Lateral Ridge Augmentation with Guided Bone Regeneration Using Particulate Bone Substitutes and Injectable Platelet-Rich Fibrin in a Digital Workflow: 6 Month Results of a Prospective Cohort Study Based on Cone-Beam Computed Tomography Data

This study aimed to test whether or not a digital workflow for GBR with particulate bone substitutes and injectable platelet-rich fibrin improved the thickness of the hard tissue compared to the conventional workflow. 26 patients in need of lateral bone augmentation were enrolled. GBR with particulate bone substitutes and injectable platelet-rich fibrin was performed in all patients. Patients were divided into two groups: control (conventional workflow; n = 14) and test (digital workflow; n = 12). CBCT scans were performed before surgery, immediately after wound closure, and 6 months post-surgery, and the labial thickness of the hard tissue (LT) was assessed at 0–5 mm apical to the implant shoulder (LT₀–LT₅) at each time point. A total of 26 patients were included in this study. After wound closure, the test group showed significantly greater thickness in LT₀–LT₂ than the control group (LT₀: test: 4.31 ± 0.73 mm, control: 2.99 ± 1.02 mm; LT₁: test: 4.55 ± 0.69 mm, control: 3.60 ± 0.96 mm; LT₂: test: 4.76 ± 0.54 mm, control: 4.05 ± 1.01 mm; p < 0.05). At 6 months, significant differences in LT₀–LT₁ were detected between the groups (LT₀: test: 1.88 ± 0.57 mm, control: 1.08 ± 0.60 mm; LT₁: test: 2.36 ± 0.66 mm, control: 1.69 ± 0.58 mm; p < 0.05). Within the limitations of this study, the use of digital workflow in GBR with particulate bone substitutes and i-PRF exerted a positive effect on the labial thickness of hard tissue in the coronal portion of the implant after wound closure and at 6 months.

Implant Site Guided Bone Regeneration and Pontic Site Ridge Preservation: A Case Report

Guided bone regeneration (GBR) is a therapeutic modality to achieve bone regeneration with the use of barrier membranes. The use of deproteinized bovine bone material (DBBM) for ridge preservation allows the preservation of the edentulous ridge dimensions. Here, we present a case of horizontal GBR using DBBM and a resorbable membrane, with simultaneous implant placement. Simultaneously, ridge preservation of the pontic area, using DBBM within a "socket seal" procedure was performed. Two implants were places at sites 23 and 26 to support a fixed partial denture (FPD). The mesial implant showed exposed buccal threads, which were then covered with autogenous bone particles and small size granules of DBBM. The collagen membrane was stabilized with periosteal mattress suture. Six months postoperatively, CBCT images revealed a stable buccal bone layer at the implant site, indicating a successful GBR procedure. At this point in time, tooth 24 was atraumatically extracted. A ridge preservation was done utilizing DBBM, and a soft tissue graft form the tuber. A ceramic-metal FPD with excellent "white aesthetics" and a harmonic transition zone to the soft tissue was fabricated. At 3 years follow up, the peri-implant bone levels were stable, and the clinical outcomes were excellent. It is concluded that a GBR procedure, utilizing DBBM and a collagen barrier membrane with simultaneous implant placement, as well as ridge preservation using DBBM, are predictable therapeutic methods. However, gentle manipulation of the soft tissues, and wound stability, with tension-free passive closure of the wound margins are prerequisites for a long-term clinical success.

Contact Angle and Cell Adhesion of Micro/Nano-Structured Poly(lactic-co-glycolic acid) Membranes for Dental Regenerative Therapy

Biodegradable membranes are used in regenerative dentistry for guided tissue regeneration (GTR) and guided bone regeneration (GBR). In this study, patterned poly(lactic-co-glycolic acid) (PLGA) membranes with groove, pillar, and hole structures were successfully fabricated by thermal nanoimprinting. Their surfaces were evaluated for topography by scanning electron microscopy and laser microscopy, for hydrophobicity/hydrophilicity by contact angle analysis, and for MC3T3-E1 cell adhesion. The sizes of the patterns on the surfaces of the membranes were 0.5, 1.0, and 2.0 μm, respectively, with the height/depth being 1.0 μm. The pillared and holed PLGA membranes were significantly more hydrophobic than the non-patterned PLGA membranes (p < 0.05). However, the 0.5 μm- and 1.0 μm-grooved PLGA membranes were significantly more hydrophilic than the non-patterned PLGA membranes (p < 0.05). The 0.5 μm-grooved, pillared, and holed membranes exhibited significantly superior adhesion to the MC3T3-E1 cells than the non-patterned PLGA (p < 0.05). These results suggest that patterned PLGA membranes can be clinically used for GTR and GBR in the dental regeneration field.

