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This retrospective study evaluates the clinical and radiographic outcomes of simultaneous guided bone regeneration (GBR) and implant placement procedures in the rehabilitation of partially edentulous and horizontally atrophic dental arches using resorbable membranes. A total of 49 patients were included, and 97 implants were placed. Patients were followed up for 3 to 7 years after loading. The data indicate that GBR with simultaneous implant placement and resorbable membranes can be a good clinical choice, and the data suggest that it could be better to horizontally reconstruct no more than 3 mm of bone in order to reduce the number of complications and to obtain stable results. However, this technique remains difficult and requires expert surgeons.

The aim of the present study was to generate an international and multidisciplinary consensus on the clinical management of implant protrusion into the maxillary sinuses and nasal fossae. A total of 31 experts participated, 23 of whom were experts in implantology (periodontologists, maxillofacial surgeons and implantologists), 6 were otolaryngologists and 2 were radiologists. All the participants were informed of the current scientific knowledge on the topic based on a systematic search of the literature. A list of statements was created and divided into three surveys: one for all participants, one for implant providers and radiologists and one for otolaryngologists and radiologists. A consensus was reached on 15 out of 17 statements. According to the participants, osseointegrated implants protruding radiographically into the maxillary sinus or nasal fossae require as much monitoring and maintenance as implants fully covered by bone. In the event of symptoms of sinusitis, collaboration between implant providers and otolaryngologists is required. Implant removal should be considered only after pharmacological and surgical management of sinusitis have failed.

Objectives To compare the 1-year aesthetic results of flapless single implants, placed in fresh extraction sockets with bone replacement and immediate provisional restoration with or without a connective tissue graft (CTG). Material and methods The present study proposes a partially blinded multicentre parallel randomized controlled trial, where computer-generated tables were used for central randomization to allocate treatments. A total of 59 of the 60 patients screened by eight private practices in Northern Italy fulfilled the inclusion criteria. Immediate implants were placed in a fresh extraction socket with a non-functional immediate provisional restoration with (Test group) or without (Control group) a CTG. The primary outcome variable was the implant Crown Aesthetic Index (ICAI) at the 1-year follow-up. Results ICAI for the 59 randomized patients (Test group = 31, Control group = 28) at the 1-year follow-up was 4.69 (95% CI = 3.16-6.22) for the Test group and 3.45 (95% CI = 1.83-5.08) for the Control group, without statistically significant difference between the two groups (p = .086). One implant failure was recorded in each group, resulting in an implant survival rate of 96.8% [95% CI = 83.3-99.9] for the Test group and 96.4% [95% CI = 81.7-99.9] for the Control group. Other secondary outcome variables and complication rates were comparable across the two groups. Conclusions Within the limitations of the present clinical trial, the results suggested that the adjunct use of CTG is not mandatory to achieve successful aesthetic outcomes for a well-planned immediate implant placement with immediate non-functional provisional restoration in a fresh extraction socket.

The aim of the present split-mouth prospective study was to evaluate clinically and histologically the bone regeneration obtained following preprosthetic vertical bone augmentation performed with titanium-reinforced dense polytetrafluoroethylene membrane (d-PM) compared to titanium mesh (TM).Healthy adult patients presenting with bilateral partial edentulism in the posterior mandible requiring vertical ridge augmentation for implant placement purposes were consecutively included. One side of the mandible was randomly assigned to the use of d-PM, the other to TM. The graft consisted in a mixture of autogenous bone harvested nearby the surgical site and deproteinized bovine bone mineral particles in a 1:1 ratio. On each side during bone augmentation surgery, a 2-mm diameter mini-implant was inserted for clinical and histological analyses. After a healing period of 8 months, the second surgical phase was carried out to remove the nonresorbable barriers, to evaluate clinically the vertical bone gain, and to collect a bone biopsy that included the mini-implant. During the same surgical session, dental implants were inserted in a prosthetically guided position.A total of five patients were enrolled. Eight out of 10 sites healed uneventfully. In the remaining two sites, premature exposure of the TM was observed. Mean vertical bone gain of 4.2 and 1.5 mm was achieved in d-PM and TM groups, respectively (The vertical bone gain, although not significantly, was higher in the d-PM group. Similar histological outcomes were noticed if exposure did not occur. In case of wound dehiscence, major resorption was observed.Both d-PM and TM can be used to augment atrophic localized ridges vertically. The outcome of bone regeneration seems to be impaired by exposure of the device. How to cite this article: Maiorana C, Fontana F, Rasia dal Polo M

In everyday practice, surgeons have to deal with bone atrophy. These rehabilitations are even more complex in the posterior mandible, and it is still unclear in the literature which fixed rehabilitation option is best. The purpose of this article was to help oral surgeons to choose the proper and updated treatment for their atrophic patients. Posterior mandible bone atrophies were divided into four main groups depending on the bone height measured above the inferior alveolar nerve: (1) ≤ 4 mm; (2) > 4 mm ≤ 5 mm; (3) > 5 mm ≤ 6 mm; (4) > 6 mm < 7 mm. Different approaches were proposed for each group, considering patient expectations. If ≤ 4 mm of bone height was available, guided bone regeneration was used as the adequate approach. For bone heights > 4 mm and ≤ 6 mm, the "sandwich" technique and/or short implants were used, depending on esthetics. In cases with > 6 mm and < 7 mm above the mandibular canal, short implants might be the proper option. The authors' clinical experience and the literature were considered in order to suggest a possible correct treatment decision based on the residual bone height in the posterior mandible.

