Vitality of autologous retromolar bone grafts for alveolar ridge augmentation after a 3-months healing period: A prospective histomorphometrical analysis.

OBJECTIVES: The incorporation of retromolar bone grafts used for alveolar ridge augmentation is not well understood. This prospective observational study aims to supply histomorphometrical data from bone graft biopsies taken at the time of retrieval and after a 3-month healing period using patient-matched biopsies. MATERIALS AND METHODS: In 17 patients, trephine biopsies of the graft were acquired at the time of graft retrieval and after a 3-month healing period. The biopsies were compared histomorphometrically regarding the number of osteocytes, appearance of osteocyte lacunae, quantity, surface area, and activity of the Haversian canals. RESULTS: All grafts appeared clinically stable after screw removal and 17 implants were placed. Histomorphometric analysis revealed no significant difference in the number of osteocytes (p = .413), osteocyte lacunae (p = .611), the ratio of filled/empty osteocyte lacunae (p = .467) and active Haversian canals (p = .495) between the biopsies retrieved after a 3-months healing period with those at the time of grafting. The only significant difference was noted in the mean surface area of the Haversian canals (p = .002). Specifically, the grafts post 3-month healing showed a significantly larger mean area (0.069 mm2) compared to the time of grafting (0.029 mm2). CONCLUSION: This study demonstrates, compared to other data, a high rate of vital structures in retromolar bone block grafts after 3 months of healing, exhibiting the same histological features in comparison to the biopsies from the native alveolar ridge. Standard histomorphometrical parameters, e.g., the amount of filled or empty osteocyte lacunae for the description of the vitality of the graft need to be reappraised.

Efficacy of a collagen matrix for soft tissue augmentation after implant placement compared to connective tissue grafts: A multicenter, noninferiority, randomized controlled trial.

OBJECTIVES: To test whether soft tissue volume augmentation using a collagen matrix (VCMX) leads to noninferior results in terms of gain of mucosal thickness at single implant sites, compared to connective tissue grafts (SCTG). METHODS: The study was designed as a multi-center randomized controlled clinical trial. Subjects in need of soft tissue volume augmentation at single tooth implant sites were consecutively recruited at nine centers. The deficient mucosal thickness at the implant sites (one per patient) was augmented by applying either a VCMX or a SCTG. Patients were examined at 120 days (abutment connection = primary endpoint), 180 days (final restoration), and 360 days (1-year after insertion of the final restoration). Outcome measures included: transmucosal probing of the mucosal thickness (crestal = primary outcome), profilometric measurements of the tissue volume, and patient-reported outcome measures (PROMs). RESULTS: Out of the 88 patients, 79 attended the one-year follow-up. The median increase of the crestal mucosal thickness between pre-augmentation and 120 days was 0.3 ± 2.1 mm in the VCMX group and 0.8 ± 1.6 mm in the SCTG group (p = .455). Non-inferiority of the VCMX compared to the SCTG was not observed. The respective numbers at the buccal aspect amounted to 0.9 ± 2.0 mm (VCMX) and 1.1 ± 1.4 mm (SCTG; p = .431). PROMs including pain perception favored the VCMX group. CONCLUSION: It remains inconclusive whether soft tissue augmentation using a VCMX is noninferior to SCTG in terms of crestal mucosal thickening at single implant sites. However, the use of collagen matrices favors PROMs especially pain perception, while achieving similar buccal volume gains along with comparable clinical and aesthetic parameters to SCTG.

Effect of sub-marginal instrumentation before surgical treatment of peri-implantitis: A multi-centre randomized clinical trial.

AIM: The present multi-centre randomized clinical trial with 12 months of follow-up aimed at studying the added effect of sub-marginal instrumentation before surgical treatment of peri-implantitis. MATERIALS AND METHODS: Forty-two patients diagnosed with peri-implantitis were recruited. After a behavioural intervention phase including oral hygiene instructions, patients were randomized to either receiving supra- and sub-marginal instrumentation on their affected implants (control group: 21 patients and 29 implants) or only supra-marginal instrumentation (test group: 21 patients and 24 implants), before undergoing surgery. Changes in the deepest probing pocket depth (PPD) with respect to baseline and a composite outcome of treatment success (no implant loss, no bone loss > 0.5 mm, no bleeding or suppuration on probing [BoP/SoP], and PPD ≤ 5 mm) at the 12-month examination were regarded as the primary outcomes of the trial. RESULTS: At the 12-month examination, changes in the deepest PPD with respect to baseline amounted to -2.96 mm in the control group and to -3.11 mm in the test one (MD = -0.16; SE = 0.56; p = .769), while 21.4% of the implants in the control group and 33.3% in the test group presented treatment success (OR = 1.83; SE = 1.15; p = .338). With the exception of a longer non-surgical treatment duration in the control group (differences in  = -14.29 min; SE = 2.91; p < .001), no other secondary (e.g., soft-tissue recession, keratinized mucosa height, and bone level changes, as well as BoP, SoP, profuse bleeding and implant loss rates) or exploratory (i.e., early wound healing, aesthetics, surgical and total treatment duration, surgery difficulty, intra-operative bleeding, and adverse events) outcome demonstrated statistically significant differences between groups. CONCLUSIONS: The present multi-centre randomized clinical trial did not demonstrate an added effect of performing sub-marginal instrumentation 6 weeks before the surgical treatment of peri-implantitis. Larger clinical trials are however needed to confirm the present findings (Clinicaltrials.gov: NCT03620331).