Influence of soft tissue augmentation procedures around dental implants on marginal bone level changes-A systematic review

OBJECTIVES

This systematic review assessed the influence of soft tissue augmentation procedures on marginal bone level changes in partial or fully edentulous patients.

MATERIAL AND METHODS

We identified three relevant PICO questions related to soft tissue augmentation procedures and conducted a systematic search of four major electronic databases for clinical studies in systemically healthy patients receiving at least one dental implant and a minimum follow-up of one year after implant placement. The primary outcome was mean difference in marginal bone levels, and secondary outcomes were clinical and patient-related outcomes such as thickness of peri-implant mucosa, bleeding indices, and Pink Esthetic Score.

RESULTS

We identified 20 publications reporting on 16 relevant comparisons. Studies varied considerably and thus only two meta-analyses could be performed. This systematic review showed that: Soft tissue augmentation either for augmentation of keratinized mucosa or soft tissue volume inconsistently had an effect on marginal bone level changes when compared to no soft tissue augmentation, but consistently improved secondary outcomes. The combination soft and hard tissue augmentation showed no statistically significant difference in terms of marginal bone level changes when compared to hard tissue augmentation alone, but resulted in less marginal soft tissue recession as shown by a meta-analysis. Soft or hard tissue augmentation performed as contour augmentations resulted in comparable marginal bone level changes.

CONCLUSIONS

Peri-implant soft and hard tissues seem to have a bidirectional relationship: "Bone stands hard, but soft tissue is the guard".

Vertical Ridge Augmentation With a Honeycomb Structure Titanium Membrane: A Technical Note for a 3-Dimensional Curvature Bending Method

Guided bone regeneration is the most commonly used technique for vertical ridge augmentation (VRA), and it is popular because it is less invasive and highly formative. Since the augmented site is exposed to external pressure, it is preferable to support the membrane using a framework to maintain the shape of the VRA. Recently, a titanium framework-reinforced ultrafine titanium membrane was developed by laser processing technology. The technique allows microperforations to be made (φ20 μm) into a titanium membrane, which is expected to prevent fibrous tissue ingrowth from outside the membrane. In addition, significant bone regeneration was confirmed on ridge defects in previous animal studies. However, the membrane tends to crumple during the bending process, because it is very thin (20 nμm); thus, the bending procedures are technically sensitive. Since this titanium honeycomb membrane was first approved for clinical use in Japan, no international clinical reports have been published. The purpose of this case report is to describe a technical note for a 3-dimensional curvature bending method in VRA using the newly developed honeycomb structure titanium membrane.

Peri-implant soft tissue contour after stepwise replacement of missing and ankylotic central maxillary incisors in young adult: A clinical case report

Replantation and retention of ankylosed tooth after pubertal growth spurt enables stepwise replacement of both central incisors with implants. Partial extraction contributes to natural gingival contour.

Influence of Different Incision Designs on Flap Extension: A Cadaveric Animal Model

It is well known that wound dehiscence is one of the most frequent complications in guided bone regeneration. The main cause of this complication may be a lack of tension-free and primary wound closure. The aim of this study was to evaluate and compare the effect of periosteal releasing incisions (PRI) on the extension of 3 different flap designs: envelope, triangular, and trapezoidal. Twelve pig mandibles were used to quantify extension of the flap designs. The mandibles were equally and randomly distributed into the 3 flap groups. Each mandible was divided into 2 sides: 1 was subjected to a PRI and the other not. The flap was pulled with a force of 1.08 N, and the extension was recorded. The subgroups without PRI showed an average extension of 5.14 mm with no statistically significant differences among them (P = .165). The PRI provided an average extension of 7.37 mm with statistically significant differences among the subgroups (P < .001). The releasing incisions significantly increased flap extension in each flap design. The increase in extension of the trapezoidal flap with PRI was significantly greater than in the other subgroups. In cases where primary closure is required, surgeons should consider performing trapezoidal flaps with PRI in order to reduce tension.

