Influence Of Injection Technique And Material On Composite Veneer Precision

This study aimed to compare the precision of composite veneer fabrication using digital software on frontal teeth using two injection techniques and two flowable composites by comparing printed wax-up and veneer models. Based on an initial intraoral scan of the maxilla, 40 identical resin models were fabricated using a 3D printer. A digital wax-up of the maxillary incisors was designed in CAD software and printed. Transparent silicone keys of vinyl polysiloxane were made on the wax-up model. Two materials were used: a universal flowable composite (UF) and a high-viscosity flowable composite (HF). Each material was injected in two different points: through the incisal edge (I) and through the vestibular surface (V). Composite veneers were scanned with a laboratory scanner and compared to the wax-up model. Discrepancies were measured at four points: the gingival third, middle third, incisal third, and incisal edge. Statistical analysis was performed using the Kruskal-Wallis test (p<0.05). The greatest deviations were at the incisal edge in incisal injection and in the gingival third in vestibular injection. The smallest deviations varied across groups. A statistically significant difference was observed among techniques and materials. Both techniques and both materials influence restoration quality. Discrepancies suggest an influence of vinyl polysiloxane properties on precision.