Effect of flapless ridge preservation with two different alloplastic materials in sockets with buccal dehiscence defects-volumetric and linear changes

Horizontal and Vertical Defect Management with a Novel Degradable Pure Magnesium Guided Bone Regeneration (GBR) Membrane-A Clinical Case

Background and objectives: In guided bone regeneration (GBR), large defects comprising both horizontal and vertical components usually require additional mechanical support to stabilize the augmentation and preserve the bone volume. This additional support is usually attained by using non-resorbable materials. A recently developed magnesium membrane presents the possibility of providing mechanical support whilst being completely resorbable. The aim of this case report was to describe the application and outcome of the magnesium membrane in combination with a collagen pericardium membrane for GBR. Materials and methods: A 74 year old, in an otherwise good general health condition, was presented with stage 2 grade A periodontitis and an impacted canine. After extraction of the impacted canine, a defect was created with both vertical and horizontal components. The defect was augmented using the magnesium membrane to create a supportive arch to the underlying bone graft and a collagen pericardium membrane was placed on top to aid with the soft tissue closure. Results: Upon reentry at 8 months, complete resorption of the magnesium devices was confirmed as there were no visible remnants remaining. A successful augmentation outcome had been achieved as the magnesium membrane in combination with the collagen membrane had maintained the augmented bone well. Two dental implants could be successfully placed in the healed augmentation. Conclusions: In this case, the magnesium membrane in combination with a collagen pericardium membrane presented a potentially viable alternative treatment to titanium meshes or titanium-reinforced membranes for the augmentation of a defect with both horizontal and vertical components that is completely resorbable. It was demonstrated that it is possible to attain a good quality and quantity of bone using a resorbable system that has been completely resorbed by the time of reentry.

Guided Bone Regeneration Using a Novel Magnesium Membrane: A Literature Review and a Report of Two Cases in Humans

Guided bone regeneration (GBR) is a common procedure used to rebuild dimensional changes in the alveolar ridge that occur after extraction. In GBR, membranes are used to separate the bone defect from the underlying soft tissue. To overcome the shortcomings of commonly used membranes in GBR, a new resorbable magnesium membrane has been developed. A literature search was performed via MEDLINE, Scopus, Web of Science and PubMed in February 2023 for research on magnesium barrier membranes. Of the 78 records reviewed, 16 studies met the inclusion criteria and were analyzed. In addition, this paper reports two cases where GBR was performed using a magnesium membrane and magnesium fixation system with immediate and delayed implant placement. No adverse reactions to the biomaterials were detected, and the membrane was completely resorbed after healing. The resorbable fixation screws used in both cases held the membranes in place during bone formation and were completely resorbed. Therefore, the pure magnesium membrane and magnesium fixation screws were found to be excellent biomaterials for GBR, which supports the findings of the literature review.

Application of Biodegradable Magnesium Membrane Shield Technique for Immediate Dentoalveolar Bone Regeneration

For the first time, the clinical application of the first CE registered magnesium membrane is reported. Due to the material characteristics of magnesium metal, new treatment methodologies become possible. This has led to the development of a new technique: the magnesium membrane shield technique, used to rebuild the buccal or palatal walls of compromised extraction sockets. Four clinical cases are reported, demonstrating the handling options of this new technique for providing a successful regenerative outcome. Using the technique, immediate implant placement is possible with a provisional implant in the aesthetic zone. It can also be used for rebuilding both the buccal and palatal walls simultaneously. For instances where additional mechanical support is required, the membrane can be bent into a double layer, which additionally provides a rounder edge for interfacing with the soft tissue. In all reported clinical cases, there was a good bone tissue regeneration and soft tissue healing. In some instances, the new bone had formed a thick cortical bone visible in cone beam computed tomography (CBCT) radiographs of the regenerated sites, which is known to be remodeled in the post treatment period. Overall, the magnesium membrane shield technique is presented as an alternative treatment option for compromised extraction sockets.

