Observation of Changes in Alveolar Bone Healing during the Course of Healing after Guided Bone Regeneration.
Abstract: (Part I) Postoperative Complications Following Guided Bone Regeneration: The use of Double-flap technique Conventional periosteal fenestration technique is the most commonly used technique for flap advancement in GBR (guided bone regeneration) procedures to achieve tension-free primary closure. However, its limitations include efficacy and morbidity. To overcome such drawbacks of the con... read moreventional technique, recently, the double flap-incision technique was reported and is now widely used by the investigators. The objective of the study is to compare the pain/discomfort level and the frequency of postoperative complications including membrane exposure rate (morbidity) as well as the amount of flap advancement (efficacy) between two different techniques. Patients who needed vertical /horizontal ridge augmentation of partially edentulous upper and lower jaws were included in the study. Periosteal fenestration technique (PFT) was performed in 18 sites and double-flap technique (DFT) was performed in 11 sites by a single operator. The questionnaire regarded postoperative pain, swelling and bleeding one week after GBR procedures using a VAS scale from one to ten scores. Any other complications including membrane exposure, infection and paresthesia were recorded at follow-up visits up to 24 weeks after GBR. A total of 23 patients with 29 surgical sites were enrolled for the study. The healing during six months period was uneventful in 22 surgical sites. Within the limitations of this study, there were no statistically significant differences in the pain/discomfort level for the patient in the following categories: pain (mean score 1.55 vs. 2.89; P=0.15), swelling (mean score 1.91 vs. 2.78; p=0.074), and bleeding (mean score 0.0 vs. 0.72; P=0.245). The frequency of post-operative complications (9.1% vs. 33.3%; P=0.149) such as paresthesia, continuous discomfort (membrane dislocation) and the membrane exposure rate (9.1% vs. 11.1%; p= 0.874) were lower in DFT group and than PFT group. The mean flap advancement (mm) of Double-flap technique was significantly greater than the mean flap advancement of the conventional periosteal fenestration technique (9.64 mm vs. 7.13 mm; P=0.025). Double-flap technique showed comparable clinical performance with conventional periosteal fenestration technique in GBR. Results also indicated that the DFT significantly enhances flap advancement compared to the conventional periosteal fenestration. This new technique can be utilized as an alternative option to the conventional technique. (Part II) Observations in Alveolar Bone Volume Changes during the course of healing after Guided Bone Regeneration Clinical observation demonstrates that the amount of initial bone volume created by guided bone regeneration (GBR) does not equal the amount of bone after healing. A review of literature has revealed a loss of alveolar bone width and height during the healing time. In the past literature, one study quantified the changes following GBR using collagen membrane and demineralized freeze-dried bone allograft (DFDBA) indicating significant non-uniform loss of augmented bone. However, none of the studies discussed the amount of bone changes after GBR using an expanded polytetrafluoroethylene (e-PTFE) membrane and freeze-dried bone allograft (FDBA). The objective of this study is to evaluate the changes of alveolar bone volume during the course of 6 months of healing after GBR using FDBA and an e-PTFE membrane. 18 surgical sites requiring vertical/horizontal ridge augmentation of partially edentulous upper and lower jaws prior to dental implant placement were included in the study. By using an acrylic stent as a reference point, the measurements of bone volume were evaluated three times: Original Bone (OB) just before bone grafting, Post GBR (PB) just after GBR, and Healing Bone (HB) six months after GBR. Vertical measurements were recorded at designated implant locations and horizontal measurements were recorded at 3mm, 5mm, and 7 mm from the bone crest at designated implant locations. The results showed a significant change of alveolar bone volume during the course of 6 months healing following GBR using FDBA and e-PTFE membrane. The mean loss of augmented bone ranged from 4% to 21% during six months healing. There were unpredictable volume changes with vertical dimension and in areas with soft tissue invagination. Vertical augmentation using FDBA and e-PTFE membrane is successful in maintaining the volume. A close adaptation, stabilization and firm fixation of the membrane are desired in the grafted sites with the non-resorbable membranes. Proper surgical planning is indispensable for clinicians who need to consider accurate over-augmention of alveolar bone to achieve a predictable outcome for GBR.
Thesis (M.S.)--Tufts University, 2012.
Submitted to the Dept. of Periodontology.
Advisor: Yong Hur.
Committee: Terrence Griffin, Wai Cheung, and Matthew Finkelman.
Keyword: Dentistry.read less