Comparison of two resorbable membrane systems in bone regeneration after removal of wisdom teeth: a randomized-controlled clinical pilot study

Guided Tissue and Bone Regeneration Membranes: A Review of Biomaterials and Techniques for Periodontal Treatments

This comprehensive review provides an in-depth analysis of the use of biomaterials in the processes of guided tissue and bone regeneration, and their indispensable role in dental therapeutic interventions. These interventions serve the critical function of restoring both structural integrity and functionality to the dentition that has been lost or damaged. The basis for this review is laid through the exploration of various relevant scientific databases such as Scopus, PubMed, Web of science and MEDLINE. From a meticulous selection, relevant literature was chosen. This review commences by examining the different types of membranes used in guided bone regeneration procedures and the spectrum of biomaterials employed in these operations. It then explores the manufacturing technologies for the scaffold, delving into their significant impact on tissue and bone regenerations. At the core of this review is the method of guided bone regeneration, which is a crucial technique for counteracting bone loss induced by tooth extraction or periodontal disease. The discussion advances by underscoring the latest innovations and strategies in the field of tissue regeneration. One key observation is the critical role that membranes play in guided reconstruction; they serve as a barrier, preventing the entry of non-ossifying cells, thereby promoting the successful growth and regeneration of bone and tissue. By reviewing the existing literature on biomaterials, membranes, and scaffold manufacturing technologies, this paper illustrates the vast potential for innovation and growth within the field of dental therapeutic interventions, particularly in guided tissue and bone regeneration.

Alveolar ridge preservation: Complications and cost-effectiveness

Alveolar ridge preservation is routinely indicated in clinical practice with the purpose of attenuating postextraction ridge atrophy. Over the past two decades numerous clinical studies and reviews on this topic have populated the literature. In recent years the focus has primarily been on analyzing efficacy outcomes pertaining to postextraction dimensional changes, whereas other relevant facets of alveolar ridge preservation therapy have remained unexplored. With this premise, we carried out a comprehensive evidence-based assessment of the complications associated with different modalities of alveolar ridge preservation and modeled the cost-effectiveness of different therapeutic modalities as a function of changes in ridge width and height. We conclude that, among allogeneic and xenogeneic bone graft materials, increased expenditure does not translate into increased effectiveness of alveolar ridge preservation therapy. On the other hand, a significant association between expenditure on a barrier membrane and reduced horizontal and vertical ridge resorption was observed, though only to a certain degree, beyond which the return on investment was significantly diminished.

Incorporating Moldable Demineralized Dentin Matrix into Treatment for a Jaw Cyst

The enucleation procedure is a standard treatment for jaw cysts; however, it often results in post-operative bony defects. These defects can lead to serious complications such as the risk of pathologic fracture and delayed wound healing, especially in the case of large cysts where there may be soft tissue dehiscence. Even in the case of smaller cysts, most cystic defects remain visible on postoperative radiographs and can be mistaken for cyst recurrence during follow-up periods. To avoid such complications, the use of bone graft materials should be considered. While autogenous bone is the most ideal graft material as it can be regenerated into functional bone, it has limitations due to the inevitable harvesting surgery. Many tissue engineering studies have been conducted to develop substitutes for autogenous bone. One such material is moldable-demineralized dentin matrix (M-DDM), which can aid in regeneration in cases of cystic defects. This case report highlights a patient who demonstrated the efficacy of M-DDM in bone healing for filling the cystic defect.

Effects of collagen membrane on bone level and periodontal status of adjacent tooth after third molar surgery: a randomized controlled trial

BACKGROUND

The periodontal status and distal bone level of the adjacent second molar can be negatively affected by the surgical extraction of an impacted lower third molar. Absorbable materials have some benefits, including enhancing primary wound coverage and promoting wound healing through isolation, clotting, wound stabilization and haemostasis. This study set out to compare primary and secondary healing and collagen-membrane-based primary healing after surgical removal of partially erupted impacted third molars (3Ms), evaluating the distal alveolar bone level (ABL) and periodontal status of the adjacent second molars (2Ms).

METHODS

Patients who met the inclusion criteria were randomized into three groups: secondary healing (n = 28), primary healing (n = 27) and membrane-based primary healing (n = 29). Digital panoramic radiographs were obtained preoperatively (T1) and three months postoperatively (T2). The distances between the cemento-enamel junctions and the alveolar bone crests on the distal aspects of the adjacent 2Ms were measured using calibrated radiograph measurement software. The pocket depth and plaque index measurements were performed preoperatively and three months postoperatively. The periodontal plaque index (PPI) scores were registered on the distal aspects of the 2Ms, and the mean values were used.

