6-month Healing Period Research Articles

Healing patterns of alveolar bone following ridge preservation procedures.

Examine the histomorphometric bone composition, following alveolar ridge preservation techniques and unassisted socket healing. Forty-two patients (42) requiring a single rooted tooth extraction were randomly allocated into three groups (n = 14 per group): Group 1: Guided Bone Regeneration (GBR) using deproteinised bovine bone mineral (DBBM) and a porcine collagen membrane; Group 2: Socket Seal (SS) technique using DBBM and a porcine collagen matrix; Group 3: Unassisted socket healing (Control). Trephined bone biopsies were harvested following a 4-month healing period. Forty-two samples underwent Back-Scattered Electrons -Scanning Electron Microscopy (BSE-SEM) imaging, with 15 samples examined using Xray Micro-Tomography (XMT) (n = 6 for each GBR/SS and n = 3 Control). Images were analysed to determine the percentage (%) of connective tissue, new bone formation, residual DBBM particles and direct bone to DBBM particle contact (osseointegration). BSE-SEM analysis demonstrated that new bone formation was higher in the Control (45.89% ± 11.48) compared to both GBR (22.12% ± 12.7/p < .004) and SS (27.62% ± 17.76/p < .005) groups. The connective tissue percentage in GBR (49.72% ± 9), SS (47.81% ± 12.57) and Control (47.81% ± 12.57) groups was similar. GBR (28.17% ± 16.64) and SS (24.37% ± 18.61) groups had similar levels of residual DBBM particles. XMT volumetric analysis indicated a lower level of bone and DBBM particles in all test groups, when matched to the BSE-SEM area measurements. Osseointegration levels (DBBM graft and bone) were recorded at 35.66% (± 9.8) for GBR and 31.18% (± 19.38) for SS. GBR and SS ARP techniques presented with less bone formation when compared to unassisted healing. GBR had more direct contact/osseointegration between the DBBM particles and newly formed bone.

Half- and full-grafting alveolar ridge preservation with different sealing materials: A three-arm randomized clinical trial.

The objective of this study is to investigate the effect of different alveolar ridge preservation (ARP) approaches on bone resorption and their potential for facilitating implant placement. Patients who underwent one or two tooth extractions with a desire for restoration were included in the study. The participants were randomly assigned to one of three groups for ARP. The groups were as follows: (1) Half grafting of bovine bone mineral (DBBM-C) covered with non-resorbable dense polytetrafluoroethylene (dPTFE) membrane (Test 1 group); (2) Half grafting of bovine bone mineral (DBBM-C) covered with collagen membrane (Test 2 group); and (3) Full grafting with collagen membrane (DBBM-C + Collagen membrane) as the Control group. After 6-month healing period, the evaluation encompassed clinical, radiographic, implant-related outcomes, and the factors contributing to hard and soft tissue alterations. Enrollment in this study comprised 56 patients. At the 6-month follow-up, radiographic analysis in computed beam computed tomography images was conducted for 18, 19, and 19 patients with 18, 20, and 20 tooth sites in Test 1, Test 2, and Control groups, respectively. Additionally, a total of 15, 17, and 17 patients with 15, 18, and 17 implants were evaluated. Based on radiographic analysis, all groups showed limited ridge resorption at 1 mm from crest horizontally (Test 1: 1.29 ± 1.37; Test 2: 1.07 ± 1.07; Control: 1.54 ± 1.33 mm, p = 0.328), while the Control group showed greater radiographic bone height gain in mid-crestal part vertically (Test 1: 0.11 ± 1.02; Test 2: 0.29 ± 0.83; Control: -0.46 ± 0.95 mm, p = 0.032). There were no significant intergroup differences in terms of keratinized mucosal width, bone density, insertion torque, and the need of additional bone graft. However, the use of a dPTFE membrane resulted in a significantly higher vertical mucosal thickness (Test 1: 2.67 ± 0.90; Test 2: 3.89 ± 1.08; Control: 2.41 ± 0.51 mm, p < 0.001). The study showed comparable dimensional preservation with limited vertical shrinkage, while thin buccal bone plate, non-molar sites, and large discrepancy between buccal and palatal/lingual height may contribute to greater shrinkage. Thicker mucosa with dPTFE membrane required further investigation for interpretation. NCT06049823. This clinical trial was not registered prior to participant recruitment and randomization.

