Deep Cervical Margin Relocation: A Retrospective Clinical Study

Objectives: The aim of this retrospective clinical study was to evaluate the effectiveness of different composite materials in Deep Cervical Margin Relocation (DMR) in second class cavities. The null hypothesis tested was that there is no difference between flowable and non-flowable materials in DMR nor for the periodontal response (1) nor for the restoration outcome (2).
Methods: Patients who referred to treat at least one deep carious in posterior teeth with the cavity margin below the CEJ were selected. The following periodontal measurements were registered: periodontal probing depth, recession, plaque index, bleeding on probing. After carious tissue excavation, due to the impossibility to isolate the operative field due to soft tissues invasion, the rubber dam was removed and a gengivectomy without osteoplastic was performed. Once checked that the distance between the alveolar crest and the cervical margin was 2mm, suture were positioned and rubber dam was immediately placed. Patients were randomly divided into two groups according to the material employed for the first 1mm thick horizontal layer placed over the cervical margin: a high-viscosity flowable composite (Group 1, Grandioso Heavy-Flow, Voco); a nanofilled composite (Group 2, Grandioso, Voco). At recalls, two independent and blinded calibrated operators performed follow-up examinations, based on periodontal measurements and FDI criteria for restoration outcome evaluation.Data were statistically analyzed with chi-square test and Kaplan-Meyer estimation (p<0.05).
Results: 47 patients were recruited: 26 for Group 1, 21 for Group 2. FDI evaluations criteria showed a statistically significant difference between the two groups at 2-year follow up. According to chi-square test, group 1 showed a better marginal adaptation (p<0.0001) and a worst gingiva health adjacent to the restoration (p<0.0001) then group 2. There are no difference at 24 months in terms of PPD and REC, while BoP was significantly higher when a flowable composite was employed for the deep cervical margin relocation.
Conclusions: Based on the present retrospective study results, the first null hypothesis could be rejected since, after 2-years, flowable composite showed a worst periodontal response than packable composite in DMR.