J Periodontal Implant Sci.  2022 Oct;52(5):422-434. 10.5051/jpis.2106420321.

The healing pattern of a 4 mm proximal infrabony defect was not significantly different from a 2 mm defect adjacent to dental implant in a canine mandible

• Anv MK
• Kim HJ
• Choi JU
• Kim KH
• Lee YM
• Rhyu IC
• Seol YJ

• KMID: 2557588
• DOI: http://doi.org/10.5051/jpis.2106420321

Abstract

Purpose
The purpose of this study was to evaluate and compare the healing patterns of 2-mm and 4-mm proximal infrabony defects adjacent to dental implants in canine mandibles.
Methods
Four male beagles were used. Two groups were created: a 2-mm group (n=4) and a 4-mm group (n=4) depending on the horizontal dimension of proximal infrabony defects adjacent to implants. Bone healing patterns between the 2 groups were evaluated and compared at 8 and 16 weeks using radiographic, histological, histomorphometric, and fluorescent labelling analyses.
Results
According to microcomputed tomography, the median bone volume fraction, bone mineral density, and the percentage of radiographic distance from the defect bottom to the most coronal bone-to-implant contact (radio-mcBIC) were 32.9%, 0.6 g/cm ³ , and 73.7% (8 weeks) and 45.7%, 0.7 g/cm ³ , and 76.0% (16 weeks) in the 2-mm group and 57.7%, 0.8 g/ cm ³, and 75.7% (8 weeks) and 50.9%, 0.8 g/cm ³ , and 74.7% (16 weeks) in the 4-mm group, respectively. According to histomorphometry, the median bone area fraction, mcBIC and the percentage of BIC amounted to 36.7%, 3.4 mm, and 58.4% (8 weeks) and 49.2%, 3.4 mm, and 70.2% (16 weeks) in the 2-mm group and 50.0%, 3.0 mm, and 64.8% (8 weeks) and 55.7%, 3.0 mm, and 69.6% (16 weeks) in the 4-mm group, respectively. No statistically significant differences were found between the groups for any variables (P>0.05).
Conclusions
The proximal defects that measured 2 mm and 4 mm showed similar healing patterns at 8 and 16 weeks, and the top of bone formation in the defects was substantially limited to a maximum of 1.6 mm below the implant shoulder in both groups.

Keyword

Animal experimentation; Bone regeneration; Dental implants; Osseointegration; X-ray microtomography