Analysis of ultra-short implants with different angulations: a retrospective case-control study with 2 to 9 years of follow-up.

OBJECTIVES: Does the angulation of ultrashort implants influence the stability of the peri-implant bone? The present study aimed to evaluate the effectiveness of non-axial ultrashort implants after 2 to 9 years of follow-up in resorbed alveolar ridges. MATERIALS AND METHODS: All partially edentulous patients with ultrashort implants (< 6 mm) used in the posterior region of an atrophic mandible or maxilla, to support partial dentures in conjunction with standard implants, were included in this study. Peri-implant bone loss, success and survival rates, crestal bone levels, crown-to-implant ratio and implant angulation were measured for each implant. Implants were divided into two groups: straight implants with angulation < 17° (control group) and tilted implants with angulation > 17° (test group). Statistical analysis was used to find any significant differences between the two study groups and to investigate significant linear correlations among all the variables (p = 0.05). RESULTS: A total of 42 ultrashort implants with a mean of 4 years of follow-up were included: 20 ultrashort axially loaded implants and 22 tilted implants. Mean crestal bone levels from baseline loading to maximum follow-up did not reveal statistical differences in regard to PBL; mean success and survival rates were 100% in all groups. CONCLUSIONS: PBL, success and survival rates of axial ultrashort implants and tilted ultrashort implants are comparable to those of conventional implants. CLINICAL RELEVANCE: This retrospective study revealed that ultrashort implants, even when placed with an angulation > 17°, can safely be used to support partial fixed prostheses. Further prospective clinical studies with larger samples and prospective design are needed to confirm these findings.

Histological and histomorphometric analysis of bone tissue using customized titanium meshes with or without resorbable membranes: A randomized clinical trial.

OBJECTIVES: To date, no clinical studies have investigated the effect of using resorbable collagen membrane in conjunction with customized titanium mesh to promote bone formation in guided bone regeneration. Therefore, a non-inferiority analysis (one-sided 95% CI approach) was designed to compare the augmented bone gained using meshes with and without collagen membranes, through histological and histomorphometric investigations. MATERIALS AND METHODS: Thirty patients undergoing bone augmentation procedures at both maxillary and mandible sites were randomly treated with customized titanium meshes alone (M-, n = 15) or covered with resorbable membrane (M+, n = 15), in both cases filled with autogenous bone and xenograft. After 6 months of healing, bone tissue biopsies were taken from the augmented region. The bone tissue (B.Ar), grafting material (G.Ar), and non-mineralized tissue (NMT.Ar) areas were quantified through histomorphometric analysis, as were the osteoid area (O.Ar) and its width. RESULTS: Collagen membrane did not appear to significantly influence the investigated parameters: B.Ar, G.Ar, NMT.Ar, and O.Ar were similar between Group M- (34.3%, 11.5%, 54.1%, 1.95 µm2 , respectively) and Group M+ (35.3%, 14.6%, 50.2%, and 1.75 µm2 , respectively). Considering the overall population, significantly higher rates of newly formed bone were obtained in mandibular sites, while non-mineralized and dense connective tissue rates were higher in the maxilla (p < .05). CONCLUSIONS: The application of collagen membrane over titanium mesh did not lead to significant results. Bone formation appeared significantly different in the maxilla compared with the mandible. Additional studies are required to further investigate the issues observed.

The influence of vertical ridge augmentation techniques on peri-implant bone loss: A systematic review and meta-analysis.