Degradable Pure Magnesium Used as a Barrier Film for Oral Bone Regeneration

The barrier membrane plays an extremely critical role in guided bone regeneration (GBR), which determines the success or failure of GBR technology. In order to obtain barrier membranes with high mechanical strength and degradability, some researchers have focused on degradable magnesium alloys. However, the degradation rate of pure Mg-based materials in body fluids is rather fast, thus posing an urgent problem to be solved in oral clinics. In this study, a novel micro-arc oxidation (MAO) surface-treated pure Mg membrane was prepared. Electrochemical tests, immersion experiments and in vivo experiments were carried out to investigate its potential use as a barrier membrane. The experimental results showed that the corrosion resistance of a pure Mg membrane treated by MAO is better than that of the uncoated pure Mg. The results of cell experiments showed no obvious cytotoxicity, which suggests the enhanced differentiation of osteoblasts. At the same time, the MAO-Mg membrane showed better biological activity than the pure Ti membrane in the early stage of implantation, exhibiting relatively good bone regeneration ability. Consequently, the MAO membrane has been proven to possess good application prospects for guided bone regeneration.

Biodegradable magnesium barrier membrane used for guided bone regeneration in dental surgery

Barrier membranes are commonly used as part of the dental surgical technique guided bone regeneration (GBR) and are often made of resorbable collagen or non-resorbable materials such as PTFE. While collagen membranes do not provide sufficient mechanical protection of the covered bone defect, titanium reinforced membranes and non-resorbable membranes need to be removed in a second surgery. Thus, biodegradable GBR membranes made of pure magnesium might be an alternative. In this study a biodegradable pure magnesium (99.95%) membrane has been proven to have all of the necessary requirements for an optimal regenerative outcome from both a mechanical and biological perspective. After implantation, the magnesium membrane separates the regenerating bone from the overlying, faster proliferating soft tissue. During the initial healing period, the membrane maintained a barrier function and space provision, whilst retaining the positioning of the bone graft material within the defect space. As the magnesium metal corroded, it formed a salty corrosion layer and local gas cavities, both of which extended the functional lifespan of the membrane barrier capabilities. During the resorption of the magnesium metal and magnesium salts, it was observed that the membrane became surrounded and then replaced by new bone. After the membrane had completely resorbed, only healthy tissue remained. The in vivo performance study demonstrated that the magnesium membrane has a comparable healing response and tissue regeneration to that of a resorbable collagen membrane. Overall, the magnesium membrane demonstrated all of the ideal qualities for a barrier membrane used in GBR treatment.

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First report on a biodegradable metallic barrier membrane for use in oral surgery is presented.

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The mechanical stability of the metallic barrier membrane provides a careful shielding of the augmented bone defect.

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Full resorption of metallic barrier membrane and bone healing is completed long before current standards for second surgical patient treatment.

Innovative Concepts and Recent Breakthrough for Engineered Graft and Constructs for Bone Regeneration: A Literature Systematic Review

Background: For decades, regenerative medicine and dentistry have been improved with new therapies and innovative clinical protocols. The aim of the present investigation was to evaluate through a critical review the recent innovations in the field of bone regeneration with a focus on the healing potentials and clinical protocols of bone substitutes combined with engineered constructs, growth factors and photobiomodulation applications. Methods: A Boolean systematic search was conducted by PubMed/Medline, PubMed/Central, Web of Science and Google scholar databases according to the PRISMA guidelines. Results: After the initial screening, a total of 304 papers were considered eligible for the qualitative synthesis. The articles included were categorized according to the main topics: alloplastic bone substitutes, autologous teeth derived substitutes, xenografts, platelet-derived concentrates, laser therapy, microbiota and bone metabolism and mesenchymal cells construct. Conclusions: The effectiveness of the present investigation showed that the use of biocompatible and bio-resorbable bone substitutes are related to the high-predictability of the bone regeneration protocols, while the oral microbiota and systemic health of the patient produce a clinical advantage for the long-term success of the regeneration procedures and implant-supported restorations. The use of growth factors is able to reduce the co-morbidity of the regenerative procedure ameliorating the post-operative healing phase. The LLLT is an adjuvant protocol to improve the soft and hard tissues response for bone regeneration treatment protocols.

[Influencing Hard and Soft Tissue Changes Following Tooth Extraction]

Influencing Hard and Soft Tissue Changes Following Tooth Extraction Abstract. Influencing Hard and Soft Tissue Changes Following Tooth Extraction The loss of a tooth leads to the initiation of resorption processes and thus to the remodeling of the tissues of the alveolar process. At the hard tissue level, this resorption mainly affects the bundle bone at the buccal side of the extracted tooth and occurs most rapidly in the first weeks and months after extraction. Tissue changes occur not only at the level of the hard tissue (bone), but also at the level of the soft tissue. These changes lead to a significant loss of volume, especially at the buccal area of the alveolar ridge. They are responsible for a volume loss of the alveolar ridge contour of up to 50 %.

