All ETDs from UAB

Advisory Committee Chair

Ramzi Abou-Arraj

Advisory Committee Members

Nicolaas Geurs

Amjed Javed

Nathaniel Lawson

Perng-Ru Liu

Document Type

Thesis

Date of Award

2021

Degree Name by School

Master of Science in Dentistry (MScD) School of Dentistry

Abstract

Implantoplasty is defined as the mechanical removal of the implant threads and the macroscopically rough implant surface. Clinical outcomes such as probing depth and bleed-ing on probing measurements were shown to improve significantly after implantoplasty and peri-implant bone stability was achieved in the majority of the cases.This in-vitro study aims to investigate the effects of implantoplasty on the implant’s maximum compressing force and the type of failure that occurred on different implant sys-tems with different sizes, materials, collar designs and prosthetic connections. A total of 132 screw-shaped titanium implants from different manufacturers (Bi-oHorizons, Zimmer Biomet, and Nobel Biocare) and different diameters ranging from nar-row (3.4mm and 3.5mm) to regular (3.7mm, 3.8mm and 4.3mm) to wide (4.6mm and 4.7mm) were included. Ten test implants were subjected to implantoplasty while 10 im-plants served as control in each diameter group. The duration of implantoplasty, the mean amount of implantoplasty at the collar zone and the thread zone, the minimum and maxi-mum amount of implantoplasty at the thread zone, and the maximum compression force prior to implant failure and the failure type were recorded. Means and standard deviations were calculated for all continuous outcomes and failure types were summarized as frequen-cy and proportion for each group. Comparison of group means has been carried out using the t-test (2 groups) or the ANOVA test followed by the Tukey’s HSD post hoc test (more than 2 groups) while the Fisher’s exact test was used for the group comparison of the dis-tribution of failure types. More time was required to achieve a smooth surface with increasing implant diame-ters (308.9s, 367.6s and 375.5s for narrow, regular and wide respectively (P = 0.0002)). Less grinding was achieved at the level of the implants’ collar (mean reduction ranged from 0.055 to 0.109mm) compared to the implant body (mean maximum reduction at thread ranged from 0.344 to 0.466mm). Less implantoplasty in the thread zone was performed at narrower diameter implants (0.152, 0.188 and 0.216mm of reduction for narrow, regular and wide implants respectively (P < 0.0001)). A reduction of the maximum compression force of implants from 0.80% to 50% occurred after implantoplasty with values ranging from 709.4 to 1587.7N for control implants and 416.9 to 1474.1N for test implants (P = 0.0372, 0.0015 and 0.5170 for narrow, regular and wide implants respectively). All control and 50% of test narrow implants fractured at the implant body level while 50% test im-plants fractured at the collar. Control regular diameter implants had only one fracture of the collar while 66.7% had a collar deformation whereas 51.9% of test implants experienced a collar fracture and 7.4% a body fracture. No fractures of wide diameter implants were reg-istered and only platform deformations and fracture of abutment screws happened in similar proportions in control and test implants. In conclusion, implantoplasty negatively affected the mechanical strength of narrow and regular diameter (≤4.3mm) implants with insignificant changes to wide implants (≥4.6mm). Alternate treatments should be considered for peri-implantitis with narrow im-plants due to the increased fracture risk.

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