BackgroundOpen gingival embrasures form complex aesthetic and functional problems. This clinical trial assessed the bioclear matrix using injection molding technique against conventional celluloid matrix technique in management of black triangle.MethodsA total of 26 participants were randomly divided into two groups (13 participants each) according to the technique used. In group (A) celluloid conventional matrix method was used, while in group (B) bioclear matrix with injection molding technique was used. The different outcomes (Esthetic evaluation, marginal integrity and patient satisfaction) were evaluated following the FDI criteria by two blinded examiners. The evaluation was done at (T0) (immediate after restoration); (T6) after 6 months; and (T12) after 12 months. Statistical analysis was done as categorical and ordinal data were presented as frequency and percentage values. Categorical data were compared using fisher’s exact test. Intergroup comparisons for ordinal data were analyzed utilizing the Mann–Whitney U test, while intragroup comparisons were analyzed using Friedman’s test followed by the Nemenyi post hoc test. The significance level was set atp≤ 0.05 within all tests.ResultsRegarding radiographic marginal integrity and marginal adaptation, the bioclear matrix group revealed superior results when compared to celluloid matrix group with a significant difference between both groups at all intervals (p< 0.05); however no significant difference was detected at different intervals. While for proximal anatomical form and esthetic anatomical form, as well as phonetics and food impaction, all cases in both groups were successful with no statistical significant difference between groups. For the periodontal response, there was no significant difference between groups. However, there was a significant difference between scores measured at different intervals, with T0 being significantly different from other intervals (p< 0.001). Marginal staining revealed that there was no significant difference between groups. While, a significant difference between scores measured at different intervals.ConclusionsThe restorative management of the black triangle with both protocols was able to deliver superior aesthetic and good marginal adaptation; suitable biological properties; with adequate survival time. Both techniques were almost equally successful, however they are depending on the operator skills.Trial registrationThe clinical trial was registered in the (www.clinicaltrials.gov/) database in 23/07/2020; with the unique identification number NCT04482790.