This prospective longitudinal clinical trial aimed to evaluate the success of a bone-level implant with an integrated platform-switched connection by assessing peri-implant soft tissue and marginal bone level. Twenty-six patients were treated in two different centers with implants placed in healed partially edentulous ridges. Implant success rate and marginal bone level were evaluated with photographs, radiographs, and clinical measurements, with a 6-month postloading follow-up. The esthetic appearance of the photographed peri-implant soft tissue was evaluated at 6 months via the Pink Esthetic Score applied by two calibrated operators. All of the implants except for one placed in the mandible demonstrated successful osseointegration, resulting in a success rate of 97.8% at the 6-month follow-up. Compared to historical controls, no detectable differences in peri-implant marginal bone loss or esthetic outcome were seen.

The goal of this retrospective investigation was to provide evidence of the longevity of machine-surfaced implants placed in native bone and treated with the original two-stage surgical protocol. The observation times of this study covered periods of 13 to 32 years. Consecutive cases were impossible; the patients' ages when treated reduced the number of available people as a result of death, relocation, being impossible to find, or refusal to cooperate. Mean marginal bone loss after 13 to 32 years was 1.9 ± 0.9 mm, survival rate was 97.7%, and success rate was 92.7%. Peri-implantitis occurred in a limited number of cases, with a prevalence of 1.8%. This study demonstrates long-term reliability of machined implants as a therapeutic choice.

The reconstruction of deficient alveolar ridges using vertical and/or horizontal guided bone regeneration techniques allows for ideal implant placement, which is crucial for function and also for esthetically successful outcomes. Unlike in the past, when meeting a patient's functional demands was sufficient, many patients now have greater expectations from their implant restoration. Hence, it is no longer enough simply to restore the edentulous space with a functioning tooth or teeth. It has been suggested that patients now measure their final restoration using the contralateral natural tooth as the gold standard. Both subjective and objective levels of patient information on dental implants have increased significantly in the last decade. As a result of this demand, implant literature has inherited and developed specific esthetic parameters and patient-centered outcomes from studies in the restorative field. Unfortunately, studies reporting on guided bone regeneration in the esthetic zone entirely lack such parameters and outcomes. Currently, there is a strong need for a consensus on objective and well-defined parameters to assess the esthetics in bone regeneration and subsequently on implant dentistry.

The aim of this retrospective study was to evaluate clinical and radiographic outcomes of guided bone regeneration (GBR) procedures in the rehabilitation of partially edentulous atrophic arches. A total of 58 patients were included with a follow-up of 3 to 7 years after loading. Data seem to indicate that GBR with nonresorbable membranes can be a good clinical choice and suggest that it could be used to vertically reconstruct no more than 6 mm of bone in the posterior mandible. However, this technique remains difficult and requires expert surgeons.

The aim of this study is to evaluate the long-term performance of anodized surface implants placed in native bone and followed-up for up to 17 years. Success and survival rates, prevalence of peri-implantitis, and the correlation between the presence of peri-implantitis and other clinical and demographic variables were calculated. After a mean follow-up time of 10.4 years (range: 5 to 17 years), 91.7% of 223 analyzed implants were still in function. Peri-implantitis affected 63 implants (28.3%) in 26 patients (44%). Eleven implants with peri-implantitis (4.9%) failed. Within the limits of this retrospective analysis, anodized implants appear to be prone to peri-implantitis, mainly in the posterior mandible and in patients with unsatisfactory plaque control.

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 postoperative complications. This article is protected by copyright. All rights reserved.

This case report provided a unique opportunity to investigate the extent of microbiota infiltration on the oxidized implant surface that has been compromised by peri-implantitis. Scanning electron microscopic analysis confirmed the etiologic role of the bacteria on the loss of supporting structure and the difficulty in complete removal of bacterial infiltration on the implant surface. This case report emphasizes the need to perform definitive surface decontamination on failing dental implants prior to a regeneration procedure.

This case report presents the correction of severe alveolar ridge atrophy due to congenital and iatrogenic factors. Implants that compromised the natural adjacent teeth and overall esthetics for this young patient were removed and replaced after significant vertical bone and soft tissue regenerative procedures. A treatment combination of bone graft particles, a nonresorbable membrane, and enamel matrix derivatives was used. Significant and stable improvement in esthetics was achieved 12 months after final prosthetic restoration, demonstrating the ability of such a combined treatment to correct the esthetic deformity, improve the health of the adjacent natural teeth, and allow for successful implant treatment.

L’obiettivo di questo studio retrospettivo è quello di comparare i risultati clinici e radiografici della tecnica di aumento osseo interposizionale (inlay), in mandibole posteriori atrofiche parzialmente edentule, utilizzando tre diversi tipi di innesti ossei a blocco: blocchi di osso autologo prelevati dalla cresta iliaca, blocchi di osso bovino deproteinizzato e blocchi di osso equino collagenato. Sono stati inclusi in totale 115 pazienti con un follow-up medio dopo il carico protesico di 4,2 anni. I dati sembrano indicare come i blocchi di osso eterologo siano similari, per quanto riguarda i risultati, ai blocchi di osso autologo; tali blocchi per cui dovrebbero essere ritenuti preferibili in quanto consentono di evitare chirurgie invasive di prelievo osseo.