INTRODUCTION: The primary aim of this systematic review was to investigate and compare the outcomes of different vertical ridge augmentation (VRA) techniques in relation to peri-implant bone loss (PBL), after at least 12 months of functional loading. MATERIAL AND METHODS: The search was conducted to find all the studies about VRA and measurements of PBL with at least 12 months follow-up. Three pairwise meta-analysis (MA) was performed to completely evaluate the outcomes. RESULTS: A total of 42 studies were included, of which 11 were randomized clinical trials (RCTs). RCTs were available only for guided bone regeneration (GBR), onlay, and inlay techniques. The weighted mean estimate (WME) of PBL value was found to be 1.38 mm (95% confidence interval [95% CI]: 1.10-1.66) after a mean follow-up of 41.0 ± 27.8 months. GBR, Inlay, Onlay, osteodistraction, and SBB represented in weight 32.9%, 30.6%, 25.0%, 7.6%, and 3.9%, respectively; and their WME (95% CI) were 1.06 (0.87-1.26) mm, 1.72 (1.00-2.43) mm, 1.31 (0.87-1.75) mm, 1.81 (0.87-1.75) mm, and 0.66 (0.55-0.77) mm, respectively. Among the secondary outcomes, the analysis was conducted for vertical bone gain, healing complication rate, surgical complication rate, implant survival, and success rate. CONCLUSIONS: The primary findings of the meta-analysis, based on the changes between final and baseline values, showed that the peri-implant bone loss could be influenced by the type of intervention but there is a need to evaluate in RCTs the behavior of the peri-implant bone levels after long-term follow-up for all techniques.

Effectiveness of Bichat's Buccal Fat Pad (BFP) Technique for Vertical Ridge Augmentation in the Maxilla.

This study evaluated the efficacy of buccal fat pad (BFP) as a natural barrier to cover nonresorbable devices for vertical ridge augmentation (VRA). Twelve consecutive patients with 14 vertical bone defects in need of bone augmentation for implantprosthetic rehabilitation were treated according to the described protocol. VRA was performed by means of customized titanium meshes, titanium-reinforced d-PTFE membranes, or resorbable membranes and titanium plates. After buccal flap release, the BFP was identified and isolated, then mesially and coronally advanced to cover the whole augmented area. BFP was used as a pedicle flap in 11 cases and as a free graft in 3 cases. The mean BFP surface area was 13.5 ± 5.5 cm2. Healing was uneventful in all 14 augmented sites. No patients reported healing complications or facial volumetric changes. The mean vertical bone gain (VBG) was 4.2 ± 1.8 mm. In this limited number of cases, using the BFP as a natural barrier has proven to be efficient in bone augmentation, as it improved the healing process while reducing the risk of complications. Int J Periodontics Restorative Dent 2023;43:e99-e109. doi: 10.11607/prd.5473.

Vertical ridge augmentation with Ti-reinforced dense polytetrafluoroethylene (d-PTFE) membranes or Ti-meshes and collagen membranes: 3-year results of a randomized clinical trial.

BACKGROUND: The present study aimed to evaluate hard and soft tissue parameters around implants placed in augmented posterior mandible, comparing Ti-reinforced d-PTFE membranes with Ti-meshes covered with collagen membranes, after 3 years of follow-up. MATERIALS AND METHODS: Forty eligible patients were randomly assigned to group A (Ti-reinforced d-PTFE membrane) or group B (mesh covered with collagen membrane) for vertical ridge augmentation (VRA) and simultaneous implants. Implants were evaluated using specific peri-implant parameters for bone and soft tissues: probing pocket depth (PPD), modified plaque index (mPI), bleeding on probing (BoP), modified gingival index (mGI), thickness of keratinized tissue (tKT), width of keratinized tissue (wKT), fornix depth (FD), peri-implant bone level (PBL), interproximal bone peaks (IBP), marginal bone loss (MBL), interproximal bone loss (IBL). RESULTS: A total of 28 patients with 79 implants were evaluated after 3 years of follow-up. The mean value of MBL was 0.70 mm (group A = 0.73 mm; group B = 0.71 mm), while mean IBL was 0.54 mm (group A = 0.64 mm; group B = 0.40 mm). The treatment with meshes resulted not inferior to PTFE and their clinical results appeared similar. A strong correlation between PBL and IBP was confirmed. Both study groups showed an increase of tKT and wKT values. CONCLUSION: In the posterior mandible, VRA using both techniques provides stable PBLs up to 3 years. A correct soft tissue management and a strict professional oral hygiene protocol play a crucial role on peri-implant health over time.

