Guided bone regeneration in distal mandibular atrophy by means of a preformed titanium foil: a case series.

The aim of this case series was to evaluate the clinical outcome of preformed titanium foil (PTF) to perform guided bone regeneration (GBR) in posterior mandibular atrophies. Thirteen patients (4 male; 9 female; mean age 58.85±10.16 years), with class II division C atrophy, according to Misch, were selected to perform GBR by means of PTF, using a moldable allograft paste as graft material. The devices, made of a 0.2mm thick pure titanium foil, were pre-shaped using stereolithographic models obtained from CT-scan of the patients’ recipient sites. In the second stage, performed at 6.35±2.15 months, 23 cylindrical two-piece implants were placed and the devices removed. At four months, the implants were exposed and submitted to progressive prosthetic load for a span of 4 months. The cases were finalized by means of metal-ceramic cementable restorations. The post finalization follow-up was at 12 months. Survival rate (i.e. SVR) was 100% since no fixtures were lost. At the one-year follow up, the clinical appearance of the soft tissues was optimal and no pathological signs on probing were recorded. The success rate (i.e. SCR) was 82.6% and the average peri-implant bone reabsorption was 0.99±0.59 mm. The results suggest good potentialities of this method for bone volume augmentation in distal mandibular atrophies, allowing to maximize the outcome and simplifying the surgical phase.

Guided Tissue Regeneration in Four Teeth Using a Liquid Polymer Membrane.

Periodontal disease is one of the most common diseases diagnosed in dogs and cats. Guided tissue regeneration (GTR) is a treatment alternative to extraction of strategically important teeth. The barrier membrane used in the GTR procedure is of key importance. The purpose of this case series was to evaluate a liquid polymer gel as a membrane for GTR. The polymer gel ( N-methyl-2-pyrrolidone and poly [DL-lactide]) combined with 8.5% doxycycline hyclate was used in place of a traditional membrane in 4 teeth. The teeth were re-examined 6 months postoperatively for radiographic evaluation. A decrease in probing depth and new alveolar bone formation was seen 6 months postoperatively. Improvement in periodontal disease stage was seen in 2 of the 4 teeth. Larger controlled trials with histopathologic evaluation are indicated to further assess the use of this polymer as a membrane in GTR. However, the clinical outcomes of all 4 treated teeth were considered successful.

Novel MesoPorous BioGlass/silk scaffold containing adPDGF-B and adBMP7 for the repair of periodontal defects in beagle dogs.

AIM: The local delivery of growth factors via gene therapy has gained tremendous awareness in recent years due to their sustained growth factor delivery to target tissues. The aim of this study was to fabricate and investigate a scaffold able to release growth factors via gene therapy for the repair of periodontal tissues. MATERIALS AND METHODS: Novel mesoporous bioglass (MBG)/silk fibrin scaffold combined with BMP7 and/or PDGF-B adenovirus was fabricated and tested in vitro for cell migration, proliferation and differentiation. Furthermore, acute-type buccal dehiscence periodontal defects (mesiodistal width × depth: 5 × 5 mm) were created on the buccal portion of the maxillary premolars in five normal male beagle dogs (12 months old, 15.0 ± 2.0 kg) and histologically examined for periodontal regeneration following implantation of the following five groups: (1) no scaffold, (2) MBG/silk scaffold alone, (3) scaffold + adPDGF-B, (4) scaffold + adBMP7, (5) scaffold + adPDGF-b + adBMP7. RESULTS: In vitro findings demonstrated that adPDGF-B was able to rapidly recruit periodontal ligament (PDL) cells over sixfold more effectively than adBMP7, whereas adBMP7 was more able to induce osteoblast differentiation of PDL cells. In vivo findings demonstrate that scaffolds loaded with adPDGF-B were able to partially regenerate the periodontal ligament while adBMP7 scaffolds primarily improved new bone formation. The combination of both adPDGF-B and adBMP7 synergistically promoted periodontal regeneration by allowing up to two times greater regeneration of the periodontal ligament, alveolar bone and cementum when compared to each adenovirus used alone. CONCLUSIONS: Although both PDGF-B and BMP7 are individually capable of promoting periodontal regeneration to some degree, their combination synergistically promotes wound healing in acute-type buccal dehiscence periodontal defects when delivered simultaneously. This study demonstrates the promise for successful delivery of low-cost, effective growth factor delivery via gene therapy for the treatment of periodontal defects.

