Inter-implant distance and buccal wall thickness for a novel implant design: a preclinical study

Abstract

Abstract Objectives: This study aimed to assess bone height between adjacent tapered implants of a novel design at different inter-implant distances, and to assess the impact on implant distance from the buccal bone wall. Materials and Methods: Mandibular premolars (P2-P4) and first molar (M1) were extracted from ten minipigs. Fully-tapered implants with threads wider than the implant shoulder diameter were placed after 12 weeks. In the right hemi-mandible, four implants were placed with inter-implant thread distances of 1, 2, or 3 mm, while three implants were placed in the left hemi-mandible with distances from implant threads to outer buccal wall of >1 mm, 0.5 – 1 mm, or <0.5 mm. After 12 weeks, histomorphometrical analysis was performed to evaluate: a) first bone-to-implant contact (fBIC), total BIC, bone area-to-total area (BATA) and coronal bone height between implants (Bi ½ max) for inter-implant distance evaluation, and b) fBIC, BIC and perpendicular crest to implant shoulder (pCIS) for buccal wall evaluation. Results: No significant differences in bone healing were noted for any of the inter-implant distances. Bone healing was significantly compromised when distance from the implant to the outer buccal wall was <0.5 mm. Conclusions: In this experimental model, crestal bone level was maintained between two adjacent implants down to an inter-implant distance of 1 mm. However, minimum buccal wall thickness of 1 mm may be required to avoid bone loss. Clinical relevance: Inter-implant distance and buccal bone thickness are relevant in daily clinical practice and requires additional preclinical research to clarify treatment concepts.