Comparison of a polyethylene glycol membrane and a collagen membrane for the treatment of bone dehiscence defects at bone level implants-A prospective, randomized, controlled, multicenter clinical trial.

OBJECTIVES: The aim of the present randomized, controlled clinical multicenter trial was to compare a polyethylene glycol (PEG) and a native collagen membrane (BG) for simultaneous guided bone regeneration at bony dehiscence-type defects around bone level titanium implants. MATERIAL AND METHODS: The study enrolled 117 patients requiring implant treatment in the posterior maxilla or mandible with expected buccal bony dehiscence-type defects at the placed titanium implants. According to a parallel groups design, defects were filled with a synthetic bone filler and randomly assigned to either PEG or BG membrane. As primary parameter, the relative vertical bone fill was assessed at baseline and at re-entry after 6 months of healing. As secondary parameters, the marginal bone level (MBL) was assessed radiographically and soft tissue conditions were recorded up to 18 months postloading. RESULTS: Both groups showed comparable vertical bone fill revealing a relative change in defect height of 59.7% (PEG) and 64.4% (BG). The absolute mean reduction in defect size was 2.5 mm in the PEG group and 3.2 mm in the BG group. Although both groups revealed a statistically significant mean defect reduction (p < .001), a comparison between the two groups did not show statistical significances. The non-inferiority test with inferiority limit of -5% could not be rejected, based on the 90% confidence interval of the differences of the two means with lower limit -15.4%. After 18 months, an MBL increase of 0.45 ± 0.43 mm in the PEG group and 0.41 ± 0.81 mm in the BG group was detected (p < .001). Soft tissue complications were observed in both groups without showing statistical significance. CONCLUSIONS: Both membranes supported bone regeneration at dehiscence-type defects and obtained vertical bone fill with a relative change in defect height of 59.7% (PEG) and 64.4% (BG); however, the non-inferiority of PEG could not be shown.

Regeneration of alveolar ridge defects. Consensus report of group 4 of the 15th European Workshop on Periodontology on Bone Regeneration.

BACKGROUND AND AIMS: Bone augmentation procedures to enable dental implant placement are frequently performed. The remit of this working group was to evaluate the current evidence on the efficacy of regenerative measures for the reconstruction of alveolar ridge defects. MATERIAL AND METHODS: The discussions were based on four systematic reviews focusing on lateral bone augmentation with implant placement at a later stage, vertical bone augmentation, reconstructive treatment of peri-implantitis associated defects, and long-term results of lateral window sinus augmentation procedures. RESULTS: A substantial body of evidence supports lateral bone augmentation prior to implant placement as a predictable procedure in order to gain sufficient ridge width for implant placement. Also, vertical ridge augmentation procedures were in many studies shown to be effective in treating deficient alveolar ridges to allow for dental implant placement. However, for both procedures the rate of associated complications was high. The adjunctive benefit of reconstructive measures for the treatment of peri-implantitis-related bone defects has only been assessed in a few RCTs. Meta-analyses demonstrated a benefit with regard to radiographic bone gain but not for clinical outcomes. Lateral window sinus floor augmentation was shown to be a reliable procedure in the long term for the partially and fully edentulous maxilla. CONCLUSIONS: The evaluated bone augmentation procedures were proven to be effective for the reconstruction of alveolar ridge defects. However, some procedures are demanding and bear a higher risk for post-operative complications.

European Association for Osseointegration Delphi study on the trends in Implant Dentistry in Europe for the year 2030.

