To evaluate the effect of a novel restorative approach using dimethyl sulfoxide (DMSO) as a cavity pretreatment on the material fracture and retention (primary outcome) of direct composite fillings placed on cervical carious lesions (CCLs). 45 patients presenting CCLs were screened and randomized into two groups containing 37 caries lesions/group: an untreated control (20 patients) and a DMSO-treated (25 patients) group. Following a parallel-study design, two calibrated operators placed 74 (n=37) composite fillings (Filtek Z350XT, 3M ESPE) using a 2-step etch-and-rinse adhesive (Single Bond 2, 3M ESPE). After baseline assessments (7 days), fillings were evaluated at 12-, 24- and 36-month follow-ups according to the FDI criteria (fracture/retention, marginal staining, marginal adaptation, postoperative sensitivity and caries recurrence). For statistical analysis, Chi-Square and Cochran's Q tests were used (α=0.05) following the Bonferroni correction. DMSO had significant effects on the clinical performance of composite fillings placed on CCLs according to the FDI criteria ( p <0.05). Success rates after 36 months of untreated and DMSO-treated cavities were 65% and 89%, respectively, with a 70% lower risk of failure when using DMSO. DMSO significantly reduced post-operative sensitivity and marginal staining and improved retention rates after 36 months ( p <0.05). Long-term clinical performance of composite fillings using simplified etch-and-rinse adhesives can be optimized by employing DMSO as a cavity pretreatment. The use of DMSO can be a simple clinical approach to improve post-operative sensitivity of composite fillings, reduce risk of failures and extend service life by producing more stable composite-tooth interfaces.
Ismail et al. (Sun,) studied this question.