Combination of bone substitutes and vectors in periodontology and implantology: A systematic review

The aim of the systematic review was to analyze the use of combination of bone substitutes and vectors in periodontology and implantology among animals models and humans. Electronic databases were searched, and additional hand search was performed. The research strategy was achieved according to the PRISMA guidelines. The including criteria were: combination of bone substitutes and vectors, in vivo studies, a precise number of specimens, histological and radiographic analysis, written in English. The risk of bias was evaluated for individual studies. Thirty-two articles were selected and investigated in this systematic review. The results do not show a superiority of the use of composite biomaterial in comparison with simple biomaterial but suggest the efficacity of their utilization as a carrier of bioactive agents. Future studies need to identify the suitable association of bone substitutes and vectors and explore interest in their use such as the support of growth factors.

[Efficacy of two barrier membranes and deproteinized bovine bone mineral on bone regeneration in extraction sockets: A microcomputed tomographic study in dogs]

OBJECTIVE

To evaluate the effect of two barrier membranes [multilaminated small intestinal submucosa (mSIS) and bioresorable collagen membrane (Bio-Gide)] combined with deproteinized bovine bone mineral Bio-Oss on guided bone regeneration through a canine extraction sockets model.

METHODS

The distal roots of 18 premolars of the Beagle' s bilateral maxillary and mandibular were removed, and 18 extraction sockets were obtained. They were randomly divided into 3 groups, and the following procedures were performed on the sockets: (1) filled with Bio-Oss and covered by mSIS (mSIS group), (2) filled with Bio-Oss and covered by Bio-Gide (BG group), (3) natural healing (blank control group). Micro-computed tomograph (Micro-CT) was performed 4 and 12 weeks after surgery to eva-luate the new bone regeneration in the sockets of each group.

RESULTS

The postoperative healing was uneventful in all the animals, and no complications were observed through the whole study period. Micro-CT analysis showed that the new bone fraction in the mSIS group and the BG group was significantly higher than that in the blank control group at the end of 4 weeks and 12 weeks (P < 0.05), and more new bone fraction was observed in the mSIS group than in the BG group, but the difference was not statistically significant (P>0.05). The new bone fraction of coronal third part of the socket in the mSIS group and BG group at the end of 4 weeks were significantly higher than that of the middle and apical third part of each group (P < 0.05). The values of bone mineral density were similar at 4 weeks in all the groups (P>0.05), but were significantly higher than that in the control group at the end of 12 weeks (P < 0.05). The bone morphometric analysis showed that the trabecular number and trabecular spacing were significantly better in the mSIS group and the BG group than in the control group at the end of 4 weeks and 12 weeks (P < 0.05), while the value in the mSIS group was slightly higher than in the BG group, but the difference was not statistically significant (P>0.05). The difference in trabecular thickness between all the groups was not statistically significant (P>0.05).

CONCLUSION

mSIS membrane as a barrier membrane combined with deproteinized bovine bone mineral can enhance new bone formation in canine extraction sockets, similar to Bio-Gide collagen membrane.

Ridge Augmentation Using β-Tricalcium Phosphate and Biphasic Calcium Phosphate Sphere with Collagen Membrane in Chronic Pathologic Extraction Sockets with Dehiscence Defect: A Pilot Study in Beagle Dogs

This study was conducted to comparatively examine spontaneous healing versus ridge augmentation, in surgically-created dehiscence defects, associated with chronic pathology in dogs. Mandibular second, third and fourth premolars (P2, P3 and P4) were hemi-sectioned, and a dehiscence defect was created at the mesial root, while a groove was made on the buccal area from the top of the teeth to the bottom of the defect, exposing the dental pulp. The mesial roots of P2, P3 and P4 were extracted 1 month after the induction of the dehiscence defect with chronic pathology. Three teeth were randomly allocated to these experimental groups: (i) spontaneous healing without any bone graft (Control group: C); (ii) ridge augmentation with β-tricalcium phosphate (β-TCP) granules (Test 1 group: T1); and (iii) ridge augmentation with 60% hydroxyapatite (HA) and 40% β-TCP microspheres (Test 2 group: T2). Postmortem histopathologic examination showed significant between-group differences in C and T1 and C and T2 in bone volume/tissue volume in qualitative micro-computed tomography (CT) analysis, as well as significant intergroup differences in the coronal area at 4 and 12 weeks. The composition of connective tissue and mineralized bone in C and T1 were higher than in T2 at 4 weeks of healing, whereas the composition of mineralized bone was higher in T2 than in T1 at 12 weeks of healing. Biphasic calcium phosphate, composed of 60% HA and 40% β-TCP microsphere (i) potentially prevented marked osteoclastic resorption and (ii) promoted ridge preservation in the extraction socket with the dehiscence defect and chronic pathology.