OBJECTIVES: To assess the potential trends for the year 2030 in dental implant dentistry in Europe using the Delphi methodology. MATERIAL AND METHODS: A steering committee and a management team of experts in implant dentistry were created and validated a questionnaire including 60 questions, divided in eight topics. The survey was conducted in two rounds using an anonymous questionnaire, which provided the participants in the second round with the results of the first. Each question had three possible answers, and the results were expressed as percentages. RESULTS: A total of 138 experts were invited to participate in the survey. From all the invited experts, 52 answered in both the first and second rounds. Three different consensus categories were established based on the percentage of agreement: no consensus (<65%); moderate consensus (65%-85%); and high consensus (≥86%). Within the topic categories, a consensus was reached (mainly moderate consensus) for the majority of questions discussed among experts during a face to face consensus meeting. However, consensus was not reached for a small number of questions/topics. CONCLUSIONS: About 82% of the questions reached consensus. The consensus points towards a lower number of implants to replace chewing units, with implants surfaces made of bioactive materials with reduced micro-roughness using mainly customized abutments with polished surfaces and an internal implant-abutment connection (85%). CBCT-3D technologies will be the main tool for pre-surgical implant placement diagnosis together with direct digital restorative workflows. There will be an increase in the incidence of peri-implantitis, although there will be more efficient interventions its treatment and prevention.

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.

Group 3 ITI Consensus Report: Patient-reported outcome measures associated with implant dentistry.

OBJECTIVES: The aim of Working Group 3 was to focus on three topics that were assessed using patient-reported outcome measures (PROMs). These topics included the following: (a) the aesthetics of tooth and implant-supported fixed dental prostheses focusing on partially edentulous patients, (b) a comparison of fixed and removable implant-retained prostheses for edentulous populations, and (c) immediate versus early/conventional loading of immediately placed implants in partially edentate patients. PROMs include ratings of satisfaction and oral health-related quality of life (QHRQoL), as well as other indicators, that is, pain, general health-related quality of life (e.g., SF-36). MATERIALS AND METHODS: The Consensus Conference Group 3 participants discussed the findings of the three systematic review manuscripts. Following comprehensive discussions, participants developed consensus statements and recommendations that were then discussed in larger plenary sessions. Following this, any necessary modifications were made and approved. RESULTS: Patients were very satisfied with the aesthetics of implant-supported fixed dental prostheses and the surrounding mucosa. Implant neck design, restorative material, or use of a provisional restoration did not influence patients' ratings. Edentulous patients highly rate both removable and fixed implant-supported prostheses. However, they rate their ability to maintain their oral hygiene significantly higher with the removable prosthesis. Both immediate provisionalization and conventional loading receive positive patient-reported outcomes. CONCLUSIONS: Patient-reported outcome measures should be gathered in every clinical study in which the outcomes of oral rehabilitation with dental implants are investigated. PROMs, such as patients' satisfaction and QHRQoL, should supplement other clinical parameters in our clinical definition of success.

Accuracy comparison of guided surgery for dental implants according to the tissue of support: a systematic review and meta-analysis.

AIM: To systematically assess the current dental literature comparing the accuracy of computer-aided implant surgery when using different supporting tissues (tooth, mucosa, or bone). MATERIAL AND METHODS: Two reviewers searched PubMed (1972 to January 2015) and the Cochrane Central Register of Controlled Trials (Central) (2002 to January 2015). For the assessment of accuracy, studies were included with the following outcome measures: (i) angle deviation, (ii) deviation at the entry point, and (iii) deviation at the apex. RESULTS: Eight clinical studies from the 1602 articles initially identified met the inclusion criteria for the qualitative analysis. Four studies (n = 599 implants) were evaluated using meta-analysis. The bone-supported guides showed a statistically significant greater deviation in angle (P < 0.001), entry point (P = 0.01), and the apex (P = 0.001) when compared to the tooth-supported guides. Conversely, when only retrospective studies were analyzed, not significant differences are revealed in the deviation of the entry point and apex. The mucosa-supported guides indicated a statistically significant greater reduction in angle deviation (P = 0.02), deviation at the entry point (P = 0.002), and deviation at the apex (P = 0.04) when compared to the bone-supported guides. Between the mucosa- and tooth-supported guides, there were no statistically significant differences for any of the outcome measures. CONCLUSIONS: It can be concluded that the tissue of the guide support influences the accuracy of computer-aided implant surgery.

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 failure and clinical and radiographic outcomes after surgical treatment of peri-implantitis: A meta-analysis.