Clinical and radiographical performance of implants placed with simultaneous guided bone regeneration using resorbable and nonresorbable membranes after 22-24 years, a prospective, controlled clinical trial

Aim

The aim was to evaluate the performance of implants placed with simultaneous guided bone regeneration (GBR) using resorbable or nonresorbable membranes compared to implants placed in pristine bone without bone regeneration after an observation period of 22–24 years.

Material and Methods

The patient cohort of this clinical trial was treated from 1994 to 1996. Dehiscence defects were treated with GBR by either using resorbable collagen membranes (BG) or nonresorbable ePTFE membranes (GT). Implants placed in pristine bone served as a control (CT). Clinical parameters, marginal bone levels, and technical outcomes were evaluated following restoration placement and at the present follow‐up. A 3D radiographic analysis was conducted in order to assess buccal and oral bone dimensions. Implant survival was assessed with Kaplan–Meier analysis and a frailty model (level of significance 5%).

Results

Out of the originally 72 patients (mean age 75.4 ± 15.70 years) with 265 implants, 39 patients with 147 implants were included in the study after a median period of 23.5 years. Implant survival was 89.3% in group BG (n = 100), 90.2% in group GT (n = 37), and 93.8% in group CT (n = 105), without significant differences (Frailty proportional hazard model p = .79). Smoking had a negative effect on survival (p = .0122). Mean vertical marginal bone levels were −2.3 ± 1.4 mm (BG, n = 59), −3.0 ± 1.5 mm (GT, n = 21), and −2.3 ± 1.6 mm (CT, n = 52). The vertical buccal bone levels were −3.0 ± 1.9 mm (BG, n = 57), −3.5 ± 2.2 mm (GT, n = 21), and −2.6 ± 1.8 mm (CT, n = 49), without significant differences.

Conclusion

Implant placement with GBR procedures provides treatment outcomes with favorable implant survival rates (89.3%–93.8%) after 23.5 years. Smoking, however, affected implant survival negatively.

Primary bone augmentation leads to equally stable marginal tissue conditions comparing the use of xenograft blocks infused with BMP-2 and autogenous bone blocks: A 3D analysis after 3 years

Objectives

To test whether or not primary bone augmentation using xenograft blocks infused with BMP‐2 or autogenous bone blocks lead to similar results regarding the implant survival and 3D marginal soft tissue contours.

Methods

Twenty‐four patients with an insufficient ridge width for implant placement in need of primary augmentation were randomly assigned to either a block of deproteinized bovine bone mineral infused with rhBMP‐2 (BMP) or an intraorally harvested block of autogenous bone (ABB). At 4 months, 1–4 dental implants were placed in the regenerated area. After crown insertion and at 3 years, peri‐implant tissue parameters, two‐ and three‐dimensional radiographic parameters, and soft tissue contour changes were evaluated. Explorative mixed model analyses were performed. The level of significance was set at 5%.

Results

At the 3‐year follow‐up, 23 patients with 40 implants were evaluated. The implant survival rate was 100% in both groups. At baseline, the marginal hard tissue levels amounted to −0.4 ± 0.8 mm (mean ± standard deviation) in the BMP group and −0.7 ± 1.0 mm in the ABB group. At 3 years, these values were −0.2 ± 0.4 mm (BMP) and −0.6 ± 1.0 mm (ABB). At baseline, the thickness of the buccal hard tissue at the level of the implant shoulder measured 1.1 ± 1.1 mm (BMP) and 1.4 ± 1.0 mm (ABB). At 3 years, it measured 0.9 ± 0.9 mm (BMP) and 0.7 ± 0.6 mm (ABB).

Conclusions

The present study demonstrated excellent implant survival rates and stable marginal hard tissue levels in both augmentation groups, 3 years after crown insertion. In addition, the clinical stability of soft and hard tissues was demonstrated in both groups.

