The effect of triangular cross-section neck design on crestal bone stability in the anterior mandible: A randomized, controlled, split-mouth clinical trial.

Objectives: This randomized controlled trial aimed to compare crestal bone loss (CBL) and buccal bone thickness (BBT) around triangular cross-section neck (TN) to round neck (RN) implants retaining mandibular overdentures one year after loading, using cone beam computed tomography (CBCT).

Material And Methods: Twenty edentulous patients receiving 40 implants with similar diameters were randomly assigned to the RN and TN groups. Clinical buccal bone thickness (CBBT) around the implants was measured with a caliper at baseline. A resonance frequency analyzer was used to measure the implant stability quotient (ISQ) at the baseline and two months after insertion. Pocket probing depths (PPD), plaque index (PI), and gingival index (GI) were also recorded at postoperative months 2, 6, and 12. CBCT was used to evaluate proximal CBL and BBT at three levels (0, -2, and -4 mm) one year after loading.

Results: No implant loss was observed during the follow-up period. No significant differences in CBBT, ISQ values, and scores for PPD, PI, and GI between the two groups were observed at any time (p > .05). BBT was also comparable one year after loading (p > .05). The mean ± SD proximal CBL one year after loading was 0.58 ± 0.36 mm for TN and 0.91 ± 0.59 mm for RN (p < .01).

Conclusions: This study found better crestal bone preservation in the implants with the novel neck design than conventional neck design in the anterior mandible after a follow-up of one year. However, it may not be clinically noticeable.