Marginal microleakage of glass ionomer cement with two different cavity conditioners on primary anterior teeth – An in vitro study

Background and Objective: Glass ionomer cements (GICs) are the most commonly used restorative material in pediatric dentistry. They have numerous advantages; however, they show some marginal microleakage at the restoration–tooth interface. Various conditioning agents have been tested for alteration or dissolution of smear layer which has been attributed to the occurrence of microleakage; however, very limited studies have been done using primary teeth. Aims: To evaluate and compare the effect of 10% polyacrylic acid and 17% EDTA on marginal microleakage of high-viscosity GIC. Settings and Design: Experimental, in vitro study. Methodology: Class V cavities of standardized dimensions were prepared on 60 primary anterior teeth and were randomly divided into three groups. Except Group I, the cavities of Groups II and III were conditioned with 10% polyacrylic acid and 17% EDTA, respectively. All the 60 teeth were then restored with high-viscosity GIC. The samples were thermocycled and immersed in methylene blue solution for 24 h. The teeth were removed from the stain, rinsed, and sectioned buccolingually and were observed under stereomicroscope at 30× to score the marginal microleakage. Statistical Analysis Used: Kruskal–Wallis test followed by Mann–Whitney post hoc analysis were used to compare the mean marginal leakage scores between the three study groups. Results: Statistical significance difference was found between all the three groups (P < 0.05). The mean marginal microleakage score was maximum for Group I (control group; 3.00), whereas it was the least for Group II (1.30) where 10% polyacrylic was used for conditioning the cavity surface. Conclusion: Among the study groups, none of them was completely devoid of microleakage in all its samples. 10% polyacrylic acid emerged as a better conditioning agent when compared with 17% EDTA in altering or removing the smear layer thereby resulting in better adhesion.

Influence of dental exposure to oral environment on smear layer removal and collagen exhibition after using different conditioning agents

Although in vitro studies have shown encouraging results for root surface conditioning with demineralizing agents, in vivo studies have failed to show its benefits in periodontal healing. This can be attributed to several factors, among which, the hypermineralization of dental surface. Therefore, this in vitro study compared, using scanning electron microscopy (SEM), the effect of root surface conditioning with different conditioners (1% and 25% citric acid, 24% EDTA and 50 mg/mL tetracycline hydrochloride) in impacted teeth and in teeth that had their roots exposed to the oral environment. One trained examiner assessed the SEM micrographs using a root surface modification index. There was a tendency of more root surface modification in the group of impacted teeth, suggesting that the degree of root mineralization influences its chemical demineralization.

Apesar de estudos in vitro terem demonstrado resultados favoráveis ao condicionamento da superfície radicular com agentes desmineralizantes, estudos in vivo não mostraram seus benefícios na cicatrização periodontal. Isto pode ser atribuído a vários fatores, entre os quais, a hipermineralização da superfície dental. Portanto, este estudo in vitro comparou, usando microscopia eletrônica de varredura, o efeito do condicionamento da superfície radicular com diferentes condicionadores (1% e 25% de ácido cítrico, EDTA 24% e 50 mg/mL de cloridrato de tetraciclina) em dentes impactados e dentes que tinham suas raízes expostas ao meio bucal. Um examinador treinado avaliou as microscopias eletrônicas de varredura utilizando um índice de modificação da superfície radicular. Houve uma tendência de maior modificação da superfície radicular no grupo de dentes impactados, sugerindo que o grau de mineralização da raiz influencia a sua desmineralização química.