Implants Survival Rate in Regenerated Sites with Innovative Graft Biomaterials: 1 Year Follow-Up

In thirteen different dental clinics in Singapore, Spain, Czech Republic and Italy, 504 patients were selected, and 483 dental implants were placed in maxillary sites after alveolar socket preservation (ASP) procedures with an autologous demineralized tooth extracted as graft material from an innovative Tooth Transformer device was obtained. All procedures used were reported in n°638 Ethical Committee surgical protocol of University of Chieti and approved. After 4 months, at dental implant placing, bone biopsies were performed to evaluate the histologic outcomes, and 12 months after implant loading, global implant survival rate, failure percentage and peri-implant bone loss were detected. After ASP, only 27 post-operative complications were observed and after 4 months, bone biopsy histomorphometric analysis showed a high percentage of bone volume (BV) 43.58 (±12.09), and vital new bone (NB) 32.38 (±17.15) with an absence of inflammation or necrosis areas. Twelve months after loading, only 10 dental implants failed (2.3%), with a 98.2% overall implant survival rate, nine cases showed mucositis (1.8%) and eight showed peri-implantitis (1.6%). At mesial sites, 0.43 mm (±0.83) of bone loss around the implants was detected and 0.23 mm (±0.38) at the distal sites with an average value of 0.37 mm (±0.68) (p > 0.568). Several studies with a longer follow-up will be necessary to confirm the preliminary data observed. However, clinical results seem to suggest that the post-extraction socket preservation procedure using innovative demineralized autologous tooth-derived biomaterial may be a predictable procedure to produce new vital bone able to support dental implant rehabilitation of maxilla edentulous sites.

Guided Bone Regeneration with Concentrated Growth Factor Enriched Bone Graft Matrix (Sticky Bone) vs. Bone-Shell Technique in Horizontal Ridge Augmentation: A Retrospective Study

Background: The purpose of this study was to compare clinical results of two different horizontal ridge augmentation techniques: guided bone regeneration with sticky bone (SB) and the bone-shell technique (BS). Methods: Records of patients who underwent horizontal ridge augmentation with SB (test) and BS (control) were screened for inclusion. Pre-operative and 6-month post-operative ridge widths were measured on cone beam computer tomography (CBCT) and compared. Post-operative complications and implant survival rate were recorded. Results: Eighty consecutive patients were included in the present study. Post-operative complications (flap dehiscence, and graft infection) occurred in ten patients, who dropped out from the study (12.5% complication rate). Stepwise multivariate logistic regression analysis showed a significant inverse correlation between the occurrence of post-operative complications and ridge width (p = 0.025). Seventy patients (35 test; 35 control) with a total of 127 implants were included in the final analysis. Mean ridge width gain was 3.7 ± 1.2 mm in the test and 3.7 ± 1.1 mm in the control group, with no significant difference between the two groups. No implant failure was recorded, with a mean follow-up of 42.7 ± 16.0 months after functional loading. Conclusions: SB and BS showed comparable clinical outcomes in horizontal ridge augmentation, resulting in sufficient crestal width increase to allow implant placement in an adequate bone envelope.

Prosthodontic Rehabilitation of a Patient with Hypophosphatasia Using Dental Implants: A Case Report with Seven Years Follow-Up

Hypophosphatasia is a rare metabolic inherited dento-osseous disorder. Although there is some available literature on various dental characteristics of hypophosphatasia patients, few reports focus on the effects of hypophosphatasia on the permanent dentition and prosthodontic rehabilitation, particularly in relation to the use of dental implants. This paper reports a case with hypophosphatasia and prosthodontic rehabilitation using dental implants with 7-year follow-up.

Bone Graft and Intraosseous Anchorage of Dental Implants for Reconstruction of the Residual Alveolar Ridge

Background:

Bone grafting aims at better dental implant osseointegration and preserves the remaining alveolar bone in the socket. The success of various bone grafting materials plays a vital role in assessing future implant function.

Aims and Objectives:

The present clinical trial was aimed at evaluating the results of guided bone regeneration (GBR) with and without the bioresorbable membrane in the dental implant placement.

Materials and Methods:

The 20 patients were divided into two groups (n = 10). First was Group I- GBR with bioresorbable collagen membrane (BioGide™) and second was Group II- GBR without membrane. Bone gain and bone levels were analyzed for both groups. All the collected data were analyzed statistically.

