Clinical, Radiographic, and Histomorphometric Evaluation of a Vertical Ridge Augmentation Procedure Using a Titanium-Reinforced Microporous Expanded Polytetrafluoroethylene Membrane: A Prospective Case Series with 1-Year Follow-Up

Abstract

Vertical ridge augmentation for long-term implant stability is difficult in severely resorbed areas. We examined the clinical, radiological, and histological outcomes of guided-bone regeneration using novel titanium-reinforced microporous expanded polytetrafluoroethylene (MP-ePTFE) membranes. Eighteen patients who underwent implant placement using a staged approach were enrolled (period: 2018–2019). Vertical ridge augmentation was performed in areas with vertical bone defects ≥ 4 mm. Twenty-six implant fixtures were placed in 14 patients. At implant placement six fixtures had relatively low stability. On cone-beam computed tomography, the average vertical changes were 4.2 ± 1.9 (buccal), 5.9 ± 2.7 (central), and 4.4 ± 2.8 mm (lingual) at six months after vertical ridge augmentation. Histomorphometric analyses revealed that the average proportions of new bone, residual bone substitute material, and soft tissue were 34.91 ± 11.61%, 7.16 ± 2.74%, and 57.93 ± 11.09%, respectively. Stable marginal bone levels were observed at 1-year post-loading. The residual bone graft material area was significantly lower in the exposed group (p = 0.003). There was no significant difference in the vertical height change in the buccal side between immediately after the augmentation procedure and the implant placement reentry time (p = 0.371). However, all implants functioned well regardless of the exposure during the observation period. Thus, vertical ridge augmentation around implants using titanium-reinforced MP-ePTFE membranes can be successful.

Techniques on vertical ridge augmentation: Indications and effectiveness

“…In another study by the same research group, expanded polytetrafluoroethylene membranes combined with simultaneous implant placement were able to regenerate 2.94 ± 1.15 mm (89.3 ± 64.2%), 3.27 ± 0.88 mm (130 ± 40.7%), and 3.95 ± 1.79 mm (116 ± 51%) of the defect when they were used without graft, in combination with demineralized freeze‐dried bone allograft, or in combination with autologous graft, respectively 26 . Furthermore, nonresorbable membranes were used in combination with alloplastic materials, 42 xenografts, 43,44 allografts, 26,41,45,46 autologous grafts, 23,26,41,45–48 and combinations thereof 38,45,49–56 yielding similar results with percentage bone gain ranging between 62% and 139%. Regarding the time of implant placement, both simultaneous 23,26,38,41,42,44,45,48,52 and staged approaches 23,41,43,45–47,49–56 were shown to be effective in yielding vertical regeneration.…”

“…Nevertheless, even though the occurrence of membrane exposure is rather frequent (approximately 12%), the percentages of failures reported in the literature are low. 26,41,43,45,46,48,50,54,55,[58][59][60]63,65,66 Simion et al, 26 using expanded polytetrafluoroethylene membranes, achieved regenerations of roughly 57% and 128% of the original defect in exposed and nonexposed sites, respectively. Similarly, Beitlitum et al, 58 using a cross-linked collagen membrane, found that membrane exposure led to approximately 50% less bone regeneration.…”

“…Data regarding the long‐term stability of the peri‐implant bone are rather scarce in literature and mainly coming from retrospective case series 23,26,37,42–45,48,50,55,63,65,78,79 (Table 2). Concerning non‐resorbable membrane, most short‐term studies (up to 12 months) report a mean marginal bone loss up to approximately 1 mm during the first year of loading 23,43,45,55,78,79 . A preclinical trial suggested that, after membrane removal, bone is subjected to resorption 80 .…”

“…nerve is exposed should not be treated with bone grafts placed directly on the exposed nerve, including guided bone regeneration. xenografts, 43,44 allografts, 26,41,45,46 autologous grafts, 23,26,41,[45][46][47][48] and combinations thereof 38,45,[49][50][51][52][53][54][55][56] yielding similar results with percentage bone gain ranging between 62% and 139%. Regarding the time of implant placement, both simultaneous 23,26,38,41,42,44,45,48,52 and staged approaches 23,41,43,[45][46][47][49][50][51][52][53][54][55][56] were shown to be effective in yielding vertical regeneration.…”

“…xenografts, 43,44 allografts, 26,41,45,46 autologous grafts, 23,26,41,[45][46][47][48] and combinations thereof 38,45,[49][50][51][52][53][54][55][56] yielding similar results with percentage bone gain ranging between 62% and 139%. Regarding the time of implant placement, both simultaneous 23,26,38,41,42,44,45,48,52 and staged approaches 23,41,43,[45][46][47][49][50][51][52][53][54][55][56] were shown to be effective in yielding vertical regeneration. However, a recent study of Urban et al 54 demonstrated that when using polytetrafluoroethylene membranes there is an increased probability of incomplete bone regeneration by 2.5 times for each millimeter of regeneration needed; hence, a simultaneous approach in a deep defect might result in an increased risk of implant deh...…”