ABSTRACT
AIM: To compare the 2-year success rates of a Resin Modified Glass Ionomer Cement (RMGIC) with a composite resin in class II primary molar restorations. METHODS: Healthy, cooperative children aged 4-7.5 years with at least one carious primary molar requiring a class II restoration were included in this parallel randomised trial and allocated on a 1:1 basis to composite resin (Z250, 3M ESPE) or RMGIC (Vitremer, 3M ESPE). Restorations were assessed semiannually up to 2 years clinically and radiographically using modified United States Public Health Service criteria, with the primary outcome being all-cause failure. Data were analysed per protocol by binomial linear regression with Relative Risks (RR) and their 95% confidence intervals (CI). RESULTS: 55 patients were randomly allocated to either group and 44 analysed at 2 years; with 49 teeth in the Z250 and 55 teeth in the Vitremer group. The all-cause failure rate for both materials was 3% after 1 year (4 and 2% for Z250 and Vitremer, respectively) and 16% after 2 years (16% for both Z250 and Vitremer). Overall, no difference between materials could be found at 2 years (RR = 1.4; 95% CI 0.8, 2.4; P = 0.30). However, Vitremer was associated with more favourable gingival health compared to composite (RR = 0.2; 95% CI 0.1, 0.9; P = 0.03), but also occlusal wear, which was observed exclusively for Vitremer. CONCLUSION: No significant difference was found in the overall performance of the two materials, making them suitable for class II primary molar restorations, although RMGIC presented more pronounced occlusal wear of limited clinical importance after 2 years.
Subject(s)
Cementation/methods , Composite Resins , Dental Restoration, Permanent , Glass Ionomer Cements , Child , Child, Preschool , Female , Humans , Male , Materials Testing , Resin Cements , Tooth, DeciduousABSTRACT
AIM: This was to examine the occurrence of S. mutans, S. sobrinus and C. albicans in dental plaque and saliva from caries-free and caries-active Greek children. METHODS: Saliva and dental plaque samples from 46 caries-free and 51 caries-active 3-to-13-year-old children were examined using selective media for the three microbes. Identification of isolated mutans streptococci (S. mutans and S. sobrinus) was performed with biochemical test and specific DNA probes. The salivary levels of mutans streptococci were additionally determined by a chair-side test (Dentocult® SM strips). RESULTS: The isolation frequencies of S. mutans, S. sobrinus and C. albicans were 66, 11 and 18 %, respectively. Caries-active children harboured more frequently and at significantly higher numbers the specific microbes than caries-free children. A similar pattern was observed with the Dentocult® SM strip scores. No correlation was found between the presence of these microbes and the age or gender of the children. CONCLUSIONS: Caries experience was statistically significantly related to the presence of all three microbes under study, both in dental plaque and saliva.
Subject(s)
Candida albicans/isolation & purification , Dental Caries/microbiology , Dental Plaque/microbiology , Saliva/microbiology , Streptococcus mutans/isolation & purification , Streptococcus sobrinus/isolation & purification , Adolescent , Age Factors , Bacteriological Techniques/methods , Candida albicans/genetics , Child , Child, Preschool , Colony Count, Microbial , DNA Probes , Female , Humans , Male , Sex Factors , Streptococcus mutans/genetics , Streptococcus sobrinus/geneticsABSTRACT
BACKGROUND: The clinical success of large class II resin-modified glass-ionomer cement/composite resin (RMGIC/CR) 'open-sandwich' restorations in permanent or primary molars may be influenced by certain bonding parameters. AIM: To examine in vitro the effect of placing/curing mode on the RMGIC/CR bond strength. DESIGN: Two restoratives, a CR (Z250), a RMGIC (Vitremer) and a bonding agent (Adper Single Bond 2), all of 3M ESPE, were used for preparing five groups of seven specimen sticks each. The bond between the two restorative materials at the stick centre was created in the three test groups by: (A) 1-step placing RMGIC in contact with CR, then photocuring; (B) 2-step RMGIC placing/curing, then CR placement/curing; (C) 3-step RMGIC placing/curing, bonding agent placing/curing, CR placing/curing. Control groups consisted of sticks made of CR alone (D, positive) and RMGIC alone (E, negative). The specimens were subjected to tensile stress measurements in an Instron dynamometer and examined by scanning electron microscope for type of failure. STATISTICS: Tensile bond strength, tensile strain and elastic modulus differences were examined with one-way ANOVA and Tukey test. RESULTS: Among experimental groups, Group C exhibited significantly higher tensile strength (MPa) means (A = 12.11 ± 4.72, B = 15.69 ± 5.18, C = 19.08 ± 4.05) and significantly higher tensile strain (%) means (A = 0.50 ± 0.11, B = 0.64 ± 0.19, C = 0.98 ± 0.24), compared to Group A, at p = 0.05. Group D had significantly higher tensile strength and strain than all other groups. No statistically significant differences were observed in the elastic modulus. The use of bonding agent (Group C) resulted in absence of adhesive failures as seen by SEM. CONCLUSION: The use of bonding agent improved the CR/RMGIC bond by tensile strength and strain tests.