PURPOSE: To assess the implant failure rate and clinical and radiographic outcomes of implants affected by peri-implantitis that received surgical treatment. MATERIALS AND METHODS: A systematic search was conducted of three databases (PubMed, Embase and Cochrane Library) to identify studies that examined implant failure and biological outcomes after surgical peri-implantitis treatment, including ≥ 10 patients and reporting on a follow-up period of at least 12 months. Data and risk of bias were assessed qualitatively and quantitively. Surgical modalities were subdivided into reconstructive, non-reconstructive and combined. Meta-analyses were performed for implant failure, marginal bone level and probing pocket depth at 12 and 36 months with the respective subset of available data for each time and endpoint. RESULTS: A total of 45 studies with 3,463 treated implants were included in the quantitative evaluation. Meta-analyses revealed low implant failure rates of 1.2% (95% confidence interval 0.4%, -2.1%) and 4.2% (95% confidence interval 1.0%, -8.8%) at 12 and 36 months, respectively. No significant difference between the subgroups was observed at 12 months. At 36 months, reconstructive modalities showed a significantly lower implant failure rate (1.0%; 95% confidence interval 0.0%, 5.0%; P = 0.04, χ2(1) = 4.1) compared to non-reconstructive modalities (8.0%; 95% confidence interval 2.0%, 18.0%). The mean probing pocket depth was 3.71 mm (95% confidence interval 3.48, 3.94 mm) at 12 months and 3.63 mm (95% confidence interval 3.02, 4.24 mm) at 36 months. The mean marginal bone loss was 3.31 mm (95% confidence interval 2.89, 3.74 mm) at 12 months and 2.38 mm (95% confidence interval 1.01, 3.74 mm) at 36 months. No significant differences between the modalities were observed for bleeding on probing after either of these time points. Cumulative interventions during supportive therapy were reported in 9% of the studies. CONCLUSION: Surgical treatment of peri-implantitis results in a low implant failure rate in the short and medium term. No differences were noted between the different interventions with regard to failure rate. Surrogate therapeutic endpoints were improved after treatment, without significant differences between the different modalities. Therapeutic success and/or disease resolution and cumulative interventions during supportive therapy are seldom reported in the literature, but limited long-term outcomes are documented consistently.

Indications for implant-supported rehabilitation of the posterior atrophic maxilla: A multidisciplinary consensus among experts in the field utilising the modified Delphi method.

PURPOSE: To establish consensus-driven guidelines that could support the clinical decision-making process for implant-supported rehabilitation of the posterior atrophic maxilla and ultimately improve long-term treatment outcomes and patient satisfaction. MATERIALS AND METHODS: A total of 33 participants were enrolled (18 active members of the Italian Academy of Osseointegration and 15 international experts). Based on the available evidence, the development group discussed and proposed an initial list of 20 statements, which were later evalu-ated by all participants. After the forms were completed, the responses were sent for blinded ana-lysis. In most cases, when a consensus was not reached, the statements were rephrased and sent to the participants for another round of evaluation. Three rounds were planned. RESULTS: After the first round of voting, participants came close to reaching a consensus on six statements, but no consensus was achieved for the other fourteen. Following this, nineteen statements were rephrased and sent to participants again for the second round of voting, after which a consensus was reached for six statements and almost reached for three statements, but no consensus was achieved for the other ten. All 13 statements upon which no consensus was reached were rephrased and included in the third round. After this round, a consensus was achieved for an additional nine statements and almost achieved for three statements, but no consensus was reached for the remaining statement. CONCLUSION: This Delphi consensus highlights the importance of accurate preoperative planning, taking into consideration the maxillomandibular relationship to meet the functional and aesthetic requirements of the final restoration. Emphasis is placed on the role played by the sinus bony walls and floor in providing essential elements for bone formation, and on evaluation of bucco-palatal sinus width for choosing between lateral and transcrestal sinus floor elevation. Tilted and trans-sinus implants are considered viable options, whereas caution is advised when placing pterygoid implants. Zygomatic implants are seen as a potential option in specific cases, such as for completely edentulous elderly or oncological patients, for whom conventional alternatives are unsuitable.

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.

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.

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.

Involvement of the Notch signaling system in alveolar bone resorption.

The Notch pathway is an evolutionarily preserved signaling pathway involved in a variety of vital cell functions. Additionally, it is one of the key regulators of inflammation, and controls the differentiation and function of different cells. Moreover, it was found to be involved in skeletal development and bone remodeling process. This review provides an overview of the involvement of the Notch signaling pathway in the pathogenesis of alveolar bone resorption in different forms of pathological conditions such as apical periodontitis, periodontal disease, and peri-implantitis. In vitro and in vivo evidence have confirmed the involvement of Notch signaling in alveolar bone homeostasis. Nonetheless, Notch signaling system, along with complex network of different biomolecules are involved in pathological process of bone resorption in apical periodontitis, periodontitis, and peri-implantitis. In this regard, there is a substantial interest to control the activity of this pathway in the treatment of disorders associated with its dysregulation. This review provides knowledge on Notch signaling and outlines its functions in alveolar bone homeostasis and alveolar bone resorption. Further investigations are needed to determine whether inhibition of the Notch signaling pathways might be beneficial and safe as a novel approach in the treatment of these pathological conditions.

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.

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.

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.