Evaluation of the Antibacterial Effect of Silver Nanoparticles on Guided Tissue Regeneration Membrane Colonization--An in Vitro Study.

OBJECTIVE: The aim of this in vitro study was to investigate the colonization and penetration of specific bacteria on nanosilver-impregnated GTR (guided tissue regeneration) membranes. METHODS: Three sets of GTR membranes were used in this study: 1) GTR-C: Plain GTR membrane as a negative control; 2) GTR-NS: GTR membrane impregnated with silver nanoparticles as the test group; 3) GTR-DOX: GTR membrane impregnated with 25% (w/w) doxycycline hydrochloride acting as a positive control. Stress-strain characteristics were calculated to determine the physical properties of the control and impregnated membranes. Qualitative observation of microbial adherence and bacterial penetration through GTR membranes were performed by using four organisms (Streptococcus mutans, Aggregatibacter actinomycetemcomitans, Fusobacterium nucleatum and Porphyromonas gingivalis) reported to have strong adherent capabilities to collagen membranes. RESULTS: The mean bacterial adherence scores were significantly greater (p < 0.001) in the GTR-C group when compared to GTR-DOX and GTR-NS groups. GTR-NS showed lower adherence scores than GTR-DOX across all four microorganisms; this difference, however was not statistically significant. The difference in colony forming units (CFUs) was highly significant (p < 0.001), suggesting greater penetration in GTR-C membranes when compared to GTR-NS and GTR-DOX groups. Though the mean CFUs were lower in GTR-DOX than in GTR-NS across all four microorganisms, this difference was statistically significant only for S. mutans and F. nucleatum. CONCLUSION: The incorporation of silver nanoparticles may be of value when controlling membrane-associated infection. Studies with different nanosilver particle sizes should be conducted to further evaluate the beneficial properties of nanosilver against periodontal pathogens.

Human dental pulp stem cells cultured onto dentin derived scaffold can regenerate dentin-like tissue in vivo.

Regeneration of dentin tissues in the pulp space of teeth serves the ultimate goal of preserving teeth via endodontic approaches. In recent times, many studies suggested that human dentin scaffolds combined with dental stem cells was a potential strategy for the complete dentin tissue regeneration. In this study, human dental pulp stem cells (DPSCs) were isolated and cultured. Dentin specimens were prepared from human third molars and treated with ethylene diamine tetra-acetic acid and citric acid to remove the smear layer. Then, DPSCs were cultured onto human treated dentin (hTD) and implanted in mouse model for 4, 6 and 8 weeks. The resulting grafts were assessed by hematoxylin and eosin stain and immunohistochemical stains. As a result, DPSCs were supported and induced to regenerate of dentin-like tissues which expressed specific dentin markers such as dentin sialophosphoprotein and dentin matrix protein 1 by combination with hTD in vivo. Furthermore, cells existed in the newly-formed dentin-like tissues also expressed typical human mitochondria antibodies, demonstrated that new tissues originated from human. In conclusion, the obtain results extend hopefully newly-established therapy to apply in endodontics and traumatic dental hard tissues.

Horizontal-guided Bone Regeneration using a Titanium Mesh and an Equine Bone Graft.

AIM: The present work describes a horizontal ridge augmentation in which a titanium mesh was preshaped by adapting it to a stereolithographic model of the patient's jaw that was fabricated from CT scans. BACKGROUND: Guided bone regeneration (GBR) involves covering the augmentation site with a long-lasting barrier to protect it from the invasion of surrounding soft tissues. Among barriers, titanium meshes may provide a successful outcome, but the intraoperatory time needed to shape them is a disadvantage. CASE DESCRIPTION: The 54-year-old patient, missing the right mandibular second bicuspid, first molar, and second molar, had her atrophic ridge augmented with a 30:70 mixture of autogenous bone and equine, enzyme-deantigenic collagen-preserved bone substitute. Two conical implants were inserted concomitantly in the second bicuspid and first molar positions, and the site was protected with the preshaped mesh. Four months later, the titanium mesh was retrieved, a bone sample was collected, and histological and histomorphometric analyses were performed. Provisional and definitive prostheses were then delivered, and follow-up controls were performed for up to 24 months. CONCLUSION: Preshaping the mesh on a model of the patient's mandible shortened the surgical time and enabled faster mesh placement. Two years after surgery, the implants were perfectly functional, and the bone width was stable over time as shown by radiographic controls. Histological analysis of the bone sample showed the heterologous biomaterial to be biocompatible and undergoing advanced remodeling and replacement with newly formed bone. CLINICAL SIGNIFICANCE: Preshaping a titanium mesh over a stereolithographic model of the patient's jaw allowed for a significant reduction of the intraoperative time and may be therefore, advisable in routine practice.