Results:

For Group I, bone levels at baseline were nonsignificant (P = 0.2188) Similarly, nonsignificant values were seen in both groups at 3 months with bone level values of 0.25 ± 0.17 and 0.38 ± 0.24 for Group I and Group II, respectively. Changes in the bone levels were found to be 2.45 ± 0.349 and 2.58 ± 0.304 from Group I and II, respectively, inferring the nonsignificant difference with P value of 0.3723. The percentage of bone gain for intergroup at the end of 3 months was 89.15% ±0.678 for Group I and 88.68% ± 0.503%; these values were statistically nonsignificant (P = 0.982).

Conclusion:

Nonsignificant difference was observed between the two groups with and without membrane in terms of changes in bone level, percentage of bone gain, and bone defect reduction. This study concludes that the use of bone grafts significantly improves residual alveolar ridge irrespective of membrane used.

Osseointegration of Dental Implants in Ridges with Insufficient Bones using Different Membranes for Guided Bone Regeneration

Background:

The use of membrane with the guided bone regeneration (GBR) has been a controversial aspect of the implant placement, which helps achieve the primary graft stabilization and inhibit early graft loss.

Objectives:

The present clinical trial was aimed to determine the results of GBR with nonresorbable (expanded polytetrafluoroethylene [e-PTFE]) and resorbable (collagen) membrane both clinically and radiographically for 2 years with dental implant placement.

Materials and Methods:

16 subjects having 32 sites for implant placement in a split-mouth pattern were included in the study. The sites for implant was prepared and grafted with the autogenous graft procured from the mandibular ramus area followed by graft coverage with either e-PTFE or collagen membrane. Various radiographic and clinical parameters were assessed for 2 years at an interval of 6 months each. The collected data were recorded for each study subject for all the implant sites and were statistically analyzed.

Results:

The mean values for periodontal probing depth at 6 months, 12 months, 18 months, and 24 months were 2.25 ± 0.17, 2.67 ± 1.84, 2.64 ± 1.21, and 3.01 ± 0.52, respectively, for the e-PTFE group. For the collagen group, the probing depth mean values at 6 months, 12 months, 18 months, and 24 months were 2.30 ± 0.14, 2.59 ± 1.76, 2.62 ± 1.30, and 2.98 ± 0.81, respectively. The corresponding clinical and radiographic parameters at all time intervals were nonsignificant on the intergroup comparison.

Conclusion:

Dental implants placed with simultaneous GBR have an acceptable survival rate at the end of 2 years irrespective of the resorbable or non-resorbable membrane used.

Vestibular socket therapy with immediate implant placement for managing compromised fresh extraction sockets: A prospective single-arm clinical study

PURPOSE

To assess hard and soft tissues regenerated around immediate implants placed in compromised fresh extraction sockets using vestibular socket therapy 2 years postoperatively.

MATERIALS AND METHODS

Twenty-seven compromised fresh extraction sockets were managed using vestibular socket therapy and immediate implant placement. After immediate implant placement, a cortical bone shield was stabilised through a vestibular incision. The socket defect was filled with particulate bone graft. Labial plate thickness and bone height were evaluated 1 and 2 years postoperatively using CBCT. The pink aesthetic score and probing depth were recorded after 6 months, 1 year and 2 years. A Friedman test was used to study changes in the reported outcomes over time, with the level of statistical significance set at P ≤ 0.05.

RESULTS

All implants recorded a 100.0% survival rate. A statistically significant increase in bone height (0.93 mm, P = 0.004) and apical (0.12 mm, P = 0.026), midfacial (1.26 mm, P < 0.001) and crestal (0.86 mm, P < 0.001) bone thickness was observed after 2 years. The changes in pink aesthetic score and probing depth were not significant: the pink aesthetic score was 12.48 ± 1.45 and the mean PD was 2.37 ± 0.79 mm mesially, 2.11 ± 0.70 mm facially, 2.07 ± 1.04 mm distally and 1.00 ± 0.00 mm palatally after 2 years.