Background Vertical ridge augmentation with the use of solid bone blocks or particulate bone autograft, exposed or covered by a nonresorbable expanded polytetrafluoroethylene (ePTFE) membrane, are well known in the literature and have been shown to be effective in treating bone atrophy. Purpose The aim of our study was to assess the two techniques in respect to biological properties of transplanted bone in graft revascularization and bone remodeling in conjunction with dental implants. Materials and Methods Ten patients were treated within the study, with a total of 12 sites with posterior mandibular edentulous ridges with insufficient bone to allow implant placement. Bone regeneration was performed using autogenous intraoral block graft or autogenous particulate graft with an ePTFE barrier membrane. At 6–10 months, reentry surgery was performed; bone biopsies, including microscrews, were harvested; and implants were placed. Results Eleven sites out of 12 healed uneventfully. A mean height gain of 5.03 mm was achieved. Mean bone-to-implant contact and bone fill were assessed by means of histomorphometric analysis. The block specimens revealed a bone-to-implant contact of 42.34%, and the particulate grafts had a bone-to-implant contact of 26.62% (p

Various designs of dental implants representing different geometries and surface technologies are commercially available for patient treatment. However, data with regard to the biologic events that occur immediately after implant placement, regardless of the surface characteristic, are scarce. It has become a common procedure to perform immediate/early prosthetic loading rather than delayed loading. The goal of this study was to observe the early biologic events of peri-implant healing to understand the role of surface modifications in relation to the early phases of bone integration. The secondary goal was to observe the possible differences in the healing pattern at two oral implant surfaces differing in morphology and roughness (Ra, with Ra values ranging from 0.5 μm (machined surface; MS) to 1.5 μm (oxidized surface; OS). A total of 36 implants were placed in six foxhound dogs, equally divided between machined and oxidized surfaces. Three implants were positioned per hemimandible following a randomization scheme. Each animal was euthanized at a specific time point for histologic observation and histomorphometry: immediately after implant insertion and after 24 hours, 7 days, 15 days, 30 days, and 90 days. The study demonstrated an extremely low bone-implant contact (BIC) for both OS and MS implant surfaces during the first 15 days after implant placement (ranging from 12.9% to 26.9% independent of the implant surface). Increased BIC values were observed only in the 30- and 90-day specimens. The presence and the degradation of residual bone particles acted as centers for new bone formation, with osteoblasts lining osteoid tissue and subsequently woven bone independent of the implant surface characteristics. The bone-forming activity appeared strongly reduced after 30 days of healing and seemed to be complete only in the 90-day specimens, where abundant lamellar bone was evident. There is a continuing effort to develop improved titanium surfaces to achieve more rapid osseointegration and improve BIC, with the ultimate goal of applying occlusal load as early as possible. Since immediate or early implant loading is applied during and not after the first 15 days, the findings in the present study of an extremely low BIC and limited mineralized bone formation for both implant surfaces during the first 15 days after implant placement suggest that the surface roughness may not be a key factor for successful osseointegration of immediately or early loaded implants. Within the limits of this study, it can be stated that osseointegration follows a similar healing pattern with machined and oxidized implant surfaces.

Purpose To retrospectively evaluate the survival rate of machined implants in sinus-lifted posterior maxilla after 12 years, with special reference to radiographic outcome and peri-implantitis. Materials and Methods From 37 possible candidates, 29 patients with 59 implants were evaluated. Implants were placed in the posterior maxilla in combination with a sinus elevation procedure (27 patients) or 6 months after sinus elevation (2 patients). Marginal bone level changes were radiographically evaluated at baseline and 1, 7, and 12 years post-loading. Probing depth was measured; presence/absence of plaque and bleeding on probing were recorded. Results Four out of 59 implants failed in 4 out of 29 patients (cumulative survival rate = 93.2%). The mean bone loss was 0.78 mm (± 0.88) after 12 years. Changes in the mean bone level were statistically significant between baseline and all the other follow-up intervals (p

A short inflammatory phase and fast ingrowth of blood vessels and mesenchymal cells are essential for tissue integration of a biomaterial. Macrophages play a key role in this process. We investigated invasion of macrophages, blood vessels, and proliferating cells into a highly porous and volume-stable collagen matrix (VCMX) used for soft tissue augmentation around teeth and dental implants. The biomaterial was implanted in submucosal pouches in the canine maxilla, and the tissue response was analyzed at six different time points. Immunohistochemistry was done for proliferating cells (PCNA), macrophages (MAC387), multinucleated giant cells (CD86), and blood vessels (TGM2). Blood rapidly filled the VCMX pores. During the first week, MAC387+ cells populated the VCMX pores, blood vessels and PCNA+ cells invaded the VCMX, and CD86+ scattered cells were observed. At 15 days, MAC387+ cells were scanty, blood vessels had completely invaded the VCMX, the number of proliferating cells peaked, and fibroblasts appeared. At 30 days, MAC387+ were absent, the numbers of proliferating and CD86+ cells had declined, while blood vessel and fibroblast numbers were high. At 90 days, residual VCMX was well-integrated in soft connective tissue. In conclusion, the VCMX elicited a short inflammatory phase followed by rapid tissue integration.

PURPOSE: This article describes the digitoclastic technique, an innovative procedure for coronal displacement of the lingual flap. The new technique has the potential to obtain primary flap closure without surgical risks to the anatomical structures on the lingual side of the mandible. MATERIALS AND METHODS: Reconstruction of an atrophic mandible with guided tissue regeneration (guided bone regeneration) and implant placement is described, using the digitoclastic technique to displace the lingual flap coronally. RESULTS: Coronal flap displacement was sufficient to obtain complete passive coverage of the grafted area. No bleeding or neurosensory complications were recorded, and no membrane exposure occurred. CONCLUSIONS: The digitoclastic technique reduces the risk of damage to the lingual nerve and minimizes the amount of bleeding during surgery, allowing progressive and controlled retraction of the flap until the desired detachment is achieved.