Horizontal bone augmentation by means of guided bone regeneration.

The development of bone augmentation procedures has allowed placement of dental implants into jaw bone areas lacking an amount of bone sufficient for standard implant placement. Thus, the indications for implants have broadened to include jaw regions with bone defects and those with a bone anatomy that is unfavorable for implant anchorage. Of the different techniques, the best documented and the most widely used method to augment bone in localized alveolar defects is guided bone regeneration. A large body of evidence has demonstrated the successful use of guided bone regeneration to regenerate missing bone at implant sites with insufficient bone volume and the long-term success of implants placed simultaneously with, or after, guided bone regeneration. However, the influence of guided bone regeneration on implant survival and success rates, and the long-term stability of the augmented bone, remain unknown. Many of the materials and techniques currently available for bone regeneration of alveolar ridge defects were developed many years ago. Recently, various new materials and techniques have been introduced. Many of them have, however, not been sufficiently documented in clinical studies. The aim of this review was to present the scientific basis of guided bone regeneration and the accepted clinical procedures. A classification of bone defects has been presented, aiming at simplifying the decision-making process regarding the choice of strategy for bone augmentation. Finally, an outlook into actual research and the possible future options related to bone augmentation has been provided.

Advanced tissue engineering scaffold design for regeneration of the complex hierarchical periodontal structure.

AIM: This study investigated the ability of an osteoconductive biphasic scaffold to simultaneously regenerate alveolar bone, periodontal ligament and cementum. MATERIALS AND METHODS: A biphasic scaffold was built by attaching a fused deposition modelled bone compartment to a melt electrospun periodontal compartment. The bone compartment was coated with a calcium phosphate (CaP) layer for increasing osteoconductivity, seeded with osteoblasts and cultured in vitro for 6 weeks. The resulting constructs were then complemented with the placement of PDL cell sheets on the periodontal compartment, attached to a dentin block and subcutaneously implanted into athymic rats for 8 weeks. Scanning electron microscopy, X-ray diffraction, alkaline phosphatase and DNA content quantification, confocal laser microscopy, micro computerized tomography and histological analysis were employed to evaluate the scaffold's performance. RESULTS: The in vitro study showed that alkaline phosphatase activity was significantly increased in the CaP-coated samples and they also displayed enhanced mineralization. In the in vivo study, significantly more bone formation was observed in the coated scaffolds. Histological analysis revealed that the large pore size of the periodontal compartment permitted vascularization of the cell sheets, and periodontal attachment was achieved at the dentin interface. CONCLUSIONS: This work demonstrates that the combination of cell sheet technology together with an osteoconductive biphasic scaffold could be utilized to address the limitations of current periodontal regeneration techniques.

Gingival crevicular fluid bone morphogenetic protein-2 release profile following the use of modified perforated membrane barriers in localized intrabony defects: a randomized clinical trial.

BACKGROUND: In guided tissue regenerative surgery, membrane perforations may serve as a mechanism for the passage of cells and biologic mediators from the periosteum and overlying gingival connective tissue into the periodontal defects. To test this assumption, this study was designed to evaluate levels of bone morphogenetic protein-2 (BMP-2) in gingival crevicular fluid (GCF) during the early stages of healing for sites treated with modified perforated membranes (MPMs) as compared with occlusive membranes (OMs). METHODS: Fifteen non-smoking patients with severe chronic periodontitis participated in this prospective, randomized and single-blinded clinical trial. Each patient contributed two interproximal contralateral defects that were randomly assigned to either an experimental modified perforated membrane group (15 sites) or a control occlusive membrane group (15 sites). Plaque index, gingival index, probing depth(PD), clinical attachment level (CAL) and the relative intrabony depth of the defect (rIBD) were measured at baseline and reassessed at three, six and nine months after therapy. Gingival crevicular fluid samples were collected on day 1 and 3, 7, 14, 21, and 30 days after therapy. RESULTS: The MPM-treated group showed a statistically significant improvement in PD reduction and clinical attachment gain compared to the OM control group. Similarly, rIBD was significantly reduced in MPM-treated sites as compared with those of the OM group. BMP-2 concentrations peaked in the MPM samples obtained during the early postoperative period (days 1, 3 and 7) with a statistically significant difference compared with OM-treated groups. BMP-2 levels decreased sharply in the samples obtained at days 14, 21 and 30 with non-significant higher levels in MPM samples as compared with those of OM sites. CONCLUSION: Within the limits of the present study, one can conclude that MPM coverage of periodontal defects is associated with a significant initial increase in GCF levels of BMP-2, a factor that could improve the clinical outcomes of guided tissue regenerative surgery.