CONCLUSION

Combining immediate implant placement with vestibular socket therapy to manage compromised fresh extraction sockets offers promising radiographic, aesthetic and periodontal results while minimising the treatment time and number of surgical procedures required.

Chorion and amnion/chorion membranes in oral and periodontal surgery: A systematic review

The aim of this study was to perform a systematic review on the clinical applications where chorion membrane (CM) and amnion/chorion membrane (ACM) were used for oral tissue regeneration procedures. Selection of articles was carried out by two evaluators in Pubmed and Scopus databases, and Outcomes (PICO) method was used to select the relevant articles. Clinical studies reporting the use of CM or ACM for oral soft and hard tissue regeneration were included. The research involved 21 studies conducted on 375 human patients. Seven clinical applications of CM and ACM in oral and periodontal surgery were identified: gingival recession treatment, intrabony and furcation defect treatment, alveolar ridge preservation, keratinized gum width augmentation around dental implants, maxillary sinus membrane repair, and large bone defect reconstruction. CM and ACM were compared to negative controls (conventional surgeries without membrane) or to the following materials: collagen membranes, dense polytetrafluoroethylene membranes, platelet-rich fibrin membranes, amnion membranes, and to a bone substitute. Several studies support the use of CM and ACM as an efficient alternative to current techniques for periodontal and oral soft tissue regeneration procedures. However, further studies are necessary to increase the level of evidence and especially to demonstrate their role for bone regeneration.

Guided bone regeneration-assisted orthodontic treatment for closing the space of missing central incisors

Long-term missing teeth can lead to alveolar bone loss in the edentulous area. Guided bone regeneration (GBR) is a bone augmentation method. It is widely used in clinical practice and broadens the indications of orthodontic treatment to a certain extent. This article reports a case of an adult patient with edentulous space in the maxillary central incisor, which was successfully closed through orthodontic treatment combined with GBR. This study will provide a re-ference for future clinical work.

Delayed post-extraction implants placed using a modified Summers technique: Preliminary results of a single cohort study

The aim of this retrospective case series was to evaluate the clinical and radiographic outcomes of the patients that underwent implant surgery with a modification of the sinus lift summers protocol. Forty healthy patients in need for oral rehabilitation with dental implants were included in this study. Inclusion criterion was the need for extraction of one compromised tooth due to persistent abscess/ periodontitis/cyst in the atrophic posterior maxilla region. The treatment consisted of two stage surgery for all patients. In the first stage, after tooth extraction, the sockets were preserved with allogenic bone graft and equine collagen membrane. After 4-5 months, 40 implants with a sandblasted surface, were inserted with osseodensification technique and a modification of the Summers sinus lift protocol for fracturing the sinus floor. The implant survival rate was the primary outcome. Intra- and postoperative complications were additional criteria for success. The mean follow-up from implant surgery was 28.0±7.3 (standard deviation) months (range 17.8-43.4 months). One implant was lost before the delivery of the prosthesis. The overall implant survival rate was 97.5%. The overall mean peri-implant marginal bone level change after 6 and 12 months of function was, respectively, 0.26±0.24 mm (95% CI: 0.19, 0.34 mm) and 0.71±0.36 mm (95% CI: 0.60, 0.82 mm). Marginal bone loss was statistically significant at both time frames respect to implant placement, and also the difference between 6 and 12 months was significant (p<0.001 in both cases). No biological nor mechanical complications were recorded throughout the observation period. As a conclusion, the technique presented in this cohort study can be an effective and safe alternative to standard maxillary sinus floor augmentation procedures and immediate implant insertion protocol, especially in cases of periodontitis and infected sites, which can represent a high risk for implant failure in patients with atrophic posterior maxilla.

Effects of platelet-rich fibrin combined with guided bone regeneration in the reconstruction of peri-implantitis bone defect

OBJECTIVE

To investigate the clinical effect of platelet-rich fibrin (PRF) combined with guided bone regeneration (GBR) in the reconstruction of peri-implantitis bone defect.