Reducing the need for a connective tissue graft by using an efficacious biomaterial is an important task for dental professionals and patients. This experimental study aimed to test the soft tissue response to a volume-stable new collagen matrix. The device demonstrated good stability during six different time points ranging from 0 to 90 days of healing with no alteration of the wound-healing processes. The 90-day histologic specimen demonstrates eventual replacement of most of the matrix with new connective tissue fibers.

The aim of this retrospective clinical trial was to evaluate the performance of 91 turned implants placed in vertically augmented ridges in 33 patients by means of guided bone regeneration techniques after a mean follow-up of 15 years. A total of 88 implants were in function (97% survival rate), whereas 9 showed peri-implantitis (9.9%). A mean radiographic bone loss of 1.02 mm between the baseline evaluation (1 year after loading) and the final visit (13 to 21 years later) was recorded. In conclusion, turned implants placed in vertically augmented bone seem to remain stable after many years of function.

Riassunto Obiettivi. Guidare il chirurgo nella scelta se effettuare o no un impianto post-estrattivo e su come gestire le diverse situazioni cliniche che si verificano in corso di terapia. Materiali e metodi. Valutare i principi alla base dell’osteointegrazione, confrontando i moderni orientamenti con i protocolli originali e analizzare i processi biologici della guarigione di un alveolo post-estrattivo. Porre in evidenza, nel modo piu schematico possibile, indicazioni e limiti di questa tecnica e descriverne i dettagli chirurgici. I pazienti oggetto dei casi clinici descritti nel presente articolo hanno concesso il loro consenso informato alle terapie e alla pubblicazione di materiale relativo alle cure loro prestate. Risultati e conclusioni. Gli impianti post-estrattivi rappresentano un’alternativa terapeutica che, valutando attentamente il singolo caso clinico, puo agevolare operatore e paziente sotto diversi aspetti. Le percentuali di successo implantare sono sovrapponibili a quelle degli impianti in osso nativo; i tempi di lavoro, la durata delle sedute chirurgiche e i fastidi per il paziente risultano decisamente inferiori. Si tratta tuttavia di una procedura tecnicamente piu complessa e per quanto riguarda i risultati estetici si deve valutare attentamente ogni singolo caso in relazione a diversi parametri individuali.

Objectives: The aim of the present study was to evaluate a Ca–P coated implant surface in a rabbit model. The Ca–P surface (test) was compared to the titanium porous oxide surface (control) in terms of bone-to-implant contact (BIC) and removal torque value. Materials and methods: Two hundred and sixteen dental implants were inserted in the tibia and in the femur of 36 rabbits. One hundred and eight were represented by Ca–P oxidized surface implant and other 108 were titanium porous oxide surface modified implants. Each rabbit received six implants. Animals were sacrificed after 2, 4 and 9 weeks of healing. Each group included 12 rabbits. The femoral implant and the proximal implant of the tibia of each animal were subjected to the histologic analysis and the distal implants of the tibia underwent removal torque test (RTQ). Results: Histological analysis in terms of BIC and RTQ did not revealed any significant difference between the Ca–P oxidized surface and the oxidized surface at 2 and 4 weeks. At 9 weeks, the oxidized surface demonstrated better results in terms of RTQ in the tibia. Conclusion: In conclusion, findings from the present study suggested that the Ca–P coating had no beneficial effect in improving bonding strength at the bone–implant interface either at 2, 4 and 9 weeks. In the last few years, a number of surface modifications have been proposed to increase the bone-to-implant contact (BIC) and to accelerate bone deposition at the implant surface.

Purpose: In the present prospective study, bone augmentation by guided bone regeneration (GBR) in combination with bovine hydroxyapatite (BHA) as filling material was evaluated with regard to soft and hard tissue stability over time. Materials and Methods: Implant survival, radiologic bone level (marginal bone level [MBL]), and clinical soft tissue parameters (marginal soft tissue level [MSTL]) were observed. Twenty patients received a total of 41 implants (Branemark System, Nobel Biocare, Goteborg, Sweden) in conjunction with GBR treatment. The end point of the study was after 5 years following implant placement. Results: The cumulative implant survival rate was 97.5% corresponding to one implant failure. The radiologic evaluation of the MBL demonstrated a crestal bone height above the level of the fixture head. The bone height decreased from −3.51 to −2.38 mm (p

Introduction: Several surgical techniques and prosthetic devices have been developed in the last decades, aiming to improve aesthetic, hygienic and functional outcomes that may affect the peri-implant tissues, such as procedures of bone and soft tissue augmentation and the use of custom-made abutments of titanium and zirconium.Materials and methods: Three systematic reviews, based on randomized clinical trials and prospective studies covering the above reported topics were analysed, and the detected evidence was exposed to interactive experts' discussion during the group's and general assembly's meetings of the 4th EAO Consensus Conference. The results are reported using the following abbreviations: ST: short-term evidence, M-T: medium-term evidence; L-T: long-term evidence; LE: limited evidence.Results: Soft tissue augmentation procedures may be indicated for the increase of soft tissue thickness and keratinized tissue, the reduction of interproximal peri-implant bone loss, and the coverage of shallow peri-implant soft tissue recessions (S-T, LE), L-T is lacking. Guided bone regeneration approaches (GBR) showed efficacy when used for ridge reconstruction after the complete healing of the soft tissues (S-T & L-T), and the stability of the augmented bone may play a role in the maintenance of the soft tissue position and dimensions (LE). No significant differences were observed between titanium and zirconia abutments when evaluating probing pocket depth, bleeding on probing, marginal bone levels and mucosal recessions. Zirconia abutments were associated with more biological complications but demonstrated superiority in terms of achieving natural soft tissue colour (S-T).

