Comparative evaluation of crestal bone loss and implant stability during initial healing period between two implant designs: A split-mouth study.

Background: Crestal bone loss common with different implant neck designs has been studied only after a healing period of three months. This study compares the difference in crestal bone loss and implant stability between smooth and microthreaded neck designs during the initial healing period.

Subjects and methods: This experimental split-mouth study was done at the Department of Prosthodontics. The study enrolled 20 participants with missing mandibular posterior teeth on both sides of the arch, fulfilling inclusion and exclusion criteria. Each subject received smooth-collared (Group SC) and microthread collared (Group MT) implant neck designs on either side for the replacement of mandibular posterior teeth. Alveolar marginal bone loss assessment at the time of implant placement and after three months was done with an intraoral periapical radiograph. Implant stability (ISQ) values were measured by magnetic technology resonance frequency analyzer (RFA) at the above two timelines.

Statistical analysis used: t-test.

Results: Significantly less crestal bone loss (P ≤ 0.05) was observed in Group SC as compared to Group MT at the end of three months. ISQ comparison at baseline and three months between Groups SC and MT showed significantly greater mean value for microthreaded implants at baseline but no significant difference at the end of three months.

Conclusions: Smooth-collared implant design showed significantly less crestal bone loss in comparison with microthreaded implant design, probably due to lesser microbial colonization and stress development at the time of placement. As microthreaded collar design had significantly higher implant stability at baseline, such implants may be more favorable for immediate loading protocol.