Effectiveness Of Bichat's Buccal Fat Pad (BFP) Technique For Vertical Ridge Augmentation In The Maxilla.

The aim of this study was to evaluate the efficacy of buccal fat pads (BFP) as a natural barrier to cover nonresorbable devices for vertical ridge augmentation (VRA). A total of 12 consecutive patients with 14 vertical bone defects in need of bone augmentation for implant-prosthetic rehabilitation were treated according to the described protocol. VRA was performed by means of (1) customized titanium meshes, (2) titanium-reinforced PTFE membranes, or (3) resorbable membranes plus titanium plates. After buccal flap release, the BFP was identified, isolated, then mesially and coronally advanced to cover the whole augmented area. BFP was used as a pedicle flap in 11 cases and as free graft in 3 cases. The mean surface of the BFP obtained was 13.5 ± 5.5 cm2. In all 14 augmented sites, uneventful healing was assessed. No patients reported healing complications or facial volumetric changes. The mean VBG was 4.2 ± 1.8 mm. In this limited number of cases, the technique using the BFP as a natural barrier has proven to be efficient in bone augmentation, as it has shown to improve the healing process while reducing the risk of complications.

A novel technique for digitalisation and customisation of reinforced polytetrafluoroethylene meshes: Preliminary results of a clinical trial.

PURPOSE: To evaluate the clinical, radiographic and patient-related outcomes of a novel technique for digitalisation and customisation of reinforced polytetrafluoroethylene meshes in vertical ridge augmentation surgery. MATERIALS AND METHODS: A total of 10 patients (five men and five women, mean age 54 years) with vertical defects were included in the study. Prior to surgery, digital planning of bone augmentation, manufacturing of 3D printed models and replicas of the meshes and modelling of a customised reinforced polytetrafluoroethylene mesh were carried out. All patients were treated using a 50:50 mixture of xenogeneic and autogenous bone, customised reinforced polytetrafluoroethylene mesh and collagen membrane. After 6 to 9 months, computer-guided surgery was planned, the reinforced polytetrafluoroethylene mesh was removed and implants were placed in augmented sites using a fully guided surgical template. Patient-related outcomes, intraoperative timing, surgical and healing complications, vertical bone gain, bone density, pseudoperiosteum type and number and stability of implants were recorded. RESULTS: All 10 patients were treated without surgical complications. Healing was largely uneventful, with the exception of one case of abscess formation without mesh exposure (exposure rate 0%). The mean duration of digital planning was 17.0 minutes, reinforced polytetrafluoroethylene mesh customisation took 9.0 minutes, and the total intraoperative time was 91.3 minutes. The mean planned bone volume was 1.52 cc, vertical bone defect depth was 6.0 ± 1.7 mm and vertical bone gain was 5.5 ± 1.9 mm; most sites showed medium bone density and a Type 1 pseudoperiosteum. All patient-related outcomes were favourable. CONCLUSIONS: The preliminary results of this pilot study demonstrated the feasibility and reliability of a fully digital workflow for the customisation of reinforced polytetrafluoroethylene mesh in vertical ridge augmentation.

Vertical and horizontal ridge augmentation using customized CAD/CAM titanium mesh with versus without resorbable membranes. A randomized clinical trial.

