Design of customized soft tissue substitutes for anterior single-tooth and posterior double-tooth defects: An in vitro study.

ABSTRACT

OBJECTIVE: This study aims to validate the standardized procedure for designing soft tissue substitutes (STS) adapted to optimally fit single-tooth defects in the anterior jaws and double-tooth defects in the posterior jaw and to compare mathematically modeled average shapes. MATERIALS AND METHODS: Casts from 35 patients with 17 single-tooth defects in anterior region and 21 double-tooth defects in posterior region were scanned. STS were designed and sectioned in 3D slices meshes. Thickness values were documented respecting mesial-distal and buccal-lingual orientations. Graphs were embedded into images, and hierarchical clustering was applied to group STS according to shape and thickness. RESULTS: STS clustered into two groups per defect type. For anterior single defects, STS (n = 4) were either a small and thin oval 7 mm buccal-lingual, 4-5 mm mesial-distal direction and 1.1-1.5 mm thick or a larger oval (n = 13) 9 mm buccal-lingual, 5-7 mm mesial-distal and 1.6 m thick. For posterior double tooth defects, STS (n = 10) were either narrow, long and thick 6-7 mm buccal-lingual, 16-20 mm mesial-distal and 2.2 thick or a wide, thinner rectangle (n = 11) 9-11 mm buccal-lingual, 12-14 mm mesial-distal and 1.1-1.5 mm thick. CONCLUSIONS: The study validated the standardized digital method to design grafts for soft tissue volume augmentation and identified four average shapes for anterior single-tooth and posterior double-tooth soft tissue defects. CLINICAL SIGNIFICANCE: We developed and validated a standardized digital method to design an optimal geometrical shape of a soft tissue substitute for oral volume augmentation and combined it with mathematical modeling to identify average shapes for single-interior, and double-posterior tooth defects. The identified average shapes offer the possibility to produce better-fitted xenografts or synthetic STS blocks requiring minimal chair-side adaptation leading to reduced clinical time and patient discomfort and potentially improving soft tissue volume augmentation outcomes.