Clinical and radiographic comparison of implants in regenerated or native bone: 5‐year results

Abstract

PURPOSE: The aim of this study was to test whether or not implants associated with bone regeneration show the same survival and success rates as implants placed in native bone in patients requiring both forms of therapy. MATERIAL AND METHODS: Thirty-four patients (median age of 60.3 years, range 18-77.7 years) had been treated 5 years before the follow-up examination. Machined screw-type implants were inserted following one of two surgical procedures: (1) simultaneously with a guided bone regeneration (GBR) procedure, which involved grafting with xenogenic bone substitute material, autogenous bone or a mixture of the two and defect covering with a bio-absorbable collagen membrane (test) and (2) standard implantation procedure without bone regeneration (control). For data recording, one test and one control implant from each patient were assessed. Examination included measurements of plaque control record (PCR), probing pocket depth (PPD), bleeding on probing (BOP), width of keratinized mucosa (KM), frequency of situations with supra-mucosal location of the crown margin, implant survival assessment and radiographic examination. Radiographs were digitized to assess the marginal bone level (MBL). Differences between groups were tested using the one-sample t-test. The estimation of survival rate was based on Kaplan-Meier analysis. RESULTS: The follow-up period of the 34 GBR and 34 control implants ranged from 49 to 70 months (median time 57 months). Cumulative survival rates reached 100% for the GBR group and 94.1% for the control group without statistical significance. No statistically significant differences for clinical and radiographic parameters were found between the two groups regarding PCR, BOP, PPD, KM and MBL. CONCLUSION: The present study showed that, clinically, implants placed with concomitant bone regeneration did not performed differently from implants placed into native bone with respect to implant survival, marginal bone height and periimplant soft tissue parameters. simultaneously with a GBR procedure, which involved grafting with xenogenic bone substitute material, autogenous bone or a mixture of the two and defect covering with a bio-absorbable collagen membrane (test); 2. standard implantation procedure without bone regeneration (control). For data recording one test and one control implant from each patient were assessed. Examination included measurements of plaque control record (PCR), probing pocket depth (PPD), bleeding on probing (BOP), width of keratinized mucosa (KM), frequency of situations with supra-mucosal location of the crown margin, implant survival assessement and radiographic examination.Radiographs were digitized to assess the marginal bone level (MBL). Differences between groups were tested using the one sample t test. The estimation of survival rate was based on Kaplan-Meier analysis. Results:The follow-up period of the 34 GBR and 34 control implants ranged from 49 to 70 months (median time 57.0 months). Cumulative survival rates reached 100% for the GBR group and 94...

Bone regeneration using particulate grafts: An update

“…Indications of particulate grafts Particulate grafts fundamentally have been used in cases of small or peri-implant bone defects such as dehiscences and fenestrations, with the possibility of associating guided bone regeneration techniques (8)(9)(10)14). However, when the bone defect is moderate, and the aim is to secure vertical or horizontal increments, some authors prefer block cortico-cancellous bone in particulate form, using the Tessier osseous microtome or bone mill (12,13).…”

“…Surgical procedure Five studies (10,12,(14)(15)(16)) used a combination of autograft with xenograft, hydroxyapatite or homologous bone. In the remaining 8 studies a single type of graft was used: autologous bone (8,10,13,14), homologous bone (11,14), bovine bone (10,18,19) or hydroxyapatite (17). In two studies (13,15) the intraoral autologous grafts were obtained from the retromolar region, while in one publication the graft was harvested from the mandibular ramus (16).…”

“…The recommendation is a minimum of 4-5 mm of residual bone for graft and implant placement in a single surgical step (9). In 5 studies (8,10,14,15,18) the implants were placed at the same time as the grafts. Von Arx and Wallkamm (8), Blanco et al (14) and Benić et al (10) treated cases of dehiscences and fenestrations, while Simion et al (15) and Canullo and Malagnino (18) treated patients with vertical crest defects.…”

“…In relation to horizontal mandibular augmentation, Block and Degen (11) placed the implants after a four-month healing interval. In the studies involving dehiscences or fenestrations (8,10,14), the particulate grafts were placed with the implants in the same surgical step. In 5 studies (12,13,15,17,18) biopsies were obtained of the implant receptor bone at the end of the graft healing period, and the histological study confirmed an adequate bone structure for implant placement.…”

“…In this context, bone grafts are an option for securing adequate bone volume and morphology (6,7). Particulate grafts have been used in cases of small or peri-implant defects such as dehiscences and fenestrations, and combination with guided bone regeneration (GBR) techniques is also possible (8)(9)(10). When the bone defect is moderate, some authors have used block cortico-cancellous bone in particulate form to secure vertical or horizontal increments of the alveolar process (11)(12)(13).…”