Three-Dimensional Analysis of Bone Remodeling After Closed Treatment for Mandibular Condylar Head Fracture.

Closed treatment of mandibular condylar fractures has been used for its indications based on the fracture site, fracture status, and patient age. Posttreatment mandibular condyle size is associated with mandibular function; however, a few studies have reported bone remodeling patterns and volume changes in the condyle and glenoid fossa after mandibular condylar head fractures (CHFs). Therefore, volumetric changes in the mandibular condyle and glenoid fossa were analyzed in the present study, and bone remodeling patterns were evaluated after mandibular CHFs. The present study included 16 condyles from 12 patients who received closed treatment for CHF. After reconstruction of a 3-dimensional skull model, including the mandible, using computed tomography data taken immediately after injury and 6 months after treatment, volume changes in the mandibular condyle and glenoid fossa were analyzed. The condylar volume increased by 0.32±0.66cm3 during the 6-month healing period without statistical significance (P=0.093). Regarding the glenoid fossa, the fossa showed a statistically significant volume increase of 0.41±0.59cm3 (P=0.021), and 12 glenoid fossae (75%) showed downward bone apposition; however, no change or only mild bone resorption was observed in 4 glenoid fossae (25%). The results of this study indicated that the volume changes in the mandibular condyle after closed treatment of a mandibular CHF are not significant, and the glenoid fossa adapts to the displaced mandibular condyle through downward growth accompanied by volume increase.

Immediate repair of bony defects in the posterior mandibular region following removal of a fractured implant: a feasible treatment?

The aim of this study was to assess whether immediate bone reconstruction after removal of a fractured dental implant in the posterior mandible provides a sound base for implant replacement, with a favourable treatment outcome and high patient satisfaction. Eight consecutive patients with a fractured implant neck were included. The implant was removed via osteotomy, following which the site was immediately repaired with a mixture of autogenous bone and bone substitute. After a 4-month healing period, sufficient bone and favourable soft tissue conditions were present, allowing implant placement with adequate primary stability. After a further 3 months, the implants were restored with an all-ceramic restoration. Patient satisfaction, the aesthetic outcome, complications, and postoperative morbidity were assessed using standardized clinical and radiographic examinations up to 5 years after crown placement. No implant failures were observed during the follow-up. Plaque accumulation, the presence of calculus, bleeding tendency, and peri-implant inflammation indices were low, indicating healthy peri-implant conditions. The mean marginal bone level change at the 5-year follow-up was − 0.17 ± 0.46 mm. All patients reported a high level of satisfaction (mean overall score 9.3 ± 0.5). In conclusion, immediate reconstruction of the hard tissue after removal of a fractured dental implant is a viable treatment option. This approach facilitates rehabilitation, reduces morbidity, and leads to favourable aesthetic outcomes.

Maxillary bone augmentation with calvarial bone graft for immediate full-arch rehabilitation: Insights from a 10-year proof-of-concept retrospective analysis.

Evaluate the long-term outcomes of full-arch rehabilitation using immediate dental implant placement and continuous functional loading with full-fixed dental prostheses (FFDPs). Fifty-six patients received temporary implants (n = 327) at maxillary augmentation with calvarial bone. A provisional acrylic FFDP was immediately loaded onto these implants. After 6 months, the temporary implants were replaced with definitive implants (n = 326) and immediately loaded with a second provisional FFDP (N = 55). Subsequently, a baseline radiograph was taken following a 6-month healing period. The second bridge was then substituted with a definitive FFDP. Primary outcomes included peri-implant marginal bone level (MBL) and definitive implant survival. Secondary outcomes evaluated provisional implant and prostheses survival, complications, and patient satisfaction. The provisional implants had a survival rate of 97.9%. One patient was excluded from further analysis due to loss of temporary implants and first FFDP. The definitive implant survival rate after 10 years was 92.2%, with a moderate but significant decrease in MBL between baseline radiography and 10 years later (-0.08 ± 0.18 vs. -0.24 ± 0.44). However, large individual variations were observed, with 65.8% of implants showing no bone loss and 9.2% showing loss ≥0.5 mm. Sinusitis was experienced by 14.3% of patients upon surgery. Patient satisfaction was high or reported no issues after protocol completion (80%). One patient lost all six definitive implants and definitive FFDP 8.2 years after implant placement. The described protocol can be regarded as a long-term, highly successful method for full-arch rehabilitation of atrophied maxillae while enabling continuous masticatory and speaking functionality.

