Survival rate of approximal-ART restorations using a two-layer technique for glass ionomer insertion.

OBJECTIVE: Good survival rates (SR) have been reported for occlusal-atraumatic restorative treatment (ART) restorations but not for approximal-ART restorations. The high-viscosity consistency of the glass ionomer cement (GIC) may lead to its incorrect adaptation into the cavity and thus to failure of the restoration. Because the use of a flowable GIC layer seemed to improve its adaptation in approximal restorations in vitro, we evaluated whether the use of an intermediate flowable GIC layer would improve the SR of approximal-ART restorations. METHODS: A total of 208 children (6-7 years old) with at least one occluso-proximal carious lesion in a primary molar were selected and randomly allocated to two groups: G1, conventional technique, one-layer GIC (powder/liquid ratio 1:1); and G2, two-layer technique, consisting of a first layer of GIC with a flowable consistency (powder/liquid ratio 1:2) and a second layer of a regular consistency. Restorations were made by final-year students and evaluated after 1, 6, 12 and 18 months. Restoration survival was evaluated using Kaplan-Meier survival and logrank test. Poisson regression analyses (α = 5) were used to verify the influence of factors such as insertion technique, restoration surface and operators. RESULTS: The overall SR of the restorations after 18 months was 68 %. There was no difference in SR between the techniques, neither did the other factors influence the SR. CONCLUSIONS: Over 18 months, the use of an intermediate flowable GIC layer in approximal-ART restorations does not improve the restoration survival. CLINICAL RELEVANCE: This study suggests that the two-layer technique is not the answer for increasing approximal-ART restoration longevity.

The effect of GIC-brand on the survival rate of proximal-ART restorations.

BACKGROUND: Laboratory studies show diverse behaviour of different brands of glass-ionomer cements (GIC). AIM: This study investigated the clinical performance [survival rate (SR)] of three GIC brands applied to proximal atraumatic restorative treatment (ART) restorations. Additionally, the SR of the tooth was evaluated. DESIGN: Proximal cavities of 262 primary molars were restored. The patients had been randomly allocated to two operators and three GIC brands: Fuji IX, Hi-Dense, and Maxxion R. Restorations were evaluated after 1, 6, 12, 18, 24, 30, and 36 months. Failed restorations were, if possible, repaired or replaced. Linear regression analyses were used to evaluate the effect of GIC brand, operator, and surface of restoration. Kaplan-Meier survival analysis and log-rank test were performed for both restoration survival and tooth survival (α = 5%). RESULTS: After 3 years, 82.4% of the restorations were evaluated. The SR of the restorations was 24.4%, and there was no difference among GIC brands (log-rank test, P = 0.6). In the first 18 months, a significant operator effect and significantly higher failures in distal surfaces were found. The SR of the tooth was 81.7%. CONCLUSIONS: The SR of proximal ART restorations was relatively low when compared with the SR of the tooth. There are no differences in the performance among the GIC brands used in the study.

A preliminary clinical trial using flowable glass-ionomer cement as a liner in proximal-ART restorations: the operator effect.

OBJECTIVES: This in vivo study was carried out to assess the influence of the operator experience on the survival rate of proximal-ART restorations using a two-layer technique to insert the glass-ionomer cement (GIC). STUDY DESIGN: Forty five proximal cavities in primary molars were restored in a school setting according to the ART technique. The cavities were restored by two operators with Ketac Molar Easymix, and received a flowable layer of GIC prior to a second GIC layer with a regular consistency. The operators had different clinical experiences with ART (no experience or two years of experience), but both completed a one-week training to perform the restorations and the GIC mixing in this study. RESULTS: After a 12-month follow-up, 74% of the restorations survived; the main reason for failure was bulk fracture or total loss of the restoration.There was no operator influence (long-rank test p=0.2) CONCLUSION: The results encourage future well designed controlled clinical trials using the two-layer technique for insertion of GIC in proximal-ART restorations, after training the operators.

Flowable glass ionomer cement as a liner: improving marginal adaptation of atraumatic restorative treatment restorations.

PURPOSE: The present study aims to evaluate the in vitro microleakage of two layers GIC proximal restorations in primary molars. METHODS: Forty primary molars received proximal cavity preparations and were randomly divided in two groups. G1 was restored with a regular powder/liquid ratio GIC. G2 firstly received a flowable layer of GIC and secondly a regular GIC layer. After 24h water storage (37 degrees C), the teeth were made impermeable with the exception of the restoration area and 1 mm of their surrounding, immersed in 0.5% methylene blue solution (4h), rinsed and sectioned mesio-distally. One side was polished and analyzed under light microscope. Replicates from the other side were observed under SEM. Microleakage evaluation was carried out by 3 evaluators. RESULTS: The data analysis (Mann-Whitney) showed a significant (P<0.01) better result for G2. Regarding the SEM evaluation, irregularities were observed in the G1 at the tooth/GIC interface. For G2, it was not possible to observe any displacement of the GIC in relation to the tooth structure, which confirmed better adaptation as seen in the microleakage test. CONCLUSION: the insertion of a flowable GIC layer in proximal cavities before the insertion of a regular GIC layer improves the material adaptation to the tooth.