid, with pH 4.4 adjusted by 1 M KOH. Demineralizing solution “B” was composed by 2.2 mM CaCl2, 2.2 mM NaH2PO4, 0.05 M acetic acid and 0.25 ppmF, with pH 4.5 adjusted by 1M KOH. Solution “A” produced cavitated lesions in permanent teeth, whereas solution “B” led to subsurface lesions in deciduous teeth. Solution “B” was then tested in enamel blocks from permanent teeth (n=5) and subsurface lesions were obtained, so that solution “B” was employed for both substrates, and the blocks were treated with slurries of a fluoride dentifrice (1450 ppm F, as NaF, n=5) or a fluoride-free dentifrice (n=5). Solution “B” produced subsurface lesions in permanent and primary teeth of an average (±SD) depth of 88.4µm (±14.3) and 89.3µm (±15.8), respectively. TMR analysis demonstrated that lesions treated with fluoride-free dentifrice had significantly greater mineral loss. This study concluded that solution “B” developed subsurface lesions after pH cycling, and that mineral changes were successfully assessed by TMR.

ABSTRACT Objective: To evaluate the effect of erosive challenges on the tooth- restoration interface of deciduous teeth treated with different adhesive protocols. Material and Methods: Deciduous molars were cut mesiodistally, then embedded, abraded and polished (n=80). Samples were randomly divided according to the adhesive system used into: G1 (Adper Single Bond2®, etch-and-rinse), G2 (Universal Single Bond®, self-etching), G3 (OptibondFL®, etch-and-rinse with Fluoride) and G4 (BondForce®, self-etching with Fluoride). After standardized cavity preparation (2 mm diameter x 2 mm depth), adhesive systems were applied and samples were restored (composite resin Z350®). Half of the samples were exposed to erosive/abrasive cycles (n = 10, each adhesive group), and the other half (control group; n = 10) remained immersed in artificial saliva. For microleakage analysis, samples were submersed in methylene blue and analyzed at 40x magnifications. Cross-sectional microhardness (CSMH) was carried out (50 g/5 s) at 25 μm, 50 μm, and 100 μm from the eroded surface and at 25 μm, 75 μm, and 125 μm from the enamel bond interface. Results: Regarding microleakage, 7.5% of the samples showed no dye infiltration, 30% showed dye infiltration only at the enamel interface, and 62.5% showed dye infiltration through the dentin-enamel junction, with no difference between groups (p≥0.05). No significant difference was observed in CSMH at different depths (two-way ANOVA, p≥0.05). Conclusions: We did not observe significant changes in microleakage or CSMH after erosive/abrasive challenges in deciduous teeth treated with different adhesive protocols (etch-and-rinse and self-etching adhesives, with and without fluoride).