Orthodontic Extrusion vs. Surgical Extrusion to Rehabilitate Severely Damaged Teeth: A Literature Review.

The need to rehabilitate severely compromised teeth is frequent in daily clinical practice. Tooth extraction and replacement with dental implant represents a common treatment choice. However, the survival rate for implants is inferior to teeth, even if severely damaged but properly treated. In order to reestablish a physiological supracrestal tissue attachment of damaged teeth and to arrange an efficient ferrule effect, three options can be considered: crown lengthening, orthodontic extrusion and surgical extrusion. Crown lengthening is considered an invasive technique that causes the removal of part of the bony support, while both orthodontic and surgical extrusion can avoid this inconvenience and can be used successfully in the treatment of severely damaged teeth. The aim of the present narrative review is to compare advantages, disadvantages, time of therapy required, contraindications and complications of both techniques.

The Why, What, How and What if-The method to present your research and clinical cases.

BACKGROUND: During the fourth Summer Camp (SC) held by the European Association of Osseointegration (EAO), 20 junior representatives from various European and non-European universities and associations were selected to partake in oral presentation and communication skill development. AIMS: The aim of the EAO Summer Camp (EAO SC) was to identify new methods of enhancing participants' abilities to engage, influence and lead in a professional environment, on both a clinical and scientific level. MATERIALS AND METHODS: Four different groups were assigned to discuss one of two topics: (1) an Implant Register and (2) Digital Dentistry. The method that was used during the EAO SC, for training presentation skills, was the 4MAT learning model. The 4MAT learning model is a framework for creating an engaged, dynamic and more involved style of training by accurately visualizing the learning process that each learner goes through. RESULTS AND CONCLUSIONS: All four groups, including each participant, presented outcomes in the format of 4MAT learning model answering four key questions, the Why, the What, the How and the What if. After the event, each group prepared a written summary of the thought processes. The outcome of the summer camp, for the chosen participants, was gaining skills to engage and influence in a professional environment, both clinically and scientifically. It was also expected from participants to share gained knowledge in their own respective environments after the EAO Summer Camp had ended. In conclusion, most of participants gained a valuable insight into presentation skills and also demonstrated their enthusiasm by presenting their experience at universities, institutes and clinics.

Full Digital Workflow for the Treatment of an Edentulous Patient with Guided Surgery, Immediate Loading and 3D-Printed Hybrid Prosthesis: The BARI Technique 2.0. A Case Report.

PURPOSE: To describe a technique intended to transfer of the intermaxillary and occlusal relationships in a fully digital environment from a complete denture to an implant-supported 3D-printed hybrid prosthesis (an acrylic resin complete fixed dental prosthesis supported by implants). METHODS: In edentulous cases, the physiological mandibular position should be determined before the immediate loading procedures. In some cases, the use of interim removable prostheses for a few weeks could be useful to test the new occlusion in centric relation and to verify the prosthetic project. When the correct intermaxillary relationships are achieved, it is difficult to transfer them from the provisional to the final prostheses, as impressions or scans of edentulous arches do not have reference points for intermaxillary records. This paper presents a complex case and the technique used to transfer information from a complete denture to an implant-supported prosthesis with a digital workflow. A prosthetic stent has been used to scan the edentulous mandibular arch and to record the intermaxillary relation. RESULTS: The delivery of the hybrid implant-supported prostheses was carried out with no problems and minimal occlusal adjustments. The patient was extremely satisfied with the treatment and the situation remained stable at the 1-year follow up. CONCLUSIONS: The approach described in the present article predictably maintains prosthetic information and allows the delivery of a final implant-supported restoration with the same occlusal relationship as the one tested with the provisional diagnostic dentures.

Biomechanical aspects: Summary and consensus statements of group 4. The 5th EAO Consensus Conference 2018.

