Comparative evaluation of aesthetic outcome of direct polychromatic composite layering and the "index cut-back technique" for restoring class IV defects using a newly patented simulated 3D printed mould: An in vitro study

Aim: The Purpose of This In-Vitro Study Was to Comparatively Evaluate the Aesthetic Outcome Of Direct Polychromatic Layering Of Anterior Composites Restoration With The "Index Cut-Back" Technique While Restoring Class IV Defects of Teeth.

Methodology: An extracted tooth specimen of maxillary central incisor crown was 3-D scanned for obtaining its dimensions, these dimensions were transferred to AUTOCAD™ software and a customised 3-D Printed mould was fabricated (Temporary Patent no. 336763-001 ). 50 specimens of Maxillary Central Incisor Crowns were then constructed with the help of Composite restorative material (Palfique Estelite LX5, Tokuyama Dental Corporation, Japan) in this mould. Afterwards with the help of a Straight fissure diamond bur a standardized size (4 cm length x 4 cm width) class IV defect was created on all 50 specimens and then they were allocated to 2 groups, Group A & B. 25 specimens for each Group (N = 25). Group A was restored using conventional Direct Polychromatic Layering technique and Group B was restored using the "Index cut-back" Technique. Shade Outcome and Translucency were evaluated using Spectrophotometer and Time taken was evaluated using a stop-watch chair side.

Results: There was a significant difference in the values (P < .05) between Group A (Polychromatic) & Group B (Index cut-back) in terms of both Shade Outcome & Translucency; Group B showed better aesthetic values (closer to baseline) than Group A. In contrast, Time required for restoring the Class IV defects was significantly lower in Group A compared to Group B (P < .05).

Conclusion: The Index Cut-Back Technique showed superior aesthetic outcome restoring Class IV defects, however it requires a planned pre-operative course of action before executing the clinical procedure.