Hard and soft tissue healing around implants with Ag coating: An experimental study in dogs

Introduction The purpose of this randomized controlled canine experimental study was to evaluate peri‑implant hard and soft tissue healing around implants with silver coating.Methods All mandibular premolars and molars of five male beagle dogs were extracted. 25 test and 25 control implants were randomly installed and connected with the healing abutments. After 2 and 4 month healing period, implants with soft and hard tissues were obtained for histologic and histomorphometric analysis.Results In mesio-distal sections, supracrestal tissue attachment dimensions were 4.03±0.48 mm and 4.25±0.66 mm for test and 4.34±0.6 mm and 5.21±0.72 mm for control implants at 2 and 4 month healing time. The respective crestal bone loss values were 1.10±0.69 mm and 0.74±0.67 mm for test and 1.13±0.48 mm and 1.49±0.65 mm for control implants. The differences were statistically significant only in the 4-month healing period. In buccolingual sections, supracrestal tissue attachment height at 2 and 4 month healing periods were 4.09±0.64 mm and 4.5±0.8 mm for test implants and 4.17±0.76 mm and 4.48±0.76 mm for control implants. The respective mean values for crestal bone loss were 1.31±0.6 mm and 1.02±0.58 mm for test implants, and 1.28±0.61 mm and 1.29±0.69 mm for control implants. No statistical significant differences were recorded, apart from the height of connective tissue at the 2 month healing group. No significant difference in terms of BIC between implants or healing periods was recorded.Conclusions The Ag implant coating resulted in smaller supracrestal tissue attachment dimensions and less bone loss. Within the limits of a canine study, prevention of crestal bone loss along with the effectiveness of Ag antimicrobial properties in dental implantology is demonstrated.

Biomolecular Mechanisms and Case Series Study of Socket Preservation with Tooth Grafts.

Twenty patients requiring tooth extraction underwent socket preservation utilizing the extracted tooth as the grafting material. After a 4-month healing period, the defects were significantly filled with newly formed hard tissue. Subsequently, bone biopsies were performed during dental implant placement to evaluate histological outcomes. The tissue exhibited a similar density to medium-density bone, displaying a homogeneous and uniform appearance without any visible signs of inflammation. The post-operative healing phase was free from infective complications or indications of graft particles within the regenerated bone structure. The histomorphometric analyses revealed the following results: bone total volume, BV% 52.6 ± 13.09, vital bone VB% 40.39 ± 15.86, residual graft % 12.20 ± 12.34. The study demonstrated positive bony healing in guided regenerative surgery procedures using autologous tooth grafts. However, further research with an extended follow-up period is necessary to thoroughly assess the potential of demineralized dentin autografts.

Evaluating the Benefits of Platelet Rich-Fibrin in Periodontal Regeneration: A Literature Review

Introduction: Platelet Rich-Fibrin (PRF) is a biological matrix derived from a patient’s own blood, rich in growth factors and platelets. Its use in various periodontal and non-periodontal procedures is gaining recognition due to its potential in promoting tissue regeneration. The purpose of this review was to evaluate the benefits of using PRF in intra-bony defect regeneration, guided-bone regeneration, and sinus floor elevation. Methods: The study searched PubMed for manuscripts published between 2017 and 2022 to better understand the clinical and radiological effects of PRF. The manuscripts were divided into the following sections: intra-bony defect regeneration, guided-bone regeneration, and sinus floor elevation. Results: In intra-bony defects, PRF improved clinical and radiological parameters when compared with OFD alone, with a significant difference in wound healing at 7 days. In GBR, a CBCT evaluation shows no statistical difference between the PRF-autogenous bone complex group and the bovine bone-collagen membrane complex regarding volume change of the augmented bone with a 16% rate of bone loss following a 6-month healing period. Also, a slight increase in bone thickness has been seen when liquid PRF is used. In sinus floor elevation, results revealed no differences in graft volume between PRF group and control group at any of the evaluated time points. Although higher implant stability immediately postoperatively, higher new bone formation, the lesser amount of residual graft and earlier implant placement. Conclusion: Platelet Rich-Fibrin is widely accepted for use in periodontal surgery and dentistry due to its minimally invasive nature and low risk of adverse effects, with positive results in tissue regeneration. There is evidence that PRF leads to improved and faster healing, as well as cost-effective regenerative procedures compared to other treatments.