OBJECTIVES: The aim was to evaluate the role of resorbable membranes applied over customized titanium meshes related to soft tissue healing and bone regeneration after vertical/horizontal bone augmentation. MATERIALS AND METHODS: Thirty patients with partial edentulism of the maxilla/mandible, with vertical/horizontal reabsorption of the alveolar bone, and needing implant-supported restorations, were randomly divided into two groups: Group A was treated using only custom-made meshes (Mesh-) and Group B using custom-made meshes with cross-linked collagen membranes (Mesh+). Data collection included surgical/technical and healing complications, "pseudo-periosteum" thickness, bone density, planned bone volume (PBV), regenerated bone volume (RBV), regeneration rate (RR), vertical bone gain (VBG), and implant survival in regenerated areas. Statistical analysis was performed between the two study groups using a significance level of α = .05. RESULTS: Regarding the healing complications, the noninferiority analysis proved to be inconclusive, despite the better results of group Mesh+ (13%) compared to group Mesh- (33%): estimated value -1.13 CI-95% from -0.44 to 0.17. Superiority approach confirmed the absence of significant differences (p = .39). RBV was 803.27 mm3 and 843.13 mm3 , respectively, and higher RR was observed in group Mesh+ (82.3%) compared to Mesh- (74.3%), although this value did not reach a statistical significance (p = .44). All 30 patients completed the study, receiving 71 implants; 68 out of them were clinically stable and in function. CONCLUSION: The results showed that customized meshes alone do not appear to be inferior to customized meshes covered by cross-linked collagen membranes in terms of healing complication rates and regeneration rates, although superior results were observed in group Mesh+compared to group Mesh- for all variables.

A microcomputed tomography analysis of bone tissue after vertical ridge augmentation with non-resorbable membranes versus resorbable membranes and titanium mesh in humans.

PURPOSE: Guided bone regeneration is a frequently used surgical procedure for hard tissue reconstruction when horizontal and or/vertical augmentation are needed. The treatment concept is based on the application of occlusive membranes like non-resorbable membranes or titanium mesh plus resorbable membranes. However, there are no studies comparing the microcomputed tomography results for bone obtained using these two procedures, and this was the purpose of the present study. MATERIALS AND METHODS: A total of 40 patients with vertical posterior bone mandibular atrophy were randomly assigned to group A (guided bone regeneration with titanium-reinforced polytetrafluoroethylene membrane and simultaneous implant placement) or group B (guided bone regeneration with titanium mesh and collagen membrane and simultaneous implant placement). Tissue biopsy specimens were obtained from augmented sites after 9 months for microcomputed tomography analysis of volume of interest. Bone volume (BV/TV), biomaterial volume (MatV/TV), soft tissue volume (StV/TV), trabecular thickness (TbTh), trabecular number (TbN) and trabecular separation (TbSp) were measured. The correlation between regenerated bone and native bone was also evaluated. STATA software (StataCorp, College Station, TX, USA) was utilised for statistical analysis (significance α = 0.05). RESULTS: In group A, the values of BV/TV, MatV/TV and StV/TV in regenerated bone were 28.8%, 8.9% and 62.4%, respectively. In group B, the values of BV/TV, MatV/TV and StV/TV were 30.0%, 11.0% and 59.0%, respectively. No statistical differences were found between the two groups for any of the variables (P < 0.05). In both groups, considerable differences were noted between regenerated and native bone (P > 0.05), with a slight correlation between the microcomputed tomography parameters that suggests that native bone influences the quality of regenerated bone. CONCLUSIONS: Based on microcomputed tomography analysis, both surgical approaches facilitated the obtention of approximately 30% of newly formed bone with the same microarchitecture. Native bone influences the quality and microarchitecture of the obtained bone, irrespective of the technique used.

Patient-reported outcomes and complication rates after lateral maxillary sinus floor elevation: a prospective study.

