The aim of this study was to evaluate the effects of deproteinization and two different cavity designs on the performance of resin restorations placed in the cavities of MIH-affected molars.
Method:
95 MIH-affected PFMs and 31healthy PFMs (126 teeth in total) were included in this study. The MIH-affected molars were divided into three groups. In Group I, all hypomineralized tissue was removed until the cavity margins ended in healthy enamel. In Group II, carious and cheesy hypomineralized tissue with carious tissue was removed until a reasonable resistance was sensed in the hypomineralized tissue. In Group III, deproteinization of the hypomineralized tissue was performed prior to the placement of CRRs. Group IV served as a control consisting of healthy molars. Restorations were evaluated according to modified USPHS criteria.
Result:
The recall rate of patients was 100%. The retention rates were 93.7% for Group I, 80.7% for Group II, 93.5% for Group III and 100% for Group IV. The success rate for the restorations in Group II proved significantly lower (p<0.05) than that of the other three groups. No significant differences in success rates were observed between Group I, Group II and Group IV (p>0.05) at the end of 24 months. Anatomic form, marginal adaptation and marginal discoloration scores were found to be lower in Group II, which negatively impacted the success of the restorations beyond the twelve-month recall. The surface roughness of all restorations was acceptable in each group throughout the study. No significant differences were observed in secondary caries or surface roughness between any of the groups in the study (p>0.05).
Conclusion:
Restoration failure was found to be significantly higher (p<0.05) in Group II, in which hypomineralized tissue remained around the cavity margins. Deproteinization of hypomineralized enamel was found to enhance the retention rates of restorations.