Biphasic Calcium Phosphate Sphere Graft Combined with a Double-Layer Non-Crosslinked Collagen Membrane Technique for Ridge Preservation: A Randomized Controlled Animal Study

The purpose of this study was to compare the histologic and radiologic differences between single- and double-layer collagen membrane techniques in flapless ridge preservation. The mandibular fourth premolar and first molar of four beagle dogs were used in the experiment. Mesial roots of the teeth were extracted and root canal treatment was performed at the distal roots. Ridge preservation was performed at the extraction sites using synthetic bone graft material. A single layer (control group) or double layer (test group) of non-crosslinked collagen membrane was applied following bone graft application. Three months later, the animals were sacrificed and micro-computed tomography (micro-CT) and histomorphometric analyses were conducted. Nonparametric Mann-Whitney test was performed to compare between the control and test groups. The vertical difference between buccal and lingual crests of control and test groups was 1.28 ± 0.41 and 0.53 ± 0.37 mm, respectively (p = 0.026). The mineralized bone area in control and test groups was 31.48% ± 7.41% and 42.25% ± 9.73%, respectively (p = 0.041). Within the limit of this study, ridge preservation using the double-layer membrane technique showed a reduced buccal bone resorption and improved new-bone formation in the ridge compared to that using the single-layer membrane technique.

Effects of local application of alendronate on early healing of extraction socket in dogs

OBJECTIVE

The aim of the present study was to assess the effects of alendronate (ALN) on bone remodeling following tooth extraction in a dog model.

MATERIAL AND METHODS

For the study, fifteen male Beagles dogs of approximately 12 months of age were used. Mesial roots of four mandibular premolars were endodontically treated, and the distal roots were removed. ALN concentrations of 0.5, 1, and 2 mg/mL were topically applied for 15 min, while a sterile saline was used as a negative control. After the healing period of 1, 2, and 8 weeks, the samples were analyzed by micro-CT and histology.

RESULTS

Treatment with ALN increased vertical distance between the lingual and the buccal crestal bones. While the ALN-treated sockets had preserved more lingual bone areas, control sockets showed better preservation of the buccal bone areas. ALN treatment resulted in more osteoid formation within the extraction sockets compared with the control. Higher bone volume was found in ALN groups than in the control at 2-week and 8-week healing periods, reaching the significant difference only for the extraction sockets pooled for the ALN treatment.

CONCLUSIONS

Although ALN treatment could not prevent buccal bone resorption following tooth extraction in dogs, it proved beneficial for the preservation of the lingual bone and formation of new bone within the socket. There was no clear relation between the ALN dosages and the alterations within the extraction sockets.

CLINICAL RELEVANCE

ALN affects bone remodeling of the extraction socket. The optimal concentration remains to be determined in future studies.

Evaluation of an In Situ Hardening β-Tricalcium Phosphate Graft Material for Alveolar Ridge Preservation. A Histomorphometric Animal Study in Pigs

The purpose of this study was to investigate the effectiveness of a resorbable alloplastic in situ hardening bone grafting material for alveolar ridge preservation in a swine model. Seven Landrace pigs were used. In each animal, the maxillary left and right deciduous second molars were extracted, and extraction sites were either grafted with a resorbable alloplastic in situ hardening bone substitute, composed of beta-tricalcium phosphate (β-TCP) granules coated with poly(lactic-co-glycolic) acid (PLGA), or left unfilled to heal spontaneously. Animals were euthanized after 12 weeks, and the bone tissue was analyzed histologically and histomorphometrically. Linear changes of ridge width were also clinically measured and analyzed. Pronounced bone regeneration was found in both experimental and control sites, with no statistically significant differences. At the experimental sites, most of the alloplastic grafting material was resorbed and remnants of the graft particles were severely decreased in size. Moreover, experimental sites showed, in a statistically nonsignificant way, less mean horizontal dimensional reduction of the alveolar ridge (7.69%) compared to the control sites (8.86%). In conclusion, the β-TCP/PLGA biomaterial performed well as a biocompatible resorbable in situ hardening bone substitute when placed in intact extraction sockets in this animal model.