A two-stage surgical approach to the treatment of severe peri-implant defect: a 30-month clinical follow-up report.

With the advance of dental implant technology and the consequential increase in its success rate, the implant has become a highly predictable treatment method. Despite this, related complications are on the rise, with peri-implant mucositis and peri-implantitis being the most commonly observed. As in the case of conventional periodontitis, many patients experience peri-implant mucositis and peri-implantitis. In this case presentation, extensive bone loss occurred around the implant due to peri-implantitis, and the infection was first treated by applying chlorhexidine-soaked gauze and topical antibiotics. Then the guided bone regeneration procedure was performed using a bovine bone material and a collagen membrane, which resulted in the recovery of the lesion. With follow-ups of the healing process for 30 months, a successful outcome was observed that is reported herein.

Active implant peri-apical lesion: a case report treated via guided bone regeneration with a 5-year clinical and radiographic follow-up.

Implant peri-apical lesion (IPL) is a periapical lesion, usually asymptomatic, in which the coronal portion of the implant achieves a normal bone to implant interface. A case of IPL following immediate implant placement and treated with guided bone regeneration (GBR) principles is described. Five-year clinical and radiographic follow-up with cone-beam assessment showed complete healing of the bone. GBR principles applied to IPL could completely solve the lesion.

Periodontal repair in dogs: space-provision supports alveolar bone and cementum formation.

OBJECTIVE: Clinical criteria for periodontal wound healing/regeneration include wound stability, space-provision and conditions for primary intention healing. However, wound stability/space-provision may be difficult to obtain in non-contained periodontal defects. The objective of this study was to; using a limited, space-providing device as a conduit, evaluate a concept of space-provision sans tissue occlusion for periodontal wound healing/regeneration. METHODS: Bilateral, critical-size, supraalveolar, periodontal defects were created in eight young adult Beagle dogs. One jaw quadrant received a limited, space-providing titanium mesh device, the contra-lateral jaw quadrant served as sham-surgery control followed by submerged wound closure for primary intention healing. The animals were euthanized at 8 weeks for histometric analysis of the surgical sites. RESULTS: Clinical healing was generally uneventful; minor late exposures observed for some defects. Experimental sites exhibited significantly enhanced mean (±SE) bone and cementum regeneration compared with control (1.10 ± 0.20 and 1.32 ± 0.10 mm versus 0.34 ± 0.18 and 0.66 ± 0.15 mm; p < 0.01). A cellular mixed (extrinsic/intrinsic) fibre cementum and functionally oriented collagen fibres were routinely observed. Wound exposures were significantly associated with reduced bone formation (p < 0.05). CONCLUSIONS: Using a limited, space-providing device to support periodontal wound healing/regeneration appears a promising clinical approach for non-contained periodontal defects.

Effect of nano-hydroxyapatite suspension on cell proliferation and cycle in human periodontal ligament cells.

The study was aimed to provide insights into the effect of nano-hydroxyapatite (nHA) suspension on cell proliferation and cycle of human periodontal ligament cells, offering the evidence for nHA being used in periodontal therapy. Human periodontal ligament cells (HPDLCs) were cultured in different concentrations of nano-hydroxyapatite/sodium carboxymethyl cellulose (nHA-CMCNa) suspension in vitro. After that, cell proliferation ability was examined by MTT [3(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and flow cytometry. MTT assay demonstrated that the Relative Proliferation Rate (RPR) of 0.5% nHA-CMCNa group was significantly higher than other groups (p <0.05), which means that nHA-CMCNa might increase cell proliferation ability. Flow cytometry showed that cells in G1 phase decreased, whilst cells in S phase increased after cultured in nHA-CMCNa suspension for 48 h. The result suggested that part of cells finished G1 phase in advance and get into S phase earlier, which speed up the cell proliferation, nHA-CMCNa suspension had great effect on cell proliferation. The high concentration of nHA-CMCNa could shorten the time in G1 phase, impel part of cells into S phase, and accelerate proliferation rate of HPDLCs.