Evaluation of Dimensional Changes and Ridge Contour Around Ovate Pontics Inserted Immediately After Extraction with Alveolar Ridge Preservation in the Esthetic Zone.

Alveolar ridge preservation (ARP) is indicated to attenuate anatomic and physiologic changes following tooth extraction. A properly contoured ovate pontic placed immediately into an extraction socket may be adequate to maintain alveolar ridge architecture for improved esthetic results. This prospective clinical study evaluated the ability of immediately placed ovate pontics in conjunction with ARP to attenuate postextraction tissue dimensional changes in the esthetic zone and maintain alveolar ridge contour. Ten patients (11 sites) completed the study. All subjects received a combination of socket grafting with allogeneic particulate graft material and socket sealing with an ovate pontic provisional restoration. A set of clinical linear and volumetric outcomes were assessed after a 6-month healing period. At 6 months postoperative, the linear measurements for the mean ridge dimensional loss were 0.9 ± 0.6 mm (range: 0.2 to 1.8 mm) in height and 1.4 ± 0.6 mm (range: 0.1 to 2.4 mm) in width. The mean volumetric tissue loss observed was 24.4 ± 15.4 mm3 (range: 2.6 to 50.1 mm3) at 3 months postoperative and 32.2 ± 14.2 mm3 (range: 3.8 to 50.5 mm3) at 6 months postoperative. Resorption pattern assessment showed the overall cervical area to have less resorption than the apical areas at 6 months postoperative, with the least amount of resorption in the midbuccal cervical section. When compared to the data of a previous pilot study, no statistically significant difference was seen between the dimensional losses when using ovate pontics with and without ARP. This may be evidence that the use of an ovate pontic provisional restoration immediately after extraction effectively attenuates postextraction dimensional changes.

Digital guides to facilitate retained root removal and simultaneous implant placement

The aim of this study was to report the use of digital guides to locate impacted residual roots (IRR) (location guide) and to simultaneously insert dental implants (surgical guide). This case series included five patients. The IRR was first removed through a lateral window approach using the digital location guide, then the implant was placed simultaneously with the implant surgical guide. Definitive restorations were completed after a 6-month healing period. An average of 13.0 ± 3.1 minutes was required to locate the IRR. The implant stability quotient (ISQ) was obtained during surgery and before digital coping using a non-invasive resonance frequency measurement. The average ISQ during surgery for the five dental implants was 60.2 ± 6.3, and the value increased to 66.6 ± 4.8 before final restoration. The average deviations at the implant neck and root apex were 0.48 ± 0.25 mm and 0.74 ± 0.46 mm, respectively. The average angular deviation was 3.5 ± 1.4°. Bone resorption at the implant neck was a mean 0.072 ± 0.041 mm before final restoration. All implants functioned well at 1 year after final restoration. The application of surgical guides in the extraction of IRR enabled crestal bone preservation and simultaneous implant placement.

In vivo efficacy of 3D-printed elastin-gelatin-hyaluronic acid scaffolds for regeneration of nasal septal cartilage defects.

Nasal septal cartilage perforations occur due to the different pathologies. Limited healing ability of cartilage results in remaining defects and further complications. This study sought to assess the efficacy of elastin-gelatin-hyaluronic acid (EGH) scaffolds for regeneration of nasal septal cartilage defects in rabbits. Defects (4 × 7 mm) were created in the nasal septal cartilage of 24 New Zealand rabbits. They were randomly divided into four groups: Group 1 was the control group with no further intervention, Group 2 received EGH scaffolds implanted in the defects, Group 3 received EGH scaffolds seeded with autologous auricular chondrocytes implanted in the defects, and Group 4 received EGH scaffolds seeded with homologous auricular chondrocytes implanted in the defects. After a 4-month healing period, computed tomography (CT) and magnetic resonance imaging (MRI) scans were obtained from the nasal septal cartilage, followed by histological evaluations of new tissue formation. Maximum regeneration occurred in Group 2, according to CT, and Group 3, according to both T1 and T2 images with 7.68 ± 1.36, 5.44 ± 2.41, and 8.72 ± 3.02 mm2 defect area respectively after healing. The difference in the defect size was statistically significant after healing between the experimental groups. Group 3 showed significantly greater regeneration according to CT scans and T1 and T2 images. The neocartilage formed over the underlying old cartilage with no distinct margin in histological evaluation. The EGH scaffolds have the capability of regeneration of nasal cartilage defects and are able to integrate with the existing cartilage; yet, they present the best results when pre-seeded with autologous chondrocytes.