RESULTS

Three of the applied healing types positively affected periodontal pocket depth (PPD) and periodontal index values (p < 0.05). In terms of the ABL of the adjacent 2Ms, primary healing (p < 0.05) and membrane-based primary healing (p < 0.05) had superior results to secondary healing.

CONCLUSION

Membrane use is promising for the distal bone gain and periodontal status of the adjacent 2M.

TRIAL REGISTRATION

This clinical study was registered by the Australian New Zealand Clinical Trials Registry, with the trial number ACTRN12618001551280.

MgO Nanoparticles-Incorporated PCL/Gelatin-Derived Coaxial Electrospinning Nanocellulose Membranes for Periodontal Tissue Regeneration

Electrospinning technique has attracted considerable attention in fabrication of cellulose nanofibrils or nanocellulose membranes, in which polycaprolactone (PCL) could be used as a promising precursor to prepare various cellulose nanofibril membranes for periodontal tissue regeneration. Conventional bio-membranes and cellulose films used in guided tissue regeneration (GTR) can prevent the downgrowth of epithelial cells, fibroblasts, and connective tissue in the area of tooth root but have limitations related to osteogenic and antimicrobial properties. Cellulose nanofibrils can be used as an ideal drug delivery material to encapsulate and carry some drugs. In this study, magnesium oxide (MgO) nanoparticles-incorporated PCL/gelatin core-shell nanocellulose periodontal membranes were fabricated using coaxial electrospinning technique, which was termed as Coaxial-MgO. The membranes using single-nozzle electrospinning technique, namely Blending-MgO and Blending-Blank, were used as control. The morphology and physicochemical property of these nanocellulose membranes were characterized by scanning electron microscopy (SEM), energy-dispersive spectrum of X-ray (EDS), transmission electron microscopy (TEM), contact angle, and thermogravimetric analysis (TGA). The results showed that the incorporation of MgO nanoparticles barely affected the morphology and mechanical property of nanocellulose membranes. Coaxial-MgO with core-shell fiber structure had better hydrophilic property and sustainable release of magnesium ion (Mg²⁺). CCK-8 cell proliferation and EdU staining demonstrated that Coaxial-MgO membranes showed better human periodontal ligament stem cells (hPDLSCs) proliferation rates compared with the other group due to its gelatin shell with great biocompatibility and hydrophilicity. SEM and immunofluorescence assay results illustrated that the Coaxial-MgO scaffold significantly enhanced hPDLSCs adhesion. In vitro osteogenic and antibacterial properties showed that Coaxial-MgO membrane enhanced alkaline phosphatase (ALP) activity, formation of mineralized nodules, osteogenic-related genes [ALP, collagen type 1 (COL1), runt-related transcription factor 2 (Runx2)], and high antibacterial properties toward Escherichia coli (E. coli) and Actinobacillus actinomycetemcomitans (A. a) when compared with controls. Our findings suggested that MgO nanoparticles-incorporated coaxial electrospinning PCL-derived nanocellulose periodontal membranes might have great prospects for periodontal tissue regeneration.

A multifunctional electrowritten bi-layered scaffold for guided bone regeneration

The guided bone regeneration (GBR) concept has been extensively utilized to treat maxillofacial bone defects in clinical practice. However, the repair efficacy of currently available GBR membranes is often compromised by their limited bone regeneration potential and deficient antibacterial activity. In this study, inspired by the bi-layered structure design of the commonly used Bio-Gide^Ⓡmembrane, we designed and fabricated a new kind of multifunctional bi-layered "GBR scaffold" combining solution electrospinning writing (SEW) and solution electrospinning (SES) techniques using a single SEW printer. Copper-loaded mesoporous silica nanoparticles (Cu@MSNs) were incorporated into the poly(lactic-co-glycolic acid)/gelatin (PLGA/Gel, denoted as PG) fiber matrix to construct a composite PG-Cu@MSNs fibrous scaffold. The obtained GBR scaffold consisted of a loose and porous SEW layer to support and facilitate bone ingrowth, and a dense and compact SES layer to resist non-osteoblast interference. The resulting enhanced mechanical properties, coordinated degradation profile, and facile preparation procedure imparted the composite scaffold with good clinical feasibility. In vitro biological experiments indicate that the PG-Cu@MSNs composite scaffold exhibited favorable osteogenic and antibacterial properties. Furthermore, an in vivo rat periodontal defect model further confirmed the promising bone regeneration efficacy of the PG-Cu@MSNs scaffold. In conclusion, the developed electrowritten Cu@MSNs-incorporated bi-layered scaffold with hierarchical architecture and concurrent osteogenic and antibacterial functions may hold great potential for application in GBR.

Influence of biodegradable polymer membrane on new bone formation and biodegradation of biphasic bone substitutes: an animal mandibular defect model study

Purpose

The purpose of this study was to evaluate the influence of biodegradable polycaprolactone membrane on new bone formation and the biodegradation of biphasic alloplastic bone substitutes using animal models.

