Luca Cordaro

Maxillary sinus grafting with Bio‐Oss® or Straumann® Bone Ceramic: histomorphometric results from a randomized controlled multicenter clinical trial

INTRODUCTION This investigation was designed to compare the histomorphometric results from sinus floor augmentation with anorganic bovine bone (ABB) and a new biphasic calcium phosphate, Straumann Bone Ceramic (BCP). MATERIALS AND METHODS Forty-eight maxillary sinuses were treated in 37 patients. Residual bone width was > or =6 mm and height was > or =3 mm and <8 mm. Lateral sinus augmentation was used, with grafting using either ABB (control group; 23 sinuses) or BCP (test group; 25 sinuses); sites were randomly assigned to the control or test groups. After 180-240 days of healing, implant sites were created and biopsies taken for histological and histomorphometric analyses. The parameters assessed were (1) area fraction of new bone, soft tissue, and graft substitute material in the grafted region; (2) area fraction of bone and soft tissue components in the residual alveolar ridge compartment; and (3) the percentage of surface contact between the graft substitute material and new bone. RESULTS Measurable biopsies were available from 56% of the test and 81.8% of the control sites. Histology showed close contact between new bone and graft particles for both groups, with no significant differences in the amount of mineralized bone (21.6+/-10.0% for BCP vs. 19.8+/-7.9% for ABB; P=0.53) in the biopsy treatment compartment of test and control site. The bone-to-graft contact was found to be significantly greater for ABB (48.2+/-12.9% vs. 34.0+/-14.0% for BCP). Significantly less remaining percentage of graft substitute material was found in the BCP group (26.6+/-5.2% vs. 37.7+/-8.5% for ABB; P=0.001), with more soft tissue components (46.4+/-7.7% vs. 40.4+/-7.3% for ABB; P=0.07). However, the amount of soft tissue components for both groups was found not to be greater than in the residual alveolar ridge. DISCUSSION Both ABB and BCP produced similar amounts of newly formed bone, with similar histologic appearance, indicating that both materials are suitable for sinus augmentation for the placement of dental implants. The potential clinical relevance of more soft tissue components and different resorption characteristics of BCP requires further investigation.

Two-year prospective clinical comparison of immediate replacement vs. immediate restoration of single tooth in the esthetic zone

AIM To compare the immediate restoration of single implants in the esthetic zones performed on implants placed immediately after tooth extraction or 8 weeks later (immediate replacement vs. immediate restoration). METHODS Sixteen patients (10 women and 6 men) with a mean age of 35 years (ranging from 21 to 49 years old) were treated from 2004 to 2005 for single-tooth replacement in the upper arch. The patients were randomly divided into two groups: in the test group patients received implants placed and restored (non-occlusal loading) at the time of tooth extraction; in the control group implants were placed 8 weeks after tooth extraction and immediately restored. All the patients received tapered effect (TE) implants from the Straumann Dental Implant System. The following parameters were evaluated at the moment of provisional restoration (within 48 h after implant placement) and at the 2 years follow-up visit: marginal bone resorption, papilla index, position of the mucosal margin. The implant stability quotient was measured at the moment of implant placement and at the moment of the delivery of the definitive restoration. RESULTS No statistically significant differences were found in any of the studied parameters between the test and the control groups (P>0.05). The implant stability quotient values between the test and control groups were significant (P<0.05) at the moment of implant placement but were no more significant at the loading of the definitive restoration (P>0.05). CONCLUSION The results of the present study suggest that immediate replacement without functional loading may be considered a valuable therapeutic option for selected cases of single-tooth replacement in the esthetic area when TE implants are used. Implant stability at the moment of implant placement is slightly inferior in the immediate replacement group, but it does not affect the treatment result.