OBJECTIVES: The aim of the present publication was to report on the EAO Workshop group-4 discussions and consensus statements on the five reviews previously prepared. These reviews provided the scientific evidence on the effect of crown-to-implant ratio, on reconstructions with cantilevers in fully and partially edentulous patients, on biological and technical complications of tilted in comparison with straight implants, and on the effects of osseointegrated implants functioning in a residual dentition. MATERIAL AND METHODS: The group discussed, evaluated, corrected where deemed appropriate, and made recommendations to the authors regarding the following five reviews submitted: (a) Is there an effect of crown-to-implant ratio on implant treatment outcomes?; (b) Implant-supported cantilevered fixed dental rehabilitations in fully edentulous patients; (c) and in partially edentulous patients; (d) Biological and technical complications of tilted implants in comparison with straight implants supporting fixed dental prostheses; (e) What are the adverse effects of osseointegrated implants functioning among natural teeth of a residual dentition? Based on the five manuscripts and the discussion among the group as well as the plenum members, the major findings were summarized, consensus statements were formulated, clinical recommendations were proposed, and areas of future research were identified. RESULTS: Crown-to-implant ratios ranging from 0.9 to 2.2 did not influence the occurrence of biological or technical complications also in single-tooth restorations. Reconstructions with cantilevers for the rehabilitation of fully and partially edentulous jaws showed high implant and reconstruction survival rates. In contrast, the rate of complications-in particular associated with veneering material-was high during the observation period of 5-10 years. The data reported were primarily derived from studies with high risk of bias. The data for single-implant reconstructions were small. There was no evidence that distally tilted implants were associated with higher failure rates and increased amounts of marginal bone loss. The data supporting these findings, however, were at high risk of bias and frequently incompletely reported. Frequent positional changes occurred between the natural teeth and the implant-supported restorations. These changes were more pronounced in younger individuals, and even though they were reduced with age, they still occurred in adult patients. Even though these changes were frequent, potential implications for the patient are unclear. CONCLUSIONS: The use of single-tooth restorations with crown-to-implant ratio in between 0.9 and 2.2 may be considered a viable treatment option. Multiunit reconstructions with cantilevers are a viable treatment option in fully and partially edentulous patients. Clinicians and patients should be aware, however, that complications are frequent and primarily related to resin material used for veneering. There is some evidence that tilting an implant does affect stability of the implant and the surrounding bone. Treatment options to tilted implants should carefully be considered, as the effect on soft tissues and on prosthesis behavior is poorly reported for tilted implants. Positional changes in the dentition in relation to implant-supported restorations occur frequently. The patient should be informed about the possible need for a treatment related to these changes in the long term.

Guidelines for development of Implant Dentistry in the next 10 years regarding innovation, education, certification, and associations.

BACKGROUND: During the third Summer Camp of European Association of Osseointegration (EAO), 40 junior representatives from various European societies and associations were brought together to discuss and explore the following topics in Implant Dentistry in the next 10 years: (I) certification, (II) societies and associations, (III) continuing education, and (IV) innovations. AIMS: The aims of all working groups were to identify and outline the present situation in the area of the selected topic and to propose improvements and innovations to be implemented in the following 10 years. MATERIALS AND METHODS: Four different groups were assigned randomly to one of the four working units. The method to discuss the selected topics was World Cafè. The summaries of four topics were then given to all participants for peer review. RESULTS AND CONCLUSIONS: All four groups presented the conclusions and guidelines accordingly: (I) The recognition for Implant Dentistry and accreditation of training programs would lead to an improvement of the quality of care to the benefit of the patients; (II) Dental associations and societies have to continuously improve communication to meet needs of dental students, professionals, and patients (III) European Dental Board should be installed and become responsible for continue dental education; (IV) dental engineering, peri-implant diseases, and digital workflow in dentistry currently have limited tools that do not guarantee predictable results.

Digital cross-mounting: A new opportunity in prosthetic dentistry.

The prosthodontic management of complex rehabilitations requires several stages of treatment including one or more provisional restorations. The design and adjustments of the provisional are made to achieve an optimal functional and esthetic outcome for the patient. However, the adjustments needed are both time and cost consuming. Therefore, once a satisfactory provisional is made, the information should not be lost during the following stages of treatment. The purpose of this clinical case is to illustrate "digital cross-mounting," a procedure used to precisely transfer information from the provisional to the final fixed rehabilitation in a digital workflow.

Therapeutic concepts and methods for improving dental implant outcomes. Summary and consensus statements. The 4th EAO Consensus Conference 2015.