OBJECTIVES: Oral surgery morbidity is highly variable based on patients' characteristics and kind of surgical intervention. However, poor data are available in the literature regarding patient outcomes after oral surgery. The aim of this retrospective study was to evaluate patient-reported outcome and complication rates after maxillary sinus floor elevation. MATERIALS AND METHODS: Data from the records of patients undergoing maxillary sinus elevation have been collected from a private dental office. Patient-reported outcome has been assessed using a 100-mm visual analog scale to evaluate the post-operative pain (VASpain) experienced in the first week following surgery and visual rating scales to evaluate discomfort level (VRSdiscomfort: 0 to 4) and willingness to repeat the same surgical procedure (VRSwillingness: 0 to 3). Analgesics intake, swelling onset and duration, and ecchymosis have been also recorded. RESULTS: VASpain showed moderate values in the first 2 days (< 50) post-surgery, with a tendency to progressively decrease over the next 2 days. Average assumption of painkillers was 3.93 ± 3.03. Discomfort level (VRSdiscomfort) after surgery was low (median: 1; IR: 1-0), while willingness to undergo the same surgical procedure was very high (77.63% of patients). Swelling and ecchymosis were experienced by 97.36% and 51.32% of patients, respectively, with a mean duration of 4.09 ± 1.43 and 2.21 ± 2.31 days, respectively. Membrane perforation occurred in 4 cases. Other post-operative complications were not observed. CONCLUSIONS: Maxillary sinus grafting is a safe procedure, with a low complication rate and moderate morbidity that is well tolerated by patients. Particular attention is needed in case selection, surgical planning and operator expertise. CLINICAL RELEVANCE: The analysis of patient-reported outcomes can be of great help in surgical planning and in providing correct and adequate treatment.

Vertical ridge augmentation (VRA) with Ti-reinforced d-PTFE membranes or Ti meshes and collagen membranes: 1-year results of a randomized clinical trial.

OBJECTIVES: The aim of this study was to evaluate hard and soft tissues around implants placed in posterior mandible 1 year after vertical ridge augmentation (VRA). MATERIALS AND METHODS: 40 patients with vertical defects were enrolled and treated according to the study protocol. Patients were randomly divided into two study groups: reinforced PTFE membranes (group A) and titanium meshes plus collagen membranes (group B). All patients received simultaneous implants which were evaluated after prosthetic restoration at baseline and after 1 year, using the following parameters: peri-implant bone levels (PBLs), interproximal bone peaks (IBPs), pocket probing depth (PPD), bleeding on probing (BoP), plaque index (mPI), gingival index (mGI), keratinized tissue thickness/width (tKT and wKT), and fornix depth (FD). Statistical analysis was performed to investigate any statistically significant differences and/or correlations (p = .05). RESULTS: 30 patients were completely followed up according to the study protocol. After 1 year, implants showed a change in PBL from 0.12 to 0.76 mm, with marginal bone loss of 0.67 and 0.61 mm for group A and group B, respectively, without significant differences (p > .9337). The estimated difference between treatments for the change from baseline in PBL was -0.05 (95% CI -0.27 to 0.16). Statistical analysis revealed strong correlations between PBL and IBP (p < .0001). However, no significant differences were observed for PPD, mPI, mGI, tKT, wKT, and FD (p > .05). CONCLUSION: The results indicate that GBR treatment with titanium meshes plus collagen membranes (Group B) compared to reinforced PTFE membranes does not appear to be inferior or superior in terms of PBL change. In both groups, hard and soft tissues were stable after 1 year of follow-up, with a peri-implant bone loss less than 1.0 mm in the first year (study registered at ClinicalTrials.gov NCT04332679).

Clinical and volumetric outcomes after vertical ridge augmentation using computer-aided-design/computer-aided manufacturing (CAD/CAM) customized titanium meshes: a pilot study.