Clinical outcome of submerged vs. non‐submerged implants placed in fresh extraction sockets

AIM The aim of this study was to compare the clinical outcome of submerged vs. non-submerged tapered implants placed into fresh extraction sockets. MATERIALS AND METHODS A prospective, controlled, multicenter, randomized, clinical trial has been performed in two centers in Rome and Torino (Italy). Thirty healthy patients were recruited according to the following inclusion criteria: need for an immediate post extraction implant, ages between 18 and 70, horizontal defect depth <2 mm, smokers <10 cigarettes/day and absence of any circumstance or condition that could represent contraindications to implant surgery. The patients were randomly allocated to submerged or non-submerged treatment groups immediately after flap elevation and tooth extraction. Submerged implants were exposed 8 weeks after the first surgery; all implants were loaded with provisional restorations 12 weeks after the first surgery and with definitive restoration 12 weeks thereafter. Clinical and radiographic parameters were evaluated at baseline, at implant loading and at the 1-year follow-up visit. RESULTS The results showed statistically significant differences between the two groups in the mean value of keratinized tissue (KT) height after surgery that was significantly reduced for submerged implants when compared with transmucosal implants (mean reduction of KT at year follow-up: T group 0.2 mm, S group 1.3 mm; P=0.007). CONCLUSION Similar outcomes were found for submerged and non-submerged implants placed in fresh extraction sockets with a horizontal peri-implant defect smaller than 2 mm, except for a reduction of KT in the submerged group. Either with a submerged or a non-submerged procedure, 1 mm of mean soft tissue recession is seen after 1 year when compared with the pre-extraction situation.

Effect of bovine bone and collagen membranes on healing of mandibular bone blocks: a prospective randomized controlled study

AIM The aim of the present study was to evaluate if the use of deprotenized bovine bone mineral (DBBM) and collagen barrier membranes (CM) in combination with mandibular bone block grafts could reduce bone block graft resorption during healing. METHODS A prospective randomized controlled study has been designed. Twenty-two ridges presenting horizontal alveolar deficiency (crest width <4 mm) and at least two adjacent missing teeth were included in the study. In the control group, one or multiple mandibular blocks were used to gain horizontal augmentation of the ridge. In the test group, DBBM granules were added at the periphery and over the graft. The reconstructions were covered by two layers of CM. Implants were placed 4 months after grafting. Direct measurements of crest width were performed before and immediately after bone augmentation, and immediately before implant placement. RESULTS Statistical analysis showed no significant differences in crest width between test and control groups at baseline and immediately after grafting. Mean augmentation at first surgery in the test group was 4.18 vs. 4.57 mm in the control group. Final gain obtained at the time of implant placement was 3.93 mm in the test and 3.67 mm in the control groups. The difference in mean graft resorption between test and control sites was statistically significant (0.25 mm in the test group vs. 0.89 mm in the control group, P=0.03). Complications seem to occur more often in the test group (complications recorded in three cases in the test group vs. one complication recorded in the control group). In all cases, implants could be placed in the planned sites and a total of 55 implants were placed (28 in the test group and 27 in the control group). All implants could be considered successfully integrated at the 24-month follow-up visit. CONCLUSION The results from this study showed that the addition of bovine bone mineral and a CM around and over a mandibular bone block graft could minimize graft resorption during healing. On the other hand, the use of bone substitutes and barrier membranes in combination with block grafts increased the frequency of complications and the difficulty of their management.

Submerged and transmucosal healing yield the same clinical outcomes with two‐piece implants in the anterior maxilla and mandible: interim 1‐year results of a randomized, controlled clinical trial