BACKGROUND: Different therapeutic concepts and methods have been proposed for improving dental implant outcomes in three specific clinical situations: (i) the fresh extraction socket with alveolar ridge preservation protocols; (ii) the posterior maxilla with limited bone height with either the placement of regular-sized implants after sinus elevation and grafting or short dental implants and; (iii) the posterior mandible with limited bone height with either vertical bone augmentation and placement of implants or short dental implants. MATERIALS AND METHODS: Three systematic reviews, based on randomized and controlled clinical trials have evaluated the efficacy of these different therapeutic modalities in terms of dental implant outcomes. RESULTS AND CONCLUSIONS: Interventions aimed for alveolar ridge preservation have shown efficacy in terms of allowing the placement of dental implants and for reducing the need of further augmentation procedures at implant placement. Both therapeutic options, the placement of implants after sinus elevation and grafting or short dental implants, were valid alternatives in the treatment of the posterior maxilla with deficient bone availability, although short implants resulted in fewer complications. Similarly, the placement of implants in vertically augmented bone rendered comparable outcomes with those of short implants in the treatment of the posterior mandible, but short implants resulted in fewer complications.

The BARI technique: a new approach to immediate loading.

When dealing with full-arch rehabilitation, the provisional phase is important in order to define the correct occlusal, intermaxillary, and esthetic relationships for each individual patient. In these cases, it is difficult to transfer this information to the final restorations. Several techniques have been developed to transfer the information from tooth- or implant-supported fixed provisionals to the definitive rehabilitations. The present article describes a technique proposed by the authors to transfer the information from a removable prosthesis to an implant-supported restoration.

Retrospective analysis of 26 complete-arch implant-supported monolithic zirconia prostheses with feldspathic porcelain veneering limited to the facial surface.

STATEMENT OF PROBLEM: Monolithic zirconia prostheses on teeth or implants have been proposed in recent years as a potential treatment. To date, limited data regarding the outcomes of these prostheses have been presented and are mainly based on limited sample size and short-term follow-up. Data on complete-arch monolithic zirconia prostheses are relatively scarce. PURPOSE: The purpose of this retrospective study was to evaluate the clinical performances of 26 implant-supported, complete-arch, monolithic zirconia restorations with facial feldspathic porcelain veneers for the rehabilitation of completely edentulous patients. MATERIAL AND METHODS: All patients' charts from 2 private practices from 2010 to 2013 were reviewed. Patients rehabilitated with a complete-arch implant-supported monolithic zirconia prostheses were included in the study. Several parameters were recorded so as to evaluate the outcome of these rehabilitations: implant survival and success rates, prosthesis survival rate, interproximal bone loss, periimplant probing depth, and bleeding on probing. The number and type of prosthetic complications were also recorded. Data were analyzed with descriptive statistics. RESULTS: Eighteen patients were treated with a total of 26 complete-arch fixed prostheses. The mean follow-up time was 20.9 months (SD 13.6; range, 10 to 36 months). In total, 154 implants were placed supporting 309 retainers and pontics. The implant survival rate was 100% and the success rate was 94.8%. Mean bone loss was 0.66 mm (SD 0.59 mm). Mean probing depth was 3.4 mm (SD 0.92 mm). Bleeding on probing was positive in 19% of probing sites. The prosthesis survival rate was 100%. CONCLUSIONS: The results of this retrospective evaluation showed that monolithic zirconia restorations with facial porcelain veneer provided satisfactory clinical performance and suggest that these rehabilitations are a viable treatment option for completely edentulous patients.

Computer-assisted flapless implant surgery in edentulous elderly patients: a 2-year follow up.

OBJECTIVE: The rehabilitation of edentulous mandibles with implant-supported overdentures is a state-of-the-art contemporary implant treatment. Computer-assisted flapless surgery is associated with decreased chairside treatment time, as well as significant reduction in patient postoperative morbidity and discomfort. The aim of this study was to evaluate the protocol of computer-guided surgery in the treatment of edentulous mandibles with overdentures supported by four intraforaminal implants and retained by Locator® attachments in elderly patients, both from a clinician's and a patient's perspective, as well as to assess the stability of the results in a 2-year period. METHOD AND MATERIALS: 15 patients presenting edentulous mandibles and discomfort while wearing conventional overdentures were enrolled in the study. Careful presurgical and computer-assisted 3D treatment planning was performed. Patients were treated with four intraforaminal implants using a computer-assisted flapless approach. All patients were prosthetically rehabilitated with overdentures. Clinical parameters such as peri-implant probing depth (PPD), Plaque Index (PI), and bleeding on probing (BOP) were evaluated. Patients' perceptions regarding the outcome were assessed on visual analog scales (VAS). RESULTS: Out of 15 patients consecutively included in the study, only 10 patients could be treated with the designed protocol. A total of 40 Camlog implants were placed. No implant was lost over a 2-year period. BOP was negative in 82% of sites; mean PPD was 2.34 mm; 8 of the 40 implants showed the absence of keratinized tissue on the lingual or the vestibular aspect. The VAS score of 9.9 demonstrated the satisfaction of the patients. CONCLUSIONS: Within the limitations of this study, the data demonstrate that in a significant number of cases this protocol could not be used for anatomical or technical reasons. In the cases where it could be used, the computer-assisted protocol appeared suitable for treating elderly patients with mandibular edentulism and restoring them with an overdenture in a minimally invasive way. The possibility of placing implants outside the borders of the keratinized tissue is relevant.

