Bilayer technique and nano-filled coating increase success of approximal ART restorations: a randomized clinical trial.

BACKGROUND: The high-viscosity consistency of glass ionomer cement (GIC) may lead to its incorrect adaptation into the cavity and therefore to restoration failure. AIM: To compare two different insertion techniques for GIC in approximal atraumatic restorative treatment (ART) restorations and two different surface protection materials. DESIGN: Approximal caries lesion in primary molars from 208 schoolchildren was randomly assigned into four groups: G1, conventional GIC insertion protected with petroleum jelly (PJ); G2, bilayer technique protected with PJ; G3 conventional GIC insertion protected with nano-filled particles coating for GIC (NPC); G4, bilayer technique protected with NPC. Restorations were evaluated after 1, 6, 12, 18, 24, and 36 months. Kaplan-Meier survival analysis and log-rank test were performed. Cox regression analysis (α = 5%) was used to verify the influence of clinical factors. RESULTS: Restoration survival was 52.8%. Log-rank test indicated a better survival of the bilayer technique restorations, compared to conventional restorations (P = 0.005), whereas the coated conventional restorations presented higher survival than the uncoated ones (P = 0.035). Cox regression analysis showed no influence of any clinical tested variables. CONCLUSION: The survival rate of the approximal ART restorations is positively influenced by the bilayer technique, and the application of nano-filled coating increases the longevity of the conventional approximal ART restorations.

Micro-mechanical bond strength tests for the assessment of the adhesion of GIC to dentine.

BACKGROUND: The aim of this study is to critically evaluate the bond strength (BS) of Glass-Ionomer Cements (GIC) to dentine with microtensile (µTBS) and microshear (µSBS) BS tests by assessing their rankings and failure patterns. METHODS: Samples were made on flat dentine surfaces and submitted to µTBS and µSBS. The materials used were: high viscosity GIC (Ketac™ Molar Aplicap-KM), resin-modified GIC (Fuji II-FII), nano-filled resin-modified GIC (Ketac™ N100-N100) and an etch-and-rinse adhesive system with a composite resin (Adper™ Single Bond 2 and Z100™-Z100). All tests were performed with a Universal Testing Machine (24 h water storage, crosshead speed of 1 mm/min). Debonded surfaces were examined with a stereomicroscope (×40) to identify the failure mode. The data was analyzed with two-way ANOVA (p < 0.05) and LSD test. RESULTS: Means were statistically different regarding the tests and materials, indicating that values for BS obtained for each material depend on the test performed. Failure analysis revealed that failures produced by µTBS were mainly cohesive for KM and FII. µSBS failures were mainly adhesive or mixed for all materials. For the µTBS, the rank was Z100 > FII > KM = N100, whereas for the µSBS it was Z100 = FII = KM > N100. CONCLUSION: It may be concluded that distinct micro-mechanical tests present different failure patterns and rankings depending on the material to be considered.

Two-year survival rates of proximal atraumatic restorative treatment restorations in relation to glass ionomer cements and Postrestoration meals consumed.

PURPOSE: The purpose of this study was to investigate the influence of 3 glass ionomer cement (GIC) brands and the postrestoration meal consumed on the survival rate of proximal atraumatic restorative treatment (ART) restorations. METHODS: A total of 804 proximal restorations were placed in primary molars by trained operators and assistants using 3 GIC brands. The materials' mixing/placement times, the room temperature and the postrestoration meal consumed by the subjects were documented. The restorations were evaluated soon after placement and after 2 years by trained and calibrated evaluators. RESULTS: After 2 years, approximately 31% of the restorations had survived. There were no statistically significant differences in the survival rate of the restorations in relation to the GIC brands. The postrestoration meal consumed, which was of "hard consistency," was associated with significantly lower survival rate of the restorations. CONCLUSIONS: The survival rate of the proximal restorations was not significantly affected by the glass ionomer cement brands used, but was significantly influenced by the consistency of the next meal consumed by each child.

Shear bond strengths of three glass ionomer cements to enamel and dentine.

OBJECTIVES: The shear bond strength of three glass ionomer cements (GIC) to enamel and dentine was evaluated. STUDY DESIGN: Sound permanent human molars (n=12) were grinded perpendicular to their axial axes, exposing smooth, flat enamel and dentine surfaces. The teeth were embedded in resin and conditioned with polyacrylic acid (25%; 10s). Twenty four specimens of each GIC: Fuji IX (FJ-GC), Ketac Molar Easymix (KM-3M ESPE) and Maxxion (MX-FGM) were prepared according to the Atraumatic Restorative Treatment (ART) (12 enamel and 12 dentine), in a bonding area of 4.91 mm² and immersed in water (37°C, 24h). The shear bond strength was tested in a universal testing machine. Non-parametric statistical tests (Friedman and post-hoc Wilcoxon Signed Ranks) were carried out (p=0.05). RESULTS: The mean (±sd) of shear bond strength (MPa), on enamel and dentine, were: KM (6.4±1.4 and 7.6±1.5), FJ (5.9±1.5 and 6.0±1.9) and MX (4.2±1.5 and 4.9±1.5), respectively. There was a statistically significant difference between the GICs in both groups: enamel (p=0.004) and dentine (p=0.002). The lowest shear bond value for enamel was with MX and the highest for dentine was KM (p<0.05). CONCLUSION: It is concluded that KM has the best adhesion to both enamel and dentine, followed by FJ and MX.