Background Peri-implant hard-tissue augmentation is a widely used clinical procedure. Aim The present review aimed to analyse the current literature regarding medium- and long-term data concerning the stability of peri-implant tissues after hard-tissue augmentation prior or immediately with implant placement. Material and methods An electronic literature search was performed using Medline (PubMed) databases detecting clinical studies focusing on hard- and soft-tissue stability around dental implants placed either in augmented alveolar ridges or simultaneously with peri-implant bone grafting. The search was limited to articles published between 1995 and December 2014, focusing on clinical studies with a prospective study design assessing peri-implant bone and soft tissue stability over time with a minimum follow-up of 12 months. Recent publications were also searched manually to find any relevant studies that might have been missed using the search criteria noted above. Results Thirty-seven articles met the inclusion criteria and were included in this systematic review. Since the outcome measures and methods, as well as types of grafts and implants used were so heterogeneous, the performance of meta-analysis was impossible. The highest level of evidence was achieved by randomized clinical trials. Conclusion Different hard-tissue augmentation procedures seem to show stable peri-implant tissues, although, up to now, long-term stability of the augmented buccal bone is assessed by only few studies. Further research should concentrate on combining three-dimensional radiographic data with non-invasive methods as digital surface measuring techniques or ultrasound evaluation.

Vertical ridge augmentation with the use of solid bone blocks or particulate bone autograft, exposed or covered by a nonresorbable expanded polytetrafluoroethylene (ePTFE) membrane, are well known in the literature and have been shown to be effective in treating bone atrophy.The aim of our study was to assess the two techniques in respect to biological properties of transplanted bone in graft revascularization and bone remodeling in conjunction with dental implants.Ten patients were treated within the study, with a total of 12 sites with posterior mandibular edentulous ridges with insufficient bone to allow implant placement. Bone regeneration was performed using autogenous intraoral block graft or autogenous particulate graft with an ePTFE barrier membrane. At 6-10 months, reentry surgery was performed; bone biopsies, including microscrews, were harvested; and implants were placed.Eleven sites out of 12 healed uneventfully. A mean height gain of 5.03 mm was achieved. Mean bone-to-implant contact and bone fill were assessed by means of histomorphometric analysis. The block specimens revealed a bone-to-implant contact of 42.34%, and the particulate grafts had a bone-to-implant contact of 26.62% (p .012). Bone fill values reported were 68.32% and 48.28% (p .019) for block specimens versus particulate grafts.The results clearly showed that both techniques were clinically successful for subsequent implant placement and prosthetic rehabilitation. The histological outcomes, including revascularization and bone remodeling, of the two techniques differed significantly. The block grafts outperformed the particulate grafts in terms of bone-to-implant contact and bone fill values; however, the morbidity associated with the donor site of the block must be considered.

Objectives The fresh extraction socket in the alveolar ridge represents a special challenge in everyday clinical practice. Maintenance of the hard and soft tissue envelope and a stable ridge volume were considered important aims to allow simplifying subsequent treatments and optimizing their outcomes in particular, when implants are planned to be placed. Material and Methods: Prior to the consensus meeting four comprehensive systematic reviews were written on two topics regarding ridge alteration and ridge preservation following tooth extraction and implant placement following tooth extraction. During the conference these manuscripts were discussed and accepted thereafter. Finally, consensus statements and recommendations were formulated. Results: The systematic reviews demonstrated that the alveolar ridge undergoes a mean horizontal reduction in width of 3.8 mm and a mean vertical reduction in height of 1.24 mm within 6 months after tooth extraction. The techniques aimed at ridge preservation encompassed two different approaches: i) maintaining the ridge profile, ii) enlarging the ridge profile. Regarding timing of implant placement the literature showed that immediate implant placement leads to high implant survival rates. This procedure is primarily recommended in premolar sites with low esthetic importance and favorable anatomy. In the esthetic zone, however, a high risk for mucosal recession was reported. Hence, it should only be used in stringently selected situations with lower risks and only by experienced clinicians. In molar sites a high need for soft and hard tissue augmentation was identified. Conclusions: Future research should clearly identify the clinical and patient benefits resulting from ridge preservation compared with traditional procedures. In addition, future research should also aim at better identifying parameters critical for positive treatment outcomes with immediate implants. The result of this procedure should be compared to early and late implant placement.

To retrospectively evaluate the survival rate of machined implants in sinus-lifted posterior maxilla after 12 years, with special reference to radiographic outcome and peri-implantitis.From 37 possible candidates, 29 patients with 59 implants were evaluated. Implants were placed in the posterior maxilla in combination with a sinus elevation procedure (27 patients) or 6 months after sinus elevation (2 patients). Marginal bone level changes were radiographically evaluated at baseline and 1, 7, and 12 years post-loading. Probing depth was measured; presence/absence of plaque and bleeding on probing were recorded.Four out of 59 implants failed in 4 out of 29 patients (cumulative survival rate = 93.2%). The mean bone loss was 0.78 mm (± 0.88) after 12 years. Changes in the mean bone level were statistically significant between baseline and all the other follow-up intervals (p .001). Statistically significant differences could be demonstrated for the first- to 12th-year interval (p .05) and for the seventh- to 12th-year interval (p 0.001). No statistically significant differences could be demonstrated at the first- to seventh-year interval (p = .32). The mean overall probing depth was 2.9 ± 0.66 mm. Probing depth was moderately correlated with the marginal bone changes at 7 year and after 12 year follow up (p = .05). No signs of peri-implantitis were reported during the 12-year follow-up period.This follow-up demonstrates a very good prognosis when implants with machined surfaces are used. The frequencies of implant failures were very small. Within the limits of the results from this study, the risk of peri-implantitis in the posterior maxilla might be considered a minor problem when implants with machined surfaces are used.