OBJECTIVES To test whether or not transmucosal healing at two-piece implants is as successful as submerged placement regarding crestal bone levels and patient satisfaction. MATERIAL AND METHODS Adults requiring implants in the anterior maxilla or mandible in regions 21-25, 11-15, 31-35 or 41-45 (WHO) were recruited for this randomized, controlled multi-center clinical trial of a 5-year duration. Randomization was performed at implantation allowing for either submerged or transmucosal healing. Final reconstructions were seated 6 months after implantation. Radiographic interproximal crestal bone levels and peri-implant soft tissue parameters were measured at implant placement (IP) (baseline), 6 and 12 months. Patient satisfaction was assessed by a questionnaire. A two-sided t-test (80% power, significance level α=0.05) was performed on bone-level changes at 6 and 12 months. RESULTS One hundred and twenty-seven subjects were included in the 12-month analysis (submerged [S]: 52.5%, transmucosal [TM]: 47.2%). From IP to 6 months, the change in the crestal bone level was -0.32 mm (P<0.001) for the S group and -0.29 mm (P<0.001) for the TM group. From IP to 12 months, bone-level changes were statistically significant in both groups (S -0.47 mm, P<0.001; TM -0.48 mm, P<0.001). The mean differences of change in the bone levels between the two groups were not statistically significant at either time point, indicating the equivalence of both procedures. For both groups, very good results were obtained for soft tissue parameters and for patient satisfaction. CONCLUSIONS Transmucosal healing of two-piece implants is as successful as the submerged healing mode with respect to tissue integration and patient satisfaction within the first 12 months after IP.

Clinical and Radiologic Outcomes after Submerged and Transmucosal Implant Placement with Two‐Piece Implants in the Anterior Maxilla and Mandible: 3‐Year Results of a Randomized Controlled Clinical Trial

PURPOSE The aim of this investigation was to evaluate the 3-year outcomes regarding crestal bone level, clinical parameters, and patient satisfaction, following submerged and transmucosal implant placement for two-piece implants in the anterior maxilla and mandible. MATERIALS AND METHODS Patients requiring dental implants for single-tooth replacement in the anterior maxilla or mandible were enrolled in a randomized, controlled, multicenter clinical trial. The implants were randomized at placement to either submerged or transmucosal healing, with final restorations placed after 6 months. Radiographic and clinical parameters were recorded after 1, 2, and 3 years; a questionnaire was also used to assess patient satisfaction. A two-sided, unpaired T-test (significance level p ≤ .05) was used to statistically evaluate the differences between the two groups. RESULTS A total of 106 patients were included in the 3-year analysis. The mean change in crestal bone level from implant placement to 3 years was 0.68 ± 0.98 mm (p < .001) and 0.58 ± 0.77 mm (p < .001) in the submerged and transmucosal groups, respectively; the differences between the groups were not significant. Clinical parameters remained stable throughout the study, with no significant differences between the groups, and patient satisfaction was good or excellent for over 90% of subjects in both groups. CONCLUSIONS The results demonstrate excellent clinical and radiographic conditions after 3 years for implants supporting single-tooth restorations, regardless of whether a submerged or transmucosal surgical technique was used.

Digital technologies to support planning, treatment, and fabrication processes and outcome assessments in implant dentistry: summary and consensus statements: the 4th EAO consensus conference 2015

OBJECTIVE The task of this working group was to assess the existing knowledge in computer-assisted implant planning and placement, fabrication of reconstructions applying computers compared to traditional fabrication, and assessments of treatment outcomes using novel imaging techniques. MATERIAL AND METHODS Three reviews were available for assessing the current literature and provided the basis for the discussions and the consensus report. One review dealt with the use of computers to plan implant therapy and to place implants in partially and fully edentulous patients. A second one focused on novel techniques and methods to assess treatment outcomes and the third compared CAD/CAM-fabricated reconstructions to conventionally fabricated ones. RESULTS The consensus statements, the clinical recommendations, and the implications for research, all of them after approval by the plenum of the consensus conference, are described in this article. The three articles by Vercruyssen et al., Patzelt & Kohal, and Benic et al. are presented separately as part of the supplement of this consensus conference.

