Document Type

Thesis

Date of Degree

Summer 2015

Degree Name

MS (Master of Science)

Degree In

Dental Public Health

First Advisor

Gustavo Avila-Ortiz

Abstract

Objectives:

Tooth extraction initiates a cascade of events that often leads to local anatomic changes in the alveolar ridge. Ridge preservation is a surgical approach aimed at minimizing hard and soft tissue volume loss. There have been contradicting reports on the efficacy of socket grafting for alveolar ridge preservation. Interestingly, there is a paucity of adequately powered randomized controlled clinical trials. The purpose of this study was to assess the effect of the application of a socket grafting technique on alveolar ridge dimensional changes following tooth extraction.

Methods:

Healthy patients requiring the extraction of one single-rooted tooth on either arch, from second premolar to second premolar, excluding mandibular incisors, and who met the eligibility criteria were recruited. Patients were then randomly assigned to either the control group, consisting of tooth extraction alone, or the experimental group, which consisted of extraction and simultaneous ridge preservation using an allograft bone material to fill the socket and a dense polytetrafluoroethylene membrane (dPTFE) to seal it. Cone beam computed tomography (CBCT) was obtained immediately prior to extraction (baseline) and at 14 weeks. Linear measurements with the use of a tooth-supported stent were obtained immediately after extraction (baseline) and at 14 weeks. Linear and volumetric measurements were made using data obtained from the CBCTs. Masked, calibrated examiners performed all radiographic measurements. Measurements obtained included buccal keratinized tissue width, buccal and lingual plate height and width, alveolar ridge horizontal width (CBCT); and alveolar ridge volume changes. Digital planning of dental implants was performed in the ideal restorative location and need for additional grafting was virtually determined. The primary outcome of interest was volumetric reduction of the alveolar ridge at 14 weeks. Linear mixed model statistical analyses were used to compare the mean change in the measurements between the grafted and control groups.

Results:

A total of 59 subjects were recruited, of which 53 patients (27 control and 26 experimental) completed the study. No statistically significant difference was found between the two groups at baseline for any of the parameters analyzed. At the 14 week follow-up appointment there was an average loss in height of the buccal plate of 1.17 mm and 0.61 mm for the control (CG) and experimental (ARP) groups, respectively, showing statistical significance (p=0.012). The lingual plate height was reduced 0.7 mm in CG and 0.47 mm in ARP with no statistical significance (0.075). A linear loss in the buccal-lingual dimension of the alveolar ridge was noted radiographically in both groups, 1.68mm in CG and 1.07mm in ARP, which demonstrated a statistical significant difference between them (p=0.023). Volumetric analysis demonstrated a mean volume loss of 15.83% in the CG showing statistical significance from the 8.36% loss shown in the ARP group. This difference demonstrates a clinical significance when virtual planning of implant placement in the ideal restorative location revealed the need for additional grafting at 13/27 or 48% of CG and 3/26 or 11% of ARP sites. Additionally, a very robust, statistically significant correlation was noted between buccal bone plate width and reduction of alveolar bone volume after 14 weeks of healing (p< 0.0001). A multivariate regression analysis revealed that within the control group a buccal plate <1mm lead to >10% volumetric reduction, while the same reduction in the graft group was only seen when the buccal plate was less that 0.6mm.

Conclusions:

In this study, a novel volumetric analysis of alveolar ridge reduction after tooth extraction was performed, which demonstrated that socket grafting for alveolar ridge preservation does provide a therapeutic benefit. This finding was associated to a decreased probability of requiring additional grafting at the implant site. The thickness of the buccal plate at the time of extraction appears to be a valuable factor to predict the amount of resorption that will take place, meaning that more resorption should be expected, as the buccal plate gets progressively thinner.

Public Abstract

Tooth extraction is a common procedure in dental practices. When a tooth is extracted the alveolar ridge undergoes dimensional changes reducing the tissues at the site where the tooth once existed. These changes can make it difficult for dentists to create esthetically pleasing tooth replacements, and possibly hinder the opportunity to have a dental implant. For this reason a bone graft can be performed into the tooth socket to help maintain the dimensions of the alveolar tissues. This is a technique called socket grafting for alveolar ridge preservation.

The purpose of this study was to assess the effect of the application of socket grafting on alveolar ridge dimensional changes following tooth extraction. A novel volumetric analysis of alveolar ridge reduction after tooth extraction was performed, which demonstrated that socket grafting for alveolar ridge preservation does provide a therapeutic benefit. This finding was associated with a decreased probability of requiring additional bone grafting at the implant site. The thickness of the buccal plate at the time of tooth extraction appears to be a valuable factor to predict the amount of dimensional loss of the alveolar ridge that will take place, meaning that more loss should be expected as the buccal plate gets progressively thinner.

Keywords

publicabstract, Grafting, Preservation, Resorption, Ridge, Socket, Volume

Pages

x, 57 pages

Bibliography

Includes bibliographical references (pages 53-57).

Comments

This thesis has been optimized for improved web viewing. If you require the original version, contact the University Archives at the University of Iowa: http://www.lib.uiowa.edu/sc/contact/.

Copyright

Copyright 2015 Mitchell Miles Gubler

Share

COinS