Responses of Sinus Membrane and Antral Pseudocyst Following Lateral Window Sinus Augmentation with Bone Grafting: A Retrospective Study.

To investigate the influence of lateral window sinus augmentation on sinus physiology, including sinus membrane thickness and the outcome of antral pseudocysts. This retrospective study was performed by reviewing all lateral window sinus augmentation procedures, which were done between the years 2013 and 2015. Each enrolled patient had CBCT images preoperatively (T0), immediately postoperatively (T1), and 6 months postoperatively (T2). The sinus membrane thickness, pseudocyst dimensions, and intraoperative perforation were evaluated. Patient-related factors such as age and sex that could influence the mucosal properties were also analyzed. Based on established inclusion criteria, 306 patients with 320 sinuses were included in this study. The overall mean thickness of the sinus membrane (T0) was 1.30 ± 1.08 mm, and membrane thickening (> 2 mm) was observed in 22.19% of the sinuses. Preexisting pseudocysts were identified in 24 sinuses (7.50%), most of which remained unchanged or disappeared after 6 months. The intraoperative membrane perforation rate was lowest (1.96%) when the membrane thickness was 1.0 to 1.5 mm, and the perforation rate was increased in patients with thickened (> 2 mm) or thinned (≤ 1 mm) membrane. Membranes swelled immediately after operation (T1 vs T0, P < .01) and gradually recovered at 6 months. No significant change in membrane thickness was shown after the sinus augmentation procedure in the perforation group and pseudocyst group. The mean thickness of the sinus membrane at T0 and T1 was significantly higher for male subjects (P < .01). Lateral window sinus augmentation has little or no impact on sinus membrane thickness and antral pseudocysts after a 6-month healing period, except for a transient mild membrane swelling. Thickened and thinned membrane were risk factors for intraoperative perforation. Small-sized perforation and pseudocysts might not contraindicate sinus augmentation from the standpoint of the surgical impact on the sinus membrane.

Clinical Outcomes of Alveolar Ridge Augmentation with In Situ Autogenous Block Bone: A Retrospective Review.

To present clinical outcomes of alveolar ridge augmentation using in situ autogenous block bone and to compare the outcomes with previous studies. The medical records of patients with a severe horizontal bone defect in a partially edentulous alveolar ridge (width < 3.5 mm), who received bone augmentation using in situ autogenous block bone, were retrospectively reviewed. After a 6-month or longer healing period, the augmentation effect was examined before implant placement. Cone beam computed tomography (CBCT) was performed before and after surgeries. The alveolar width of the bone grafts was measured on the CBCT images. A total of 16 patients (22 grafts) were included. Graft exposure was seen in three grafts, which were classified as failed cases. The augmentation volume at implant placement in the failed cases was significantly lower than that of the successful cases. There were no significant differences in augmentation between anterior maxillary and mandibular implant sites. Autogenous bone grafting using in situ block bone is an effective and reliable approach for horizontal bone augmentation in the mandible and anterior maxilla that eliminates second donor site morbidity. Complete release of the buccal flap and tension-free suture is the key to avoiding wound dehiscence and ensuring the effectiveness of bone augmentation.

The role of cortical perforations in allogeneic block grafting for lateral augmentation in maxilla: A randomized clinical trial.