Implant‐supported single tooth restoration in the aesthetic zone: transmucosal and submerged healing provide similar outcome when simultaneous bone augmentation is needed

AIM The aim of this study was to compare the clinical outcomes after 2 years with bone level implants placed to restore a single missing teeth that needed simultaneous augmentation and were treated with a transmucosal or submerged approach. METHODS This study analyzed a subset of patients included in an ongoing prospective multicenter randomized clinical trial (RCT) involving12 centers where patients were to be followed-up to 5 years after loading. Of the 120 implants that were placed in the original study, and randomly assigned to submerged or non-submerged healing, 52 needed simultaneous augmentation (28 women patients and 24 men patients, between 23 and 78 years of age). Twenty-seven of them received implants with submerged healing (AuS), while in 25 patients the implants were inserted with a non-submerged protocol (AuNS). At the 2-year follow-up visit, radiographic crestal bone level changes were recorded as well as soft tissue parameters included Pocket probing depth (PPD), bleeding on probing (BoP) and clinical attachment level (CAL) at teeth adjacent to the implant site. RESULTS After 2 years a small amount of bone resorption was found in both groups (0.37 ± 0.49 mm in the AuS group and 0.54 ± 0.76 in the AuNS group; P < 0.001). There was no statistically significant difference between AuS Group and AuNS group for PPD (2.5 vs. 2.4 mm), BOP (BOP + sites: 8.8% vs. 11.5%) and CAL (2.8 vs. 2.4 mm) at the 2-year follow-up visit. CONCLUSIONS When a single implant is placed in the aesthetic zone in conjunction with bone augmentation for a moderate peri-implant defect, submerged and transmucosal healing determine similar outcome, hence there is no need to submerge an implant in this given clinical situation.

Fracture and displacement of lingual cortical plate of mandibular symphysis following bone harvesting: case report.

This article describes a unique complication after chin bone harvesting. The complication consisted of fracture and posterior displacement of the lingual cortical plate that did not occur at the time of the operation but during the healing phase. The bone was harvested for a bilateral sinus lift procedure. Diagnosis was made by chance with the aid of a postoperative CT scan that was taken to study the sinus area. The mandibular scans revealed a bony fragment 2 to 4 mm in width and 3 cm in length fractured and displaced 1 cm posteriorly. This bony fragment was pedicled to the geniohyoid and genioglossus muscles. The patient was asymptomatic, and no treatment was carried out. The patient is still symptom-free 16 months after the initial diagnosis of the fracture.

Reconstruction of the moderately atrophic edentulous maxilla with mandibular bone grafts

BACKGROUND Mandibular bone grafts are used for alveolar reconstruction in partially edentulous patients. Few reports describe the use of mandibular bone for total maxillary reconstruction. AIM To describe indications to the use of extensive mandibular bone grafts for maxillary reconstructions in edentulous patients. METHODS A retrospective evaluation of a group of patients with edentulous resorbed maxillae reconstructed with mandibular bone grafts in preparation for implant placement was performed. The studied cohort consisted of 15 patients who were treated with mandibular onlay blocks and sinus augmentation with mandibular bone in an outpatient setting under local anesthesia (MG). This approach was chosen when residual bone height in the anterior maxilla was at least 8 mm combined with posterior vertical deficiency and anterior horizontal defects. Success and survival rates of the implants and prostheses together with the achievement of the planned prosthetic plan were recorded. Patients also performed an evaluation of the outcome with the aid of Visual Analog Scales. Mean follow-up time was 19 months after prosthesis delivery. RESULTS No major surgical complications occurred at recipient or donor sites. A total of 81 implants were inserted, and survival and success rates were 97.6% and 93%, respectively. Planned prostheses could be delivered to all patients (eight overdentures and seven fixed dental prostheses). CONCLUSIONS With the limitations of the present clinical study, it can be stated that edentulous maxillae with a moderate atrophy may be successfully augmented with mandibular bone grafts in an outpatient setting under local anesthesia and e.v. sedation. This is the case when posterior maxillary deficiency is combined with horizontal defects, but with a residual height of 8 mm or more in the anterior maxilla. When the residual anterior bone height is less than 8 mm, or when the inter-arch discrepancy needs to be corrected with an osteotomy, extraoral bone harvesting needs to be considered.