Purposeful exposure of a polylactic acid barrier to achieve socket preservation for placement of dental implants: case series report.

This retrospective case series reports on the use of a polylactic acid barrier that was left exposed in the process of socket preparation for the placement of dental implants. A retrospective chart review found 43 patients with 48 extraction sockets that were treated in this manner. Teeth were removed and the sockets were thoroughly debrided, with 40 of them receiving a bone replacement graft covered by the polylactic acid barrier and the additional 8 receiving the membrane alone. Suturing left the barrier exposed, and the sites were re-entered on average at 23 weeks for the placement of a dental implant. All sites were able to receive a dental implant, demonstrating the ability to leave a polylactic acid barrier exposed and achieve successful guided bone regeneration (GBR) results. This ultimately helped avoid some of the negative sequelae of trying to achieve primary closure of the flaps at the time of tooth extraction.

Utilizing collagen membranes for guided tissue regeneration-based root coverage.

Gingival recession is a common clinical problem that can result in hypersensitivity, pain, root caries and esthetic concerns. Conventional soft tissue procedures for root coverage require an additional surgical site, thereby causing additional trauma and donor site morbidity. In addition, the grafted tissues heal by repair, with formation of long junctional epithelium with some connective tissue attachment. Guided tissue regeneration-based root coverage was thus developed in an attempt to overcome these limitations while providing comparable clinical results. This paper addresses the biologic foundation of guided tissue regeneration-based root coverage, and describes the indications and contraindications for this technique, as well as the factors that influence outcomes. The step-by-step clinical techniques utilizing collagen membranes are also described. In comparison with conventional soft tissue procedures, the benefits of guided tissue regeneration-based root coverage procedures include new attachment formation, elimination of donor site morbidity, less chair-time, and unlimited availability and uniform thickness of the product. Collagen membranes, in particular, benefit from product biocompatibility with the host, while promoting chemotaxis, hemostasis, and exchange of gas and nutrients. Such characteristics lead to better wound healing by promoting primary wound coverage, angiogenesis, space creation and maintenance, and clot stability. In conclusion, collagen membranes are a reliable alternative for use in root coverage procedures.

Comparative evaluation of guided tissue regeneration with use of collagen-based barrier freeze-dried dura mater allograft for mandibular class 2 furcation defects (a comparative controlled clinical study).

AIM: The aim of periodontal surgery is complete regeneration. The present study was designed to evaluate and compare clinically soft tissue changes in form of probing pocket depth, gingival shrinkage, attachment level and hard tissue changes in form of horizontal and vertical bone level using resorbable membranes. MATERIALS AND METHODS: Twelve subjects with bilateral class 2 furcation defects were selected. After initial phase one treatment, open debridement was performed in control site while freezedried dura mater allograft was used in experimental site. Soft and hard tissue parameters were registered intrasurgically. Nine months reentry ensured better understanding and evaluation of the final outcome of the study. RESULTS: Guided tissue regeneration is a predictable treatment modality for class 2 furcation defect. There was statistically significant reduction in pocket depth as compared to control (p < 0.01). There is statistically significant increase in periodontal attachment level within control and experimental sites showed better results (p < 0.01). For hard tissue parameter, significant defect fill resulted in experimental group, while in control group, less significant defect fill was found in horizontal direction and nonsignificant defect fill was found in vertical direction. CONCLUSION: The results showed statistically significant improvement in soft and hard tissue parameters and less gingival shrinkage in experimental sites compared to control site. CLINICAL SIGNIFICANCE: The use of FDDMA in furcation defects helps us to achieve predictable results. This cross-linked collagen membrane has better handling properties and ease of procurement as well as economic viability making it a logical material to be used in regenerative surgeries.

Clinical and radiological evaluation of human osseous defects (mandibular grade ii furcation involvement) treated with bioresorbable membrane: vicryl mesh.