The need of decortication on the recipient site remains unclear for bone regeneration. To our knowledge, there are no human clinical trials that studied the influence of decortication on cancellous allogeneic block grafting. The aim of the present study is to evaluate the influence of perforating the cortex of the recipient site on cancellous allogeneic block graft integration and revascularization in the maxilla. Twenty-six patients referred for lateral bone augmentation were included in this clinical trial. Patients received freeze-dried bone allograft cancellous blocks obtained from the iliac crest; cortical perforations of the recipient bed were performed in the test group while in the control group it was left intact. After a 4-month healing period another surgery was performed to place dental implants, and a bone biopsy was collected using a trephine. All samples underwent micro-CT scans, and were processed for histomorphometric and immunohistochemical analysis. Implant survival comparisons were made using a repeated measures analysis of variance (ANOVA) while all other variables were compared using the analysis of covariance (ANCOVA). One hundred and nineteen implants were placed into 110 augmented sites. One hundred percent implant survival rate was reported during 24 months follow-up period. No differences were reported in bleeding on probing at 1 (5.6 vs 9%) and 2 years (13.2 vs 12.1%), probing pocket depth at 1 (3.4 ± 0.95 vs 3.6 ± 1.12 mm) and 2 years (3.8 ± 1.02 vs 4.1 ± 1.46 mm), and marginal bone loss at 1 (0.2 ± 0.52 vs 0.3 ± 0.57 mm) and 2 years (0.6 ± 0.91 vs 0.5 ± 0.87 mm). No statistically significant differences were found in the micro-CT and histomorphometric analysis in terms of newly formed bone (25.7 ± 11.2% vs 22.3 ± 9.7%), soft tissue (33.0 ± 14.7% vs 36.5 ± 15.7%), remnant allograft (39.3 ± 20.4% vs 41.2 ± 22.7%), and bone mineralization (57.2 ± 10.6% vs 53.8 ± 8.7%). Perforating the cortex of the recipient site had no significant effect on angiogenesis as shown by immunohistochemical analysis of CD34 positive blood vessels (39.21 ± 10.53/mm2 vs 34.16 ± 12.67/mm2 ). Cancellous allogeneic bone block grafts are a clinically acceptable alternative for horizontal bone augmentation. Cortical perforations of the recipient site in the maxilla did not improve angiogenesis nor bone formation within the block graft.

Prosthetically Driven Alveolar Reconstructions: A Retrospective Study.

This study aims to evaluate the post-extraction alveolar bone reconstruction amongst 12 patients exhibiting loss of buccal bone plate in a tooth of the anterior region of the maxilla using the prosthetically-driven alveolar reconstruction technique (PDAR). In PDAR, a partial fixed provisional prosthesis (PFPP [conventional or adhesive]) with a specially designed pontic maintains the clot in a mechanically stable position during alveolar regeneration. Moreover, the pontic design, in hourglass shape and located in the subgingival area, also prevents gingival margins from collapsing. Gingival recession was evaluated through the 6-month healing period. Cone beam computed tomography (CBCT) was performed 1 month before and 8 months after PDAR treatment. For the primary outcome, in the panoramic imaging, the central area of bone defect in each tooth was selected for linear measurements. Measurements of the vertical buccal bone gain and the gain in thickness in the alveolar bone crest were obtained 8 months after PDAR. Descriptive statistics and intraclass correlation coefficient analysis were conducted. After treatment, all patients showed bone formation (a mean vertical gain of 7.1±3.7 mm, associated with a horizontal mean gain of 4.5±1.4 mm in the alveolar bone crest). The intraclass correlation coefficient for the measurements performed using CBCT was 0.999. No gingival recession, greater than 1 mm, was observed. Lower-morbidity procedures without the use of biomaterials may be a useful in post-extraction alveolar ridge regeneration and/or preservation. PDAR promoted alveolar bone formation without flaps, grafts and membranes.

Sinus floor augmentation using mixture of mineralized cortical bone and cancellous bone allografts: Radiographic and histomorphometric evaluation

Background/purposeDue to the pneumatization of the maxillary sinus, the sinus floor augmentation is often performed to implant placement in the maxillary posterior region. The aim was to perform radiographic and histomorphometric evaluation after placement of mixed allografts (cortical freeze-dried bone allograft [FDBA] 50%:cancellous FDBA 50%) during sinus floor augmentation. Materials and methodsIn 37 patients, anorganic bovine bone (ABB, sites = 16), mineralized cancellous bone allograft (MCBA, sites = 15), and mixed allografts (Mixed AG, sites = 20) were placed during sinus floor elevation via the lateral approach (LSFE), at total 51 sites with residual alveolar bone height (RBH) < 5 mm. Cone-beam computed tomography images were obtained before LSFE (T0), after surgery (T1), and 6 months after surgery (T2) for radiographic analysis. After a 6-month healing period, core biopsies were harvested and histomorphometric analysis was performed. ResultsThe mean augmented bone height (ABH) of ABB, MCBA, and mixed AG groups after surgery was similar (13.86 ± 4.19 mm, 13.99 ± 4.07 mm, and 14.20 ± 3.12 mm, respectively; P > 0.05). The mean ABH of ABB, MCBA, and mixed AG groups after 6 months was similar (13.72 ± 4.55 mm, 11.83 ± 3.31 mm, and 12.53 ± 2.97 mm, respectively; P > 0.05). In the ABB, MCBA, and mixed AG groups, the proportion of newly formed bone (NB) was similar (36.13 ± 10.01%, 39.26 ± 10.72%, and 31.27 ± 18.31%, respectively; P > 0.05). ConclusionThis result demonstrated that mixed AG led to sufficient bone augmentation and histologically comparable NB formation as compared to ABB and MCBA for sinus floor augmentation.