BACKGROUND: One of the most recent innovations in bone augmentation surgery is represented by computer-aided-design/computer-aided-manufacturing (CAD/CAM) customized titanium meshes, which can be used to restore vertical bone defects before implant-prosthetic rehabilitations. The aim of this study was to evaluate the effectiveness/reliability of this technique in a consecutive series of cases. METHODS: Ten patients in need of bone augmentation before implant therapy were treated using CAD/CAM customized titanium meshes. A digital workflow was adopted to design virtual meshes on 3D bone models. Then, Direct Metal Laser Sintering (DMLS) technology was used to produce the titanium meshes, and vertical ridge augmentation was performed according to an established surgical protocol. Surgical complications, healing complications, vertical bone gain (VBG), planned bone volume (PBV), lacking bone volume (LBV), regenerated bone volume (RBV), average regeneration rate (RR) and implant success rate were evaluated. RESULTS: All augmented sites were successfully restored with definitive implant-supported fixed partial dentures. Measurements showed an average VBG of 4.5 ± 1.8 mm at surgical re-entry. Surgical and healing complications occurred in 30% and 10% of cases, respectively. Mean values of PBV, LBV, and RBV were 984, 92, and 892 mm3, respectively. The average RR achieved was 89%. All 26 implants were successfully in function after 1 year of follow-up. CONCLUSIONS: The results of this study suggest that the bone augmentation by means of DMLS custom-made titanium meshes can be considered a reliable and effective technique in restoring vertical bone defects.

Influence of crown-implant ratio on implant success rate of ultra-short dental implants: results of a 8- to 10-year retrospective study.

OBJECTIVES: The use of short implants has been suggested in recent years as an option for facilitating prosthetic restoration in resorbed jawbones. The aim of the present study was to determine how implant success rate is affected in the long term when ultra-short implants are rehabilitated with fixed restorations, resulting in a crown to implant (C/I) ratio of more than 3:1. MATERIALS AND METHODS: The study was conducted as an analysis on all patients operated from December 2005 to November 2007 with ultra-short dental implants. All implants were sintered porous-surfaced (SPS) with a length of 5 mm and a diameter of 5 mm (5 × 5 mm) and were restored with a single crown or a fixed dental prosthesis (FDP). Data collected included implant positioning site, crestal bone levels (CBL), and clinical and anatomical C/I ratios, and pre-established success criteria were used to evaluate the success rate of the implants. Statistical analysis was used to determine any significant differences or correlations (p = 0.05). RESULTS: Forty-one patients completed the follow-up and were eligible for this retrospective study on a total of 50 ultra-short SPS implants. The mean follow-up was 9.5 years (range 8.3 to 10.2 years). Three of the 50 implants failed because they were lost due to peri-implantitis, while all the other 47 met the pre-established success criteria giving an overall implant success rate of 94%. During the follow-up period, the mean peri-implant bone loss (PBL) was 0.41 + 0.36 mm. CONCLUSIONS: This study shows that ultra-short SPS implants can prove a reliable solution for prosthetic restoration in patients with severe alveolar bone atrophy. In selected patients with a sufficient bone width, ultra-short implants with a resulting C/I ratio of more than 3:1 presented no contraindications. CLINICAL RELEVANCE: In selected cases, ultra-short implants may represent an alternative to bone augmentation procedures and a long-term predictable solution.

Solid index impression protocol: a hybrid workflow for high accuracy and passive fit of full-arch implant-supported restorations.

AIM: The purpose of this article is to present the preliminary clinical results obtained with a novel hybrid digital-analog technique, the solid index impression protocol (SIIP), which uses a solid index to capture accurate impressions of multiple implants for the fabrication of implant-supported fixed full arches (FFAs). MATERIALS AND METHODS: This pilot study was based on five patients, each treated with a FFA supported by four implants. Three months after implant placement, impressions were taken for all patients with an intraoral scanner (IOS) (direct digital impression) and with the SIIP, using a custom tray consisting of four hollow cylinders connected with a bar. This index was linked to the implant transfers and transferred to the laboratory, and the definitive FFAs were fabricated based on it. The outcomes of the study were the passive fit of implant superstructures and the accuracy of the models generated by the SIIP, inspected using a coordinate measuring machine (CMM) and reverse engineering software, and compared with the accuracy of direct digital impressions. RESULTS: Excellent clinical precision and passive fit were obtained in all five implant-supported FFAs fabricated with the SIIP. One year after delivery, all FFAs were functional without any complication. Differences in accuracy were found between the SIIP and direct intraoral scanning. CONCLUSIONS: The SIIP seems to represent a viable option for capturing accurate impressions for the fabrication of clinically precise implant-supported FFAs with a hybrid digital-analog workflow. Further studies are needed to confirm these results.