In common practice a perfect fit of the prosthetic framework with the implant abutments is almost impossible to achieve. The mismatch, which is principally induced by the technological process adopted to manufacture the fixed prostheses, strains the framework thus generating constraint reactions. These are static forces that load the implant components and the bone at the implant-bone interface and may cause the bone remodelling. Depending on the magnitude of such forces, i.e. depending on the magnitude of the mismatch, the bone remodelling may lead to the loosening of the screws and of the implant-bone interface and hence cause implant failure. The present study shows an in vitro comparison of 3 different connecting abutments (standard, EsthetiCone and CerAdapt, Nobel Biocare AB, Goteborg, Sweden) with relation to the mechanical stresses induced by geometrical mismatches (technology induced errors). Two experimental devices were purposely realized and used to assess the ability of the different abutments to compensate errors. One was designed for translation errors and the other for rotation errors. The experimental apparatus set-up includes 2 freestanding implants supporting a prosthetic structure and the connecting abutments. The implants and the abutments were used as delivered by the manufacturer, while the prostheses were purposely realized and instrumented with strain gauges. The data obtained with the error devices do not give quantitative information on what happens in clinical applications where the implants are connected to living bone, which is a tissue much more deformable than the steel used for the error devices. Results allow direct comparisons of the behaviour of the different investigated abutments with respect to position errors. The CerAdapt system (cement retained ceramic abutments) showed the least strain in presence of translation errors. The standard system (screw retained abutments) showed the least strain in presence of rotation errors.

A lack of information exists about the influence of different implant abutment materials on bacterial colonization and its role in the development of perimplantar infections. In order to study these aspects, removable acrylic devices, harboring samples of titanium and novel ceramic abutments (Nobel Biocare) were adapted to the molar-premolar region in 2 mandibular quadrants of 4 volunteers. Samples of each material were collected at 6 and 24 h, 7 and 14 days. Samples were observed by scanning electron microscopy and bacterial counts were made by means of ATP detection and direct plate count. The electron micrographs demonstrated that the bacteria colonization was already present after 6 h of presence in the oral cavity. After 24 h, both the materials were covered by several layers of bacterial cells. No differences in microbial colonization were observed between titanium and ceramic samples. The microbiological analysis confirmed the presence of relevant amounts of microbial cells on the tested samples. The maximum of colonization was achieved after 24 h in the oral cavity and the bacterial counts remained constant over the 14 day period. No significant differences were observed between the two materials analyzed in this study. In addition, ATP-bioluminescence technology was demonstrated to be a suitable system to evaluate bacterial colonization in the oral cavity.

The purpose of the present investigation was to study the histological morphology of the e-PTFE membrane/tissue interface in 5 humans subjected to GBR treatment in conjunction with oral implant treatment. Oral implants (Branemark System) were inserted in extraction sockets 1 to 2 months after extraction of periodontally diseased teeth. The implants were placed approximately 2 mm below the surrounding bone margins. Specially designed 3 mm high cover-screws with horizontal slits for tissue ingrowth were applied to the implants and covered with e-PTFE membranes (GoreTex Augmentation Material). Re-entry was made 7 months later, except in 1 case where the membrane was removed 1 month postoperatively due to exposure and infection. In the remaining 4 sites, circular biopsies comprising membranes, tissues and cover-screws were retrieved. The specimens were fixated, processed and sectioned for light- and transmission electron microscopy. The space between the membrane and the cover-screw was occupied by fibrous tissue and varying amounts of bone. A cell- and vessel-rich fibrous tissue separated the bone from the membrane in the majority of the specimens. The membrane itself was penetrated by fibrous tissue. Fibroblasts and macrophages were the main cell types found in the fibrous tissue. The presence of irregularly shaped cells and unevenly distributed collagen fibres, indicated that the absence of bone formation may be due either to micromovements in the e-PTFE/tissue interface or to formation of fibrous tissue underneath the membrane by penetrating fibroblasts or a combination of these 2 phenomena.

The aim of this study was to evaluate the characteristics of resorption and the pattern of bacterial collonisation of polyglycolic and polylactic resorbable membranes under controlled experimental conditions. A removable cobalt-chromium device was applied to the lower jaw of 5 students for a period of 4 weeks. 8 composite resin chambers were glued to the device, 4 on each side of the mouth. A small piece of PLA/PGA membrane separated the composite chambers into 2 parts. The subjects wore the devices 24 h a day, except for the time necessary for oral hygiene procedures, during which time, the structure was submerged in a 0.2% chlorexidine solution. Every week, 2 of the chambers were removed; one was processed for scanning electron microscopy, to be observed both on the external and internal surface, and the other one for light microscopy examination. Both the electron microscopic and histologic observations showed a progressive increase in the plaque layer on the external surface of the membrane during the period of observation. The light microscopy showed an early invasion of the membrane, starting about 1 week after the exposure. On all the 3- and 4-week specimens, a complete bacterial invasion over the whole thickness of the membrane was visible. After 3 weeks of plaque accumulation, bacterial colonisation of the inner portion of the membrane was detectable in all the specimens. At 3-weeks, we observed in the light microscopy group in 4 out of 5 specimens, a large reduction of the thickness of the material and small voids in the membrane structure. In 1 specimen, the membrane was no more detectable. Only in 5 specimens of the 4-week group was the membrane still recognizable, though reduced to fragments. In conclusion, once exposed to the oral cavity, the PLA/PGA membranes start to resorb in the early stages: this process concludes itself between the 3rd and 4th weeks of exposure. However, the particular conditions of the experimental design nevertheless classify this study as an in vitro, more than as an in vivo experimentation.