Effect of alveolar ridge preservation interventions following tooth extraction: A systematic review and meta-analysis.

The aim of this systematic review was to critically analyse the available evidence on the effect of different modalities of alveolar ridge preservation (ARP) as compared to tooth extraction alone in function of relevant clinical, radiographic and patient-centred outcomes. A comprehensive search aimed at identifying pertinent literature for the purpose of this review was conducted by two independent examiners. Only randomized clinical trials (RCTs) that met the eligibility criteria were selected. Relevant data from these RCTs were collated into evidence tables. Endpoints of interest included clinical, radiographic and patient-reported outcome measures (PROMs). Interventions reported in the selected studies were clustered into ARP treatment modalities. All these different ARP modalities were compared to the control therapy (i.e. spontaneous socket healing) in each individual study after a 3- to 6-month healing period. Random-effects meta-analyses were conducted if at least two studies within the same ARP treatment modality reported on the same outcome of interest. A combined database, grey literature and hand search identified 3,003 records, of which 1,789 were screened after removal of duplicates. Following the application of the eligibility criteria, 25 articles for a total of 22 RCTs were included in the final selection, from which nine different ARP treatment modalities were identified: (a) bovine bone particles (BBP)+socket sealing (SS), (b) construct made of 90% bovine bone granules and 10% porcine collagen (BBG/PC)+SS, (c) cortico-cancellous porcine bone particles (CPBP)+SS, (d) allograft particles (AG)+SS, (e) alloplastic material (AP) with or without SS, (f) autologous blood-derived products (ABDP), (g) cell therapy (CTh), (h) recombinant morphogenic protein-2 (rhBMP-2) and (i) SS alone. Quantitative analyses for different ARP modalities, all of which involved socket grafting with a bone substitute, were feasible for a subset of clinical and radiographic outcomes. The results of a pooled quantitative analysis revealed that ARP via socket grafting (ARP-SG), as compared to tooth extraction alone, prevents horizontal (M=1.99mm; 95% CI 1.54-2.44; p<0.00001), vertical mid-buccal (M=1.72mm; 95% CI 0.96-2.48; p<0.00001) and vertical mid-lingual (M=1.16mm; 95% CI 0.81-1.52; p<0.00001) bone resorption. Whether there is a superior ARP or SS approach could not be determined on the basis of the selected evidence. However, the application of particulate xenogenic or allogenic materials covered with an absorbable collagen membrane or a rapidly absorbable collagen sponge was associated with the most favourable outcomes in terms of horizontal ridge preservation. A specific quantitative analysis showed that sites presenting a buccal bone thickness >1.0mm exhibited more favourable ridge preservation outcomes (difference between ARP [AG+SS] and control=3.2mm), as compared to sites with a thinner buccal wall (difference between ARP [AG+SS] and control=1.29mm). The effect of other local and systemic factors could not be assessed as part of the quantitative analyses. PROMs were comparable between the experimental and the control group in two studies involving the use of ABDP. The effect of other ARP modalities on PROMs could not be investigated, as these outcomes were not reported in any other clinical trial included in this study. Alveolar ridge preservation is an effective therapy to attenuate the dimensional reduction of the alveolar ridge that normally takes place after tooth extraction.

Changes in alveolar process dimensions following extraction of molars with advanced periodontal disease: A clinical pilot study.