METHODS

This prospective study included 80 patients with peri-implantitis who underwent implant restoration in the Department of Stomatology in our hospital. The eligible patients were randomly divided into control group and observation group, with 40 cases in each group. Patients in the control group were treated with flap curettage combined with GBR, while those in the observation group received a mixture of PRF and bone powder implanted with GBR and covered with PRF biofilm. The differences of pain 24 hours after surgery, bleeding at 7 days after surgery, and the degree of bone defect between the two groups at 60 days after surgery were compared. At 60 days and 120 days after surgery, separately, the regenerated bone density of patients in the two groups was measured, analyzed and compared. The degree of regenerated bone defect in transverse and longitudinal directions after 60 days was compared between the two reconstruction procedures.

RESULTS

The pain at 24 hours after surgery and the bleeding at 7 days after surgery in the observation group were milder than those in the control group (P<0.001). There was significant difference in the degrees of bone defect at 60 days after surgery (P<0.05). Compared with the control group, the regenerated bone density of the observation group was significantly higher both at 60 days and 120 days after surgery (P<0.001).

CONCLUSION

The combination of PRF and GBR technology has an obvious effect in repairing bone defects in patients with peri-implantitis, and can reduce the pain of patients during the repair process.

Addition of autogenous bone chips to deproteinized bovine bone mineral does not have additional benefit in lateral ridge augmentation-A preclinical in vivo experimental study

OBJECTIVE

To compare the outcome after extensive lateral guided bone regeneration using deproteinized bovine bone mineral (DBBM) with or without autogenous bone chips in a canine model of chronic horizontal alveolar ridge defect.

MATERIALS AND METHODS

The second, third and fourth lower premolars of both sides were extracted, and the buccal bone walls were completely removed in five beagle dogs. After 4 weeks, DBBM particles mixed with autogenous bone chips at a ratio of 1:1 were grafted at one side (DBBM/Auto group), while DBBM particles alone were grafted at the contralateral side (DBBM group). The graft materials on both sides were covered by a resorbable collagen membrane and fixation pins. Microcomputed tomographic volume and histomorphometric analyses were performed at 16 weeks post-surgery.

RESULTS

The ridges of both groups were recovered horizontally, but new bone formation beyond the original ridge contour at the defect site was not found. The DBBM group exhibited a larger total radiographic augmented volume and new bone volume compared with the DBBM/Auto group, but the differences were minimal (p > .05). Histologically, the regenerated area and new bone area were also slightly larger without any statistical significance in the DBBM group than in the DBBM/Auto group (p > .05).

CONCLUSION

The addition of autogenous bone chips to DBBM for lateral ridge augmentation may confer no advantage over grafting DBBM alone with respect to both space maintenance and de novo bone formation in dogs.

Cytocompatibility of Bone Substitute Materials and Membranes

BACKGROUND/AIM

With the demographic change and associated chronic bone loss, the need for cytocompatible bone replacement materials arise in modern medicine. The aim of this in vitro study was to investigate the cytocompatibility of eleven different bone substitute materials and membranes.

MATERIALS AND METHODS

Seven bone substitute materials and four membranes were assessed in vitro. The specimens were tested based on their interaction with MC3T3 pre-osteoblasts, through the utilization of viability, proliferation, and cytotoxicity assays. Cell vitality was evaluated using live-dead staining.

RESULTS

Although we found minor differences in cytocompatibility among the assessed materials, all tested materials can be considered as cytocompatible with a viability of more than 70% of the negative control, which indicates the non-toxic range as defined in current, international standards (DIN EN ISO 10993-5:2009, German Institute for Standardization, Berlin, Germany). Direct live-dead staining assays confirmed satisfactory cytocompatibility of all tested membranes.

CONCLUSION

All examined bone substitute materials and membranes were found to be cytocompatible. In order to assess whether the observed minor differences can impact regenerative processes, further in vivo studies need to be conducted.

Animal models of vertical bone augmentation (Review)

Vertical bone augmentation is an important challenge in dental implantology. Existing vertical bone augmentation techniques, along with bone grafting materials, have achieved certain clinical progress but continue to have numerous limitations. In order to evaluate the possibility of using biomaterials to develop bone substitutes, medical devices and/or new bone grafting techniques for vertical bone augmentation, it is essential to establish clinically relevant animal models to investigate their biocompatibility, mechanical properties, applicability and safety. The present review discusses recent animal experiments related to vertical bone augmentation. In addition, surgical protocols for establishing relevant preclinical models with various animal species were reviewed. The present study aims to provide guidance for selecting experimental animal models of vertical bone augmentation.