Two years survival rate of Class II ART restorations in primary molars using two ways to avoid saliva contamination.

AIM: To compare the survival rates of Class II Atraumatic Restorative Treatment (ART) restorations placed in primary molars using cotton rolls or rubber dam as isolation methods. METHODS: A total of 232 children, 6-7 years old, both genders, were selected having one primary molar with proximal dentine lesion. The children were randomly assigned into two groups: control group with Class II ART restoration made using cotton rolls and experimental group using rubber dam. The restorations were evaluated by eight calibrated evaluators (Kappa > 0.8) after 6, 12, 18 and 24 months. RESULTS: A total of 48 (20.7%) children were considered dropout, after 24 months. The cumulative survival rate after 6, 12, 18 and 24 months was 61.4%, 39.0%, 29.1% and 18.0%, respectively for the control group, and 64.1%, 55.1%, 40.1% and 32.1%, respectively for the rubber dam group. The log rank test for censored data showed no statistical significant difference between the groups (P = 0.07). The univariate Cox Regression showed no statistical significant difference after adjusting for independent variables (P > 0.05). CONCLUSION: Both groups had similar survival rates, and after 2 years, the use of rubber dam does not increase the success of Class II ART restorations significantly.

Influence of the cavity-size on the survival rate of proximal ART restorations in primary molars.

AIM: To evaluate the influence of the size of proximal cavities on the survival rate of the atraumatic restorative treatment (ART) restorations. DESIGN: A total of 804 children, aged 6-8 years, from a low socio-economic community, with an ART restorable proximal carious lesion in their primary molars, participated. Over a 3-week period, three 'experienced' and four 'inexperienced' operators randomly paired with four 'experienced' and four 'inexperienced' assistants, made the restorations at site using hand instruments. They randomly used Fuji IX, Ketac Molar Easymix and Ketac Molar Aplicap glass ionomer cements to restore the cavities, under randomly selected rubber dam and cotton roll isolation methods. The fillings were independently evaluated by nine trained and calibrated evaluators. RESULTS: After 1 year, the survival rate of the fillings evaluated in the study was 44.8%. Irrespective of the other factors involved, restorations with the highest survival rate were of size between 2 and 3 mm (mesio-distal, bucco-lingual, and depth) or volumes 10.0-19.9 mm(3) (Chi-square, P = 0.002, KM mean survival of 345 days). CONCLUSIONS: While the survival rates for class II ART restorations were still low, the choice of medium-sized proximal cavities gave better survival rates for this technique.

Survival Rate of Atraumatic Restorative Treatment (ART) Restorations Using a Glass Ionomer Bilayer Technique with a Nanofilled Coating: A Bi-center Randomized Clinical Trial.

PURPOSE: The high-viscosity consistency of glass ionomer cement (GIC) contributes to its inappropriate adaptation, while the material's premature exposure to humidity decreases its mechanical properties. This study's purposes were to: (1) investigate approximal atraumatic restorative treatment (ART) restorations' survival in primary molars using two different insertion techniques and two surface protection materials; and (2) compare the results of cities where treatments were performed. METHODS: A total of 389 six- to seven-year-olds were selected from two cities in Brazil and randomly assigned into four groups: (1) ART restorations plus petroleum jelly (PJ); (2) bilayer-ART restorations plus PJ; (3) ART restorations plus nanofilled coating for GIC (NC); (4) bilayer-ART restorations plus NC. Restorations were evaluated after one, six, 12, 18, and 24 months. Kaplan-Meier survival analysis, log-rank test, and Cox regression analysis were performed. RESULTS: Restorations' cumulative survival was 46.4 percent. There was a higher survival of bilayer-ART restorations (P=0.03). No difference was observed between surface protection materials (P=0.57). Restorations made in Barueri were almost 2.5-fold more likely to survive than those from Recife (P<0.001). CONCLUSIONS: The bilayer technique improves approximal ART restorations' survival in primary molars. The nanofilled coating does not influence restorations' survival rate, and the city where treatments were performed influences restoration survival.

Early Childhood Caries (ECC): an infectious transmissible oral disease.

Dental caries in babies and toddlers is called Early Childhood Caries (ECC). It is an infectious and transmissible die-to-bacterial disease. Detailed knowledge regarding the acquisition and transmission of infectious agents facilitates a more comprehensive approach toward prevention. Mutans streptococci are important organisms in the initiation and progression of dental caries. Recent evidence demonstrates that these bacteria are found in the mouths of pre-dentate infants and are acquired via vertical and/or horizontal transmission from human reservoirs. This information should facilitate the focusing of clinical interventions that prevent or delay infant infection, thereby reducing the prevalence of dental caries (ECC) in babies and toddlers.