Rehabilitation of an edentulous atrophic maxilla with four unsplinted narrow diameter titanium-zirconium implants supporting an overdenture.

The edentulous maxilla is often affected by bone resorption, sometimes making it difficult to place standard diameter implants. Narrow diameter implants made of titanium-zirconium (Ti-Zr) alloy, which has superior mechanical properties compared with titanium, have been proposed for these difficult situations. This retrospective clinical observation reports the outcome of the use of reduced diameter implants made of Ti-Zr alloy supporting maxillary overdentures retained with locator abutments. The charts of all patients who received maxillary overdentures supported by four unsplinted implants from January 2009 to June 2010 at the Department of Periodontology and Prosthodontics, Eastman Dental Hospital, Rome, Italy, were reviewed. All patients treated with four narrow diameter Ti-Zr implants were selected for the present case series. Ten patients were found, six of whom received augmentation procedures. After 12 to 16 months of follow-up, no implants were lost, and only one implant showed bone resorption greater than 1.5 mm. Implants showed a success rate of 97.5% and a survival rate of 100%. All prostheses were successfully in function. The present case series showed promising results regarding the use of narrow diameter implants made of Ti-Zr supporting maxillary overdentures retained with locator abutments.

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.

Marginal discrepancies of Ni/Cr crowns for a soft tissue-level, trans-mucosal implant system.

OBJECTIVE: To examine the marginal fit of frameworks for implant-supported single crowns built with or without the use of prefabricated plastic copings. METHODS: Sixty premolar sized metal crown frameworks for cemented implant restorations were prepared by two separate dental laboratories. Twenty were prepared with the use of original plastic copings for burn-out (OPC), twenty without any prefabricated plastic coping (WPC), and finally twenty with modified plastic copings (MPC). Specimens were inspected at 100× magnification. Marginal discrepancies can emerge at the vertical level as marginal gaps (MG) or horizontal differences in the circumferential precision of the restorations (HEX). HEX and MG were recorded at 10 different points in each metal crown. The ANOVA test was performed to estimate if there were statistically significant differences between the two dental laboratories. ANOVA Test was also used between Groups OPC, WPC, and MPC to evaluate differences in the mean MG and HEX values. The Tukey's post hoc test was also performed to determine whether couples of data sets were different or not. RESULTS: No statistically significant differences regarding HEX and MG were found among the two dental laboratories. Significant differences were found among OPC, WPC, and MPC groups both for MG and HEX (P < 0.05). Tukey post hoc tests revealed that there were statistically significant differences (P-value < 0.05) in all pairs of groups and for both dimensions measured. The OPC group showed horizontal and vertical over-extension. The WPC group margins appeared vertically under-extended but horizontally over-extended. The WPC groups showed unpredictability of results in the vertical dimension. The MPC group margins demonstrated horizontal over-extension and appeared vertically slightly under-extended. The frameworks belonging to this group appeared the most precise in the vertical dimension. CONCLUSIONS: Casting Ni/Cr alloys without the use of prefabricated plastic components leads to unpredictable precision in the vertical marginal discrepancies. The use of plastic copings results in more predictable but horizontally and vertical over-extended margins when the snap-on mechanism is not removed properly after the casting due to the hardness of the Ni/Cr alloys. The removal of the snap-on mechanism after the wax-up and before casting (MPC group) results in more uniform and smaller vertical marginal discrepancies.

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.

Single unit attachments improve peri-implant soft tissue conditions in mandibular overdentures supported by four implants.