Evaluation of Crestal Bone Loss Around Straight and Tilted Implants in Patients Rehabilitated by Immediate-Loaded Full-Arch All-on-4 or All-on-6: A Prospective Study.

The aim of this prospective study was to compare implant success rate and crestal bone loss around tilted and straight implants supporting immediate-loading full-arch rehabilitations. Twenty consecutive patients with edentulous jaws treated between June 2013 and July 2015 who satisfied all inclusion and exclusion criteria were included in the study. All patients were rehabilitated through a full-arch restoration supported by 4 or 6 immediately loaded implants. Clinical and radiographic examinations were scheduled every 12 months to evaluate implant success rates and crestal bone levels. Significant differences in crestal bone levels and success rates between straight and tilted implants were investigated by means of independent statistical analysis; differences were regarded as significant if P < .05. Seventy straight and 50 tilted implants were placed to rehabilitate 14 mandibles and 12 maxillae in 20 patients. After a follow-up of 12 to 36 months, survival rate was 97.1% for straight implants and 96.0% for tilted implants; while success rates were 94.3% and 94.0%, respectively. Success and survival rates were not significantly different (P > .05). Change in crestal bone level was 0.5 ± 0.4 mm for straight implants and 0.6 ± 0.4 mm for tilted implants (P > .05). Straight and tilted implants seemed to have similar behavior after immediate loading rehabilitations. After functional loading, straight and tilted implants did not differ significantly in clinical outcome.

Statements and Recommendations for Guided Bone Regeneration: Consensus Report of the Guided Bone Regeneration Symposium Held in Bologna, October 15 to 16, 2016.

INTRODUCTION: In the past 10 years, long-term studies have demonstrated that guided bone regeneration (GBR) is a successful and reliable technique for vertical and horizontal ridge augmentation, but strict and rigorous protocols must be adopted. MATERIAL AND METHODS: Because no reports have yet been published with statements and clinical recommendations for GBR, a closed meeting of all authors was organized to discuss this matter during a GBR symposium held in Bologna (Italy) in October 2016. The authors focused on the findings of systematic and narrative reviews, prepared before the meeting, covering aspects of the clinical management of GBR techniques. Successively, a discussion based on the scientific evidence and on the experts' opinions led to the formulation of statements, clinical recommendations, and implications for future research. RESULTS: To avoid complications and to optimize outcomes, the following factors should be considered by clinicians: patient selection; analysis of defect type; blood supply; antibiotic treatment; flap passivation; delayed implant placement; combination of autogenous bone and xenograft or allograft; rigorous fixation of membranes; removal after 6 to 9 months; analysis of complications; soft-tissue management; and high care in scarred sites and in esthetic areas. CONCLUSIONS: The present consensus report reviewed the scientific evidence and provided specific guidelines and recommendations for clinical practice and the different approaches to GBR techniques to ensure surgical success and predictable outcomes.

Histological and histomorphometric analysis of bone tissue after guided bone regeneration with non-resorbable membranes vs resorbable membranes and titanium mesh.