Premature exposure of membrane in the oral cavity is considered the most common complication as well as a reason for failure or incomplete success of guided tissue regeneration, as the exposed membrane undergoes plaque accumulation. A method to control, or at least to reduce the bacterial invasion of the membrane allowing a delay in the membrane removal, could be of clinical interest. The purpose of the present study was to evaluate the possibility of treating, with topical chlorhexidine application, the bacterial colonization of exposed membranes. A special device was developed in order to evaluate, under an experimental environment, the bacterial colonization. This device was made from a removable acrylic denture base to which 5 gold cups were attached. The cups consisted of an internal compartment, isolated from the oral cavity by a GTAM membrane, and an external compartment exposed to the oral environment. 3 healthy subjects had this device fitted, bilaterally, in the molar-premolar region of the upper jaw. The cups of one side of each subject had 0.2% chlorhexidine gluconate gel applied 2× a day for 1 min, whereas those of the other side served as controls. 12 cups were removed after 2 weeks and the remainder removed after 1 month. The non-treated control specimens were characterized by greater amounts of plaque accumulation. In all the test sites, plaque deposits increased in thickness and quantity during the 4 weeks of the experiment. Complete invasion of the membrane and initial colonization of its internal surface were observed only in 4-week specimens. A relatively simple flora consisting mainly of cocci and short rods, was found in bacterial deposits forming under the influence of chlorhexidine, whereas in non-treated specimens, it was possible to observe a more mature and complex plaque, composed mostly of filamentous bacteria. In conclusion, topical application of chlorhexidine gel is an effective method of reducing plaque and calculus formation on the surface of GTAM membranes exposed to the oral cavity for up to 4 weeks. This study has, however, failed to demonstrate the capacity of chlorhexidine to prevent or to retard bacterial penetration through the thickness of the inner portion of the membranes.

† The great majority of well-documented oralimplants show very good long-term clinical results.† A limited amount of crestal bone loss (CBL) ormarginal bone loss may be a biologic response toimplant placement.† CBL may occur for reasons other than infection.† CBL may occur around implants and can have along-termimpactontheoutcomeof thoseimplants.† Some implants can demonstrate substantial boneloss, but a steady state may be reached and nofurther clinically significant bone loss observed.† There is an adaptive change of the crestal bone levelafter placement and restoration.† Peri-implantitis is an unsuitable term to describe allCBL.† The term peri-implantitis is here defined as aninfection with suppuration associated with clini-cally significant progressing CBL after the adaptivephase.† In contrast, peri-implant mucositis is defined asinflammation of the peri-implant mucosa withoutdiscernibly progressing CBL.† Bone remodeling including CBL is influenced byinflammation.† Implant-, clinician-, and patient-related factors aswell as foreign body reactions may contribute toCBL. Implant factors: material, surface properties,and design (e.g., ease of plaque removal); clinicianfactors: surgical and prosthodontic experience,skills, and ethics; patient factors: systemic diseaseand medication, oral disease (e.g., untreated orrefractory periodontal disease, local infections),behavior (e.g., patient compliance with oral hygieneand maintenance, smoking), and site-related factors(e.g., bone volume and density, soft tissue quality);and foreign body reactions (e.g., corrosion by-products, excess cement in soft tissues).† A radiograph does not give an absolutely accuratepicture of the bone-implant contact or the crestalbone situation. However, the periapical radiographis an important clinical tool to be used at im-plant placement, implant loading, and repeatedlythereafter.† Radiographs taken longitudinally may assist the cli-nician to monitor changes in crestal bone levels.† Peri-implant examinations that include bleedingon probing and probing depths do not by

The aim of this case report is to histologically evaluate periapical healing after combined endodontic-periodontic treatment. A maxillary left central incisor was treated with conventional endodontic therapy, followed by periodontal surgery. The facial bony defect was filled with a mixture of autologous bone and Bio-Oss. A resorbable membrane was used. Histology showed the presence of new cementum, ligament, and bone around the apex of the treated tooth. This finding was clinically associated with minimal residual probing depth and maximum attachment gain. This histologic report demonstrates the possibility of true regeneration in a case of severe periodontal attachment loss resulting from an endodontic-periodontic lesion.

Soft tissue augmentation around dental implants in the esthetic region remains a challenging and unpredictable procedure. The ideal surgical technique would include of an off-the-shelf product to minimize morbidity after autogenous grafting procedures. The aim of this study was to use a resorbable collagen matrix (Mucograft) to serve as a scaffold to recombinant human platelet-derived growth factor BB (rhPDGF-BB) to increase peri-implant soft tissue volume in anterior maxillary sites. A total of six patients who had previously undergone a bone regeneration procedure were included in this study. The collagen matrix was applied during stage-two surgery (expanded polytetrafluoroethylene membrane removal and implant placement). Measurements were performed through customized stents by means of endodontic files, and at abutment connection, a soft tissue biopsy specimen was harvested for histologic examination. The healing period was uneventful in all six patients. Measurements were taken apically, centrally, and occlusally for each site. The mean gains in volume from baseline to the 4-month measurement at the apical, central, and occlusal aspects were 0.87 ± 2.13 mm, 2.14 ± 3.27 mm, and 0.35 ± 3.20 mm, respectively. The results showed a moderate increase in the soft tissue volume in esthetic peri-implant sites when applying a collagen matrix infused with rhPDGF-BB. However, the measuring techniques available need to be further improved to record exact changes in the soft tissue volume.