Comprehensive treatment for severe periodontitis with pathologic tooth migration-related bimaxillary protrusion: A case report with 3-year follow-up

BACKGROUND AND OVERVIEW

Patients with severe periodontitis often experience pathologic tooth migration (PTM), which impairs esthetics and leads to occlusal disharmony (for example, premature contacts and traumatic occlusion) that can further exacerbate periodontitis. The authors describe a patient who exhibited severe periodontitis with PTM-related bimaxillary protrusion. This report includes 3-year clinical outcomes after periodontal regenerative therapy, implant-anchored orthodontic therapy, and implant prosthodontics intended to achieve both functional and esthetic improvements.

CASE DESCRIPTION

A 63-year-old woman sought treatment with the chief complaint of maxillary anterior tooth mobility. Clinical examination revealed excessive tooth mobility, deep periodontal pockets, and infrabony defects in all teeth. All teeth exhibited PTM; the mandibular anterior teeth exhibited marked protrusion caused by the progression of periodontitis. After initial periodontal therapy, periodontal regenerative therapy was performed in all molar regions. At 6 and 9 months postoperatively, comprehensive orthodontic treatment was initiated for the mandible and maxilla, respectively, using orthodontic anchorage devices to achieve acceptable functional occlusion. After orthodontic treatment, staged guided bone regeneration was performed and dental implants were placed in the severely resorbed maxillary anterior ridge. This comprehensive treatment yielded favorable periodontal conditions, stable occlusion, and good esthetic outcomes.

CONCLUSIONS AND PRACTICAL IMPLICATIONS

Favorable esthetics, stable occlusion, and highly cleansable periodontal tissues were achieved with well-planned interdisciplinary and comprehensive treatment, although the patient had severe periodontitis and PTM-related bimaxillary protrusion.

Physical and biological performances of a semi-resorbable barrier membrane based on silk fibroin-glycerol-fish collagen material for guided bone regeneration

The fragility of silk fibroin film is a drawback to being used as a barrier membrane. Semi-resorbable barrier membranes maintain function longer than a resorbable membrane and no need to be removed. The study aimed to fabricate semi-resorbable membranes using silk fibroin with glycerol plasticizer (Group A), immobilized with fish collagen (Group B), and then characterized, in vitro biocompatibility tested, and compared with a commercial collagen membrane (Group C). Group B showed more roughness (0.2155 µm) than Group A (0.1424 µm). Group A was more hydrophilic (76.75° ± 3.07°) and more stiffness (28.93% ± 15.56%) than Group B (112.67° ± 1.94°, 42.10% ± 11.46%) and C (54.79% ± 13.44%) without significant difference. Group C had a significantly higher (p < 0.05) swelling degree and less degradation rate than others. Group A showed significantly highest (p < 0.05) cell proliferation. Group C showed more alkaline phosphatase activity than others but no significant difference in osteocalcin and Alizarin Red activity on day 21. The semi-resorbable membrane based on silk fibroin-glycerol possessed good physical and mechanical properties, and well-supported osteoblastic cell proliferation and differentiation.

Comparing the Efficacy of a Microperforated Titanium Membrane for Guided Bone Regeneration with an Existing Mesh Retainer in Dog Mandibles

Acute-type lateral ridge defects (25 mm × 6 mm × 5 mm) were bilaterally created in the mandibles of four dogs (two defects per animal). The defects were reconstructed with particulate autologous bone and covered with a microperforated titanium membrane (Ti-honeycomb membrane, TiHM) or an existing conventional titanium mesh as control. The samples were dissected after 16 weeks postoperatively and processed for radiographic, histologic, and histomorphometric analyses. Regenerated tissue and bone volume were significantly larger in the TiHM group than in the control group (p = 0.05; p = 0.049). In contrast, bone mineral density was similar between the two groups. Histomorphometric analysis revealed that the regenerated bone area and calcific osseous area were larger in the TiHM group than in the control group; however, the differences were not significant. The efficacy of TiHM was generally satisfactory with the potential to become a standard tool for the GBR procedure; however, early membrane exposure will be a major problem to overcome.