BACKGROUND: Guided bone regeneration (GBR) allows to achieve vertical ridge augmentation whether with nonresorbable membranes or resorbable membranes with Ti-mesh, but till now no studies are published comparing histological and histomorphometrical outcomes of these two procedures. MATERIALS AND METHODS: Forty partially edentulous patients required vertical bone regeneration to place implants in the posterior mandible: 20 patients were randomly assigned to group A (Ti-PTFE); while 20 patients to group B (Collagen plus Ti-mesh). For both groups, graft material was a 50:50 mixture of autogenous bone and bone allograft. After 9 months, tissue biopsies were taken from augmented sites (regenerated bone ROI-1; native bone ROI-2) and undergone to histological and histomorphometric analysis. Percentages of bone tissue (B.Ar), biomaterial (Mat. Ar), and soft tissue (St.Ar) were measured; measurements of perimeters were calculated too. ROI-1 values were also compared to ROI-2 in both groups. RESULTS: Twenty-five samples were collected and analyzed consecutively: 13 in group A and 12 in group B. The mean B.Ar, Mat.Ar, and St.Ar were 39.7%, 8.6%, and 52.1% in group A; similar results were obtained in group B, with mean values of 42.1%, 9.6%, and 48.3%, respectively. No significant statistically differences were observed. Differences were observed between ROI-1 and ROI-2 in both group. Finally, bone structure index of ROI-1 and ROI-2 showed statistical differences. CONCLUSIONS: The preliminary results of this study suggest that GBR using nonresorbable membranes and Ti-mesh with resorbable membranes in combination with autogenous bone and bone allograft provide similar histological and histomorphometric results.

A Proposal of Pseudo-periosteum Classification After GBR by Means of Titanium-Reinforced d-PTFE Membranes or Titanium Meshes Plus Cross-Linked Collagen Membranes.

After guided bone regeneration (GBR) with different devices, a layer of connective tissue called pseudo-periosteum can be observed above the newly formed bone. The aim of this study is to evaluate the clinical and histologic features and to suggest a classification of this connective tissue after GBR with nonresorbable membranes or titanium (Ti)-mesh plus resorbable membranes. Forty patients with partial edentulism in the posterior mandible were randomized into two groups: 20 patients were treated by means of Ti-reinforced dense polytetrafluoroethylene (d-PTFE) membrane (group A), while the other 20 patients were treated with Ti-mesh and a cross-linked collagen membrane (group B). After 9 months and during re-opening surgery, bone density and pseudo-periosteum type were recorded. Pseudo-periosteum was classified into Type 1 (no tissue or tissue < 1 mm); Type 2 (regular tissue between 1 and 2 mm); and Type 3 (irregular tissue or tissue > 2 mm). Histologic analyses were performed to identify the features of pseudo-periosteum. Out of 40 patients, 36 (n = 19 in Group A; n = 17 in Group B) with 99 implants were analyzed after GBR and according to the study protocol. The vertical bone gain was 4.2 ± 1.0 mm in Group A and 4.1 ± 1.0 mm in Group B. Group A had a higher bone density and greater amounts of type 1 periosteum than Group B (P = .01 for both). The preliminary results of this study show that both d-PTFE membranes and Ti-mesh plus collagen membranes are two valid options for bone augmentation in the mandible. However, nonresorbable membranes achieve higher bone density and a thinner pseudo-periosteum layer above the newly formed bone.

In Vitro Effect of Bromelain on the Regenerative Properties of Mesenchymal Stem Cells.

BACKGROUND: Bromelain belongs to a group of protein-digesting enzymes obtained commercially from the fruit or stem of pineapple. Several studies demonstrated that bromelain exhibits various fibrinolytic, anti-edematous, antithrombotic, and anti-inflammatory activities supporting its application for many therapeutic benefits. The aim of this study was to analyze the effects of bromelain on the pro-wound healing activities and the regenerative properties of mesenchymal stem cells. METHODS: Mesenchymal stem cells were treated in vitro with bromelain alone or combined with dexamethasone sodium phosphate. Real-time polymerase chain reaction was performed to profile the expression of extracellular matrix components and remodeling enzymes, and cytokines. RESULTS: The combination of bromelain and dexamethasone sodium phosphate induced a great activation of mesenchymal stem cells with an increase in hyaluronan and collagen production and anti-inflammatory cytokines release. CONCLUSION: Based on the results of this in vitro study, the combined use of bromelain and dexamethasone sodium phosphate stimulated the pro-wound healing activities and the regenerative properties of mesenchymal stem cells better than bromelain and dexamethasone alone.