To use cone beam computed tomography (CBCT) to assess the alterations of socket dimensions after a 6-month healing period following molar extraction. Seventeen molars were extracted due to advanced periodontitis. CBCT scans were taken immediately after extraction and once more 6months later. Superimposition of CBCT images was used to measure the following: horizontal changes at extraction sites at three corono-apical levels (-1, -3, and -5mm) below the bone crest, three mesio-distal levels (mesial, central, and distal), vertical changes at nine regions of the alveolar crest, and alveolar bone volume. The width of the central crests at -1mm decreased by 0.59 and 0.72mm in the buccal and 0.27 and 0.02mm in the lingual, in the maxilla and mandible, respectively. No statistically significant decreases in the ridge height were observed except in the disto-palatal region with a 1.11mm decrease in the maxilla (p<0.05). Heights of the buccal and lingual bone plates decreased significantly and ranged from 0.56 to 1.38mm in the mandible after 6months of healing (p<0.05). Overall, ridge height changes were not significantly different between the maxilla and mandible (p>0.05) and no significant volumetric bone loss occurred in either maxillary or mandibular sockets after 6months of healing. Socket dimensions of molars with advanced periodontal disease showed a significant increase at the middle-central portion, although there were no significant changes of horizontal width 6months following the procedures.

Comparative Histological and Histomorphometric Results of Six Biomaterials Used in Two-Stage Maxillary Sinus Augmentation Model after 6-Month Healing.

Objectives To evaluate the performances of six different bone substitute materials used as graft in maxillary sinus augmentation by means of histological and histomorphometric analysis of bone biopsies retrieved from human subjects after a 6-month healing period. Materials and Methods Six consecutive patients (3 males, 3 females, aged 50-72 years), healthy, nonsmokers, and with good oral hygiene, presenting edentulous posterior maxilla with a residual bone crest measuring ≤ 4 mm in vertical height and 3 to 5 mm in horizontal thickness at radiographic examination, were selected to receive sinus augmentation and delayed implant placement. Under randomized conditions, sinus augmentation procedures were carried out using mineralized solvent-dehydrated bone allograft (MCBA), freeze-dried mineralized bone allograft (FDBA), anorganic bovine bone (ABB), equine-derived bone (EB), synthetic micro-macroporous biphasic calcium-phosphate block consisting of 70% beta-tricalcium phosphate and 30% hydroxyapatite (HA-β-TCP 30/70), or bioapatite-collagen (BC). After 6 months, bone core biopsies were retrieved and 13 implants were placed. Bone samples were processed for histological and histomorphometric analysis. CT scans were taken before and after surgery. After 4 months of healing, patients were restored with a provisional fixed acrylic resin prosthesis, as well as after further 2-4 months with a definitive cemented zirconia or porcelain-fused-to-metal crowns. Results There were no postoperative complications or implant failures. The histological examination showed that all biomaterials were in close contact with newly formed bone, surrounding the graft granules with a bridge-like network. No signs of acute inflammation were observed. The histomorphometry revealed 20.1% newly formed bone for MCBA, 32.1% for FDBA, 16.1% for ABB, 22.8% for EB, 20.3% for HA-β-TCP 30/70, and 21.4% for BC. Conclusions Within the limitations of the present investigation, all the six tested biomaterials showed good biocompatibility and osteoconductive properties when used in sinus augmentation procedures, although the FDBA seemed to have a better histomorphometric result in terms of newly formed bone and residual graft material. This trial is registered with ClinicalTrials.gov Identifier (Registration Number): NCT03496688.

Histologic and Radiographic Analysis of Nonhealing Extraction Sockets Treated with Bio-Oss Collagen After a 4-Month Healing Period: A Prospective Descriptive Study in Humans.

Healing of extraction sockets may sometimes result in formation of fibrous tissue instead of bone, even after 4 months, an occurrence that may hinder implant placement. The aim of this preliminary observational study was to histologically evaluate quality and amount of bone regeneration after treating nonhealing sockets with a bovine-derived xenograft enriched with porcine collagen (Bio-Oss Collagen, Geistlich) without barrier membranes. Biopsy specimens were collected during implant placement, 4 months after grafting. A total of 10 cases were treated and evaluated. In all cases, correct implant placement was possible and no implant failure occurred up to 6 months after loading. The histologic analysis demonstrated new bone formation in all specimens. The percentage of newly formed bone was 29.1% (SD 20.71%; range 5% to 48%). Xenograft particles in direct contact with newly formed bone were visible, and mature lamellar bone was observed in 8 cases.