Autogenous soft tissue augmentation procedures around natural teeth and dental implants are performed daily by clinicians. However, patient morbidity is often associated with the second surgical site; hence, research is moving toward an era where matrices may substitute autogenous grafts. The aim of this study was to assess the soft tissue response to a collagen matrix in an animal model. Nine pigs were included in this study. Each animal received four collagen matrices, two for each mandible. Three cohorts were included in the study: group A, where the matrix was applied as an onlay on a partial-thickness flap; group B, where the matrix was inserted under a partial-thickness flap; and group C, where the matrix was inserted in an inverted position under a full-thickness flap. Sacrifice occurred at 7, 15, and 30 days postoperatively for histologic assessment. The collagen matrix was seen in place for the first 2 weeks, and it was completely replaced by healthy connective tissue within 30 days in the inlay cohorts. No inflammatory adverse reactions were noticed in any specimen, resulting in optimal integration of the device. This study showed an optimal integration within 30 days postoperative of the placement of experimental collagen matrix in the soft tissues of an animal model. Its proven safety in this model provides an optimal starting point for further research projects considering its clinical applications.

The technique of guided tissue regeneration using expanded polytetrafluoroethylene (ePTFE) membranes has been shown to be effective in implant dentistry (bony defects, extremely thin alveolar ridges, and implants placed in fresh extraction sockets). One of the drawbacks associated with the use of membranes is their premature exposure with consequent bacterial contamination. The aim of this study was to examine the possibility that oral bacteria migrate through the occlusive portion of ePTFE membranes and to determine the time needed for microorganisms to pass from the outer surface to the inner surface of the membranes. A removable acrylic device was adapted to the molar-premolar region of one quadrant of the jaws in each of three volunteers. Five cylindrical teflon chambers were glued to the buccal aspect of each device. The chambers were divided into two rooms separated by the inner portion of a ePTFE membrane. The outer room was open to the oral cavity allowing plaque accumulation; the inner room was isolated from the oral cavity by the ePTFE membrane. One of the 5 chambers was completely closed and used as control. The test period lasted for 4 weeks. Every week, one chamber was removed from each device and processed for scanning electron microscopic and histologic examinations. Our study showed the possibility that oral bacteria may contaminate ePTFE membranes exposed to the oral cavity. One specimen showed partial bacterial penetration after 2 and 3 weeks, but after 4 weeks, all membrane specimens demonstrated bacterial contamination.(ABSTRACT TRUNCATED AT 250 WORDS)

The goal of classifying complications in guided bone regeneration procedures with nonresorbable membranes is to provide the clinician with an instrument for easier identification of both the problem and treatment modality. A standardized terminology represents a key point for proper communication among clinicians and provides guidelines for managing these drawbacks.

The aim of the present study was to evaluate a Ca-P coated implant surface in a rabbit model. The Ca-P surface (test) was compared to the titanium porous oxide surface (control) in terms of bone-to-implant contact (BIC) and removal torque value.Two hundred and sixteen dental implants were inserted in the tibia and in the femur of 36 rabbits. One hundred and eight were represented by Ca-P oxidized surface implant and other 108 were titanium porous oxide surface modified implants. Each rabbit received six implants. Animals were sacrificed after 2, 4 and 9 weeks of healing. Each group included 12 rabbits. The femoral implant and the proximal implant of the tibia of each animal were subjected to the histologic analysis and the distal implants of the tibia underwent removal torque test (RTQ).Histological analysis in terms of BIC and RTQ did not revealed any significant difference between the Ca-P oxidized surface and the oxidized surface at 2 and 4 weeks. At 9 weeks, the oxidized surface demonstrated better results in terms of RTQ in the tibia.In conclusion, findings from the present study suggested that the Ca-P coating had no beneficial effect in improving bonding strength at the bone-implant interface either at 2, 4 and 9 weeks.

This preclinical study evaluated the efficacy of purified recombinant human platelet-derived growth factor (rhPDGF-BB), combined with a novel equine hydroxyapatite and collagen (eHAC) bone block, in providing vertical bone regeneration in critical-size defects simulating localized mandibular alveolar bone atrophy. In addition, the impact of barrier membrane placement in growth factor-mediated bone regeneration was also studied. Bilateral posterior mandibular defects simulating severe localized bony atrophy were created in 12 adult foxhounds following removal of all four mandibular premolars. Three months later, the defects were grafted as follows: group A: eHAC block alone; group B: eHAC block + collagen membrane; group C: eHAC block + rhPDGF-BB; group D: eHAC block + rhPDGF-BB + membrane. The animals were sacrificed after 5 months and the grafted areas were examined histologically, radiographically, and clinically. Groups A and B (controls) exhibited little to no vertical bone regeneration. Group C demonstrated significant vertical bone regeneration, with dense, well-vascularized bone, high bone-to-implant contact, and accelerated replacement of graft particles with newly formed bone. In group D, with the imposition of a barrier membrane, robust bone regeneration was less evident when compared to group C. As in the first study in this series, the importance of the periosteum as a source of osteoprogenitor cells in growth factor-mediated regenerative procedures is examined.