AIM: The purpose of the present study was to evaluate clinical and radiological healing effects after treatment of class II furcation defects using bioresorbable periodontal mesh barriers. MATERIALS AND METHODS: The patients for the following study were selected from Outpatient, Department of Periodontics, College of Dental Sciences, Davanagere, Karnataka. INCLUSION CRITERIA: 1. Patients with age group between 18 and 60 years. 2. Patients who were nonsmokers. 3. Patients who had not undergone any type of periodontal therapy 6 months prior to initial examination. 4. Patients diagnosed as advanced periodontitis having mandibular grade II furcation involvement (Glickman 1953) clinically and radiologically. EXCLUSION CRITERIA: 1. Patients who required antibiotic prophylaxis. 2. Patients allergic to tetracycline and/ or chlorhexidine. 3. Pregnant and lactating mother. 4. Patient showing unacceptable oral hygiene during presurgical (phase 1) therapy. RESULTS: In this study clinical parameters were compared and attempt was made to compare the results radiographically too, with the limitations, the present study showed that the use of resorbable periodontal mesh barriers for GTR therapy at class II furcations resulted in reduction of furcation involvement. CONCLUSION: Therefore it appears that a patient with class II furcations involvement benefits from barrier treatment, because results are superior to conventional treatment without barriers. CLINICAL SIGNIFICANCE: The present study was taken up to evaluate the clinical effects of GTR therapy of class II furcations using bioresorbable periodontal mesh barriers.

Long-term stability of surgical bone regenerative procedures of peri-implantitis lesions in a prospective case-control study over 3 years.

OBJECTIVES: To evaluate the extent of bone fill over 3 years following the surgical treatment of peri-implantitis with bone grafting with or without a membrane. MATERIAL AND METHODS: In a non-submerged wound-healing mode, 15 subjects with 27 implants were treated with a bone substitute (Algipore(®)) alone and 17 subjects with 29 implants were treated with the bone substitute and a resorbable membrane (Osseoquest(®)). Implants with radiographic bone loss ≥1.8 mm following the first year in function and with bleeding and/or pus on probing were included. Following surgery, subjects were given systemic antibiotics (10 days) and rinsed with chlorhexidine. After initial healing, the subjects were enrolled in a strict maintenance programme. RESULTS: Statistical analysis failed to demonstrate changes in bone fill between 1 and 3 years both between and within procedure groups. The mean defect fill at 3 years was 1.3 ± (SD) 1.3 mm if treated with the bone substitute alone and 1.6 ± (SD) 1.2 mm if treated with an adjunct resorbable membrane, (p=0.40). The plaque index decreased from approximately 40-10%, remaining stable during the following 2 years. CONCLUSION: Defect fill using a bone substitute with or without a membrane technique in the treatment of peri-implantitis can be maintained over 3 years.

The effect of non-resorbable membrane on buccal bone healing at an immediate implant site: an experimental study in dogs.

OBJECTIVE: For successful implant treatment in the esthetic area, stable hard tissue and soft tissue are very important. At the buccal side without buccal bone defects, prophylactic guided bone regeneration (GBR) with bone substitute was frequently used for achieving thick buccal bone. The aim of this study was to evaluate the effect of GBR using a non-resorbable membrane in an immediate implant site without bone defects. MATERIAL AND METHODS: Immediate implants were placed into the mandibles of four mongrel dogs. In the experimental group (TM group), a non-resorbable membrane was placed and fixed onto the buccal bone plate around the implant. In the control group, the implants were placed without membrane coverage. After 12 weeks, the dogs were sacrificed and histological specimens were prepared. The vertical distances from the smooth-rough surface interface (SRI) to the gingiva, the first-bone contact, and the bone crest were measured on the buccal and lingual sides. The horizontal thicknesses of the gingiva and bone at 0, 1, 2, and 3 mm below the SRI were measured. RESULTS: In the TM group, first-bone contact on the buccal side was more coronally positioned approximately 0.8 mm than the control group (P=0.041). The buccal bone thickness of the TM group was well preserved and there was no difference between the buccal and lingual sides. Comparing the control group, implants of the TM group had 1 mm thicker buccal bone (P=0.0051 at bone 1 mm level, P=0.002 at bone 2 mm level). In the control group, buccal bone loss was observed and buccal bone was about 1 mm thinner than the lingual bone (P<0.05). CONCLUSIONS: GBR with a non-resorbable membrane and no bone graft substitute could help to preserve buccal bone thickness on the immediate implant site without defects.

Degradable polymers may improve dental practice.

The use of biomaterials in dentistry is more widespread than in any other medical field in terms of both amount and variety. Most of them were not originally designed for dental applications but for other medical applications or, sometimes, for no medical purposes. Among these materials, biodegradable materials play an important role, especially in bone regeneration and in periodontal surgery. This paper briefly reviews some degradable polymers developed as tools for the treatment of periodontal and bone diseases. We discuss materials previously applied in other industrials contexts, such as polyesters, methylcellulose, and chitosan and we provide perspectives for their use in periodontal regeneration.