AIM: To evaluate the clinical performance as well as patients' and clinicians' satisfaction on two different prosthodontic retention systems for implant-overdentures in the mandible. METHODS: In this retrospective study, patients provided with four intraforaminal implants with at least 12 months of follow-up since overdenture delivery were evaluated. A total of 39 patients were treated either with Locator(®) attachment or with cad-cam milled bar. Clinical parameters such as Peri-implant Probing Depth (PPD), Plaque Index (PI), and Bleeding on Probing (BOP) were evaluated. Patients' and clinicians' perceptions regarding the outcome were assessed on visual analog scales (VAS). RESULTS: The mean follow-up was 13 months in the Locator(®) group and 18 months in the Bar group and no implants were lost. The Locator group showed better results for PPD, PI, and BOP values. Patients' satisfaction was high in both groups, whereas the clinicians found better hygienic conditions and soft tissue health in the Locator group. CONCLUSIONS: Although the patients' satisfaction was similar in both groups the Locator(®) system demonstrated better soft tissues scores because hygienic maintenance was more complicated around bars. This may increase the frequency of chronic inflammations around the implants.

Split-mouth comparison of a coronally advanced flap with or without enamel matrix derivative for coverage of multiple gingival recession defects: 6- and 24-month follow-up.

The aim of this study was to evaluate whether the use of enamel matrix derivative (EMD) improves clinical results of the coronally advanced flap (CAF) procedure in the treatment of multiple gingival recession defects. Ten patients presenting at least two adjacent buccal gingival recession defects affecting symmetric teeth on both sides of the maxilla were included in this study. Each set of multiple recession defects was assigned randomly to the test or control group. A bilateral simultaneous CAF procedure with vertical releasing incisions, with the adjunct of EMD for test sites, was performed. Clinical measurements (recession length, keratinized tissue, probing depth, and clinical attachment level) were assessed at baseline and 6 and 24 months after surgery by a blinded examiner. At the 6-month evaluation, both treatment procedures displayed good results with significant root coverage gain (CAF, 80.7% ± 20%; CAF + EMD, 82.8% ± 14%). A similar amount of relapse was noted at the 24-month evaluation when compared with the 6-month results (CAF, 71.0% ± 22%; CAF + EMD, 74.8% ± 16%). The use of EMD does not seem to significantly improve the results of the CAF procedure for root coverage in treatment of multiple recessions.

Mandibular bone harvesting for alveolar reconstruction and implant placement: subjective and objective cross-sectional evaluation of donor and recipient site up to 4 years.

AIM: To evaluate the long-term morbidity of intraoral bone harvesting from two different donor sites (mandibular symphysis or ramus) for bone augmentation procedures before or at the time of implant placement and to evaluate the success and the survival rates of implants placed in sites augmented with mandibular bone. METHODS: Seventy-eight patients who received mandibular bone grafts were recalled after 18-42 months follow-up (mean 29 months). The group consisted of 36 men and 42 women aged between 18 and 68 years old at the moment of augmentation surgery. Vitality of teeth adjacent to the harvesting sites was investigated. Soft tissue superficial sensory function was assessed by the Pointed-Blunt Test and the Two-Point-Discrimination Test. Implant health status was assessed measuring peri-implant probing depth and bleeding on probing. Implant survival and success rates were also calculated. In order to evaluate patients' perception of the morbidity of the procedures, the patients were asked to answer several questions by means of visual analogue scales (VAS). RESULTS: Only two teeth (out of 282) in the chin harvesting group needed root canal treatment after surgery. A higher frequency of minor temporary and permanent sensorial disturbances was found in the group of patients who received chin harvesting procedures (2.3% vs. 13%P=0.03), while pain during chewing and bleeding were more frequently recorded after ramus harvesting (9.8% vs. 0%P=0.03). No permanent anesthesia of any region of the skin was reported. Implants' survival and success rate were comparable to implants placed in bone reconstructed with other techniques and were not influenced by the choice of the donor site. Patient's perception regarding the morbidity of the procedures was very low and did not differ between ramus and chin harvesting groups (mean VAS scores <4). CONCLUSION: The present cross-sectional retrospective study demonstrated the safety of mandibular grafts that reported excellent results in terms of implant success and survival rates with minor complications regarding the donor site area. When the chin was chosen as donor site, minor sensorial disturbances of mucosa and teeth were recorded. The majority of these disturbances were temporary; only few of them were permanent but still had no impact on patient's life.

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.