Effect of mandibular residual ridge regularization on peri-implant wound healing when narrow diameter implants are used as overdenture retainers

Abstract

Statement of problemAlveolar ridge regularization involves the smoothing and minimal reduction of rough alveolar bone ridge to achieve adequate bone thickness around the implant. The effect of this procedure on peri-implant health is unclear. PurposeThe purpose of this clinical study was to evaluate whether bone regularization affects the clinical and biological parameters of peri-implant health when narrow diameter implants are placed as mandibular implant overdenture retainers during initial healing and after occlusal loading. Material and methodsThe need for mandibular ridge regularization in the anterior mandibular region was analyzed before the placement of 2 implants (2.9×10 mm, Facility; Neodent) in 21 participants provided with mandibular overdentures. Primary stability was measured by the insertion torque and implant stability quotient (ISQ). Clinical and biological evaluations measuring the plaque index, presence of calculus, probing depth, bleeding on probing index, gingival index, secondary stability (ISQ), and interleukine-1β (IL-1β) and tumor necrosis factor-α (TNF-α) concentrations in peri-implant crevicular fluid were measured during osseointegration on days 7, 15, 30, 60, and 90 and after loading on day 180 after implant placement. Multilevel mixed-effects linear regression analysis and the Kaplan–Meier test were used to analyze the data (α=.05). ResultsThe ISQ values showed significant differences on days 7 (P<.001) and 15 (P=.002) with higher values and on day 180 (P=.008) with a lower value compared with the baseline value in the ridge regularization group. Additionally, a significant decrease in probing depth was observed on days 60 (P=.008) and 180 (P=.027) compared with that on day 15 after implant placement. In the nonridge regularization group, significant decreases in probing depth were observed on days 30 and 180. Moreover, TNF-α levels in this group were significantly lower on days 30 (P=.001), 60, 90, and 180 (P<.001) when compared with the value on day 7 (P<.001). The ridge regularization group presented with significant differences in TNF-α and IL-1β levels on days 60 (P=.004) and 30 (P=.007), respectively, when compared with the values on day 7. The ISQ and probing depth in the ridge regularization group were associated with changes in TNF-α and IL-1β levels; furthermore, bone type, duration of edentulism, and mandibular bone atrophy were correlated with the clinical outcomes and TNF-α release. The implant survival rate was 67% in the nonridge regularization group and 100% in the ridge regularization group. ConclusionsMandibular ridge regularization appeared to be beneficial for peri-implant healing during the early stages and after 3 months of occlusal loading in patients with an atrophic ridge, prolonged time since edentulism, and poor bone quality.