Materials and methods

In this study, bony defect was formed at the canine mandible of 8 mm in diameter, and the defects were filled with Osteon II. The experimental groups were covered with Osteoguide as barrier membrane, and the control groups were closed without membrane coverage. The proportion of new bone and residual bone graft material was measured histologically and histomorphometrically at postoperative 4 and 8 weeks.

Results

At 4 weeks, the new bone proportion was similar between the groups. The proportion of remaining graft volume was 27.58 ± 6.26 and 20.01 ± 4.68% on control and experimental groups, respectively (P < 0.05). There was no significant difference between the two groups in new bone formation and the amount of residual bone graft material at 8 weeks.

Conclusion

The biopolymer membrane contributes to early biodegradation of biphasic bone substitutes in the jaw defect but it does not affect the bone formation capacity of the bone graft.

The Release of the Bromodomain Ligand N,N-Dimethylacetamide Adds Bioactivity to a Resorbable Guided Bone Regeneration Membrane in a Rabbit Calvarial Defect Model

N,N-Dimethylacetamide (DMA) is FDA approved as an excipient and is used as drug-delivery vehicle. Due to its amphipathic nature and diverse bioactivities, it appears to be a good combination of biodegradable poly-lactide-co-glycolide (PLGA)-based guided bone regeneration membranes. Here we show that the solvent DMA can be loaded to PLGA membranes by different regimes, leading to distinct release profiles, and enhancing the bone regeneration in vivo. Our results highlight the potential therapeutic benefits of DMA in guided bone regeneration procedures, in combination with biodegradable PLGA membranes.

N-Methyl Pyrrolidone (NMP) Alleviates Lipopolysaccharide (LPS)-Induced Inflammatory Injury in Articular Chondrocytes

Background

Studies on the chondrocyte inflammatory injury are very important for understanding the pathogenesis and clinical treatment of osteoarthritis (OA). Evidence suggests that N-methyl pyrrolidone (NMP) may be used as an adjuvant therapy alongside established methods of OA treatment. This study investigated the effect of NMP on chondrocyte inflammatory injury and explored the underlying molecular mechanism.

Material/Methods

To mimic the inflammatory injury in vitro, the articular chondrocyte line ATDC5 was simulated with lipopolysaccharide (LPS). ATDC5 cells were treated with various concentrations of NMP (0, 5, and 10 nM). Cell viability was measured using CCK-8 assay; cell apoptosis was detected using FCM; related protein and mRNA expressions were determined using Western blot assay and qRT-PCR assay; and inflammatory factors (tumor necrosis factor (TNF)-α, interleukin (IL)-1β, IL-6, and IL-8) productions were measured by performing ELISA assay.

Results

The results showed that LPS simulation repressed ATDC5 cell viability, prompted cell apoptosis, and enhanced the secretion of inflammatory factors. NMP treatment reduced inflammatory injury induced by LPS in a dose-dependent manner. Furthermore, NMP inhibited the activation of JNK and p38 pathways. In addition, inhibition of NF-κB activation was observed following NMP treatment.

Conclusions

NMP prevents inflammatory reaction of articular chondrocytes via repressing the MAPK/NF-κB pathway. Our findings provide a promising therapeutic agent for OA treatment.

How effective is collagen resorbable membrane placement after partially impacted mandibular third molar surgery on postoperative morbidity? A prospective randomized comparative study

Background

Collagen membranes have some benefits include promoting wound healing through isolation, clot stabilization, wound stability, and hemostasis, enhancing primary wound coverage through its chemotactic ability to attract fibroblasts, and augmenting flap thickness by providing a collagenous scaffold. The purpose of this study was to compare primary and secondary healing and collagen membrane-based primary healing after surgical removal of partial impacted mandibular third molars, evaluating the incidence of postoperative complications and analyzing the swelling, mouth opening, and pain.

Methods

This was a prospective, randomized controlled study. Patients were randomly assigned to three groups: the SC (Secondary closure) group, the PC (Primary closure) group, and the MBPC (membrane based primary closure) group. Data were collected on pain, mouth opening, swelling, and complications experienced by the patients.

Results

There was no statistically significant difference between the groups for the pain (p > 0.05), relatively. The swelling recorded on postoperative days 2 and 7 was lower in the SC group than in the PC (p = 0.046 and 0.00) and in MBPC (p = 0.005 and 0.002) groups, respectively. Mouth opening showed a statistically significant difference between the three groups at day 2 (p = 0.00). Wound dehiscence was shown in 6 patients in the PC (20%) group and 2 patients in the MBPC (6.7%) group. Dry socket was observed 3 patients in the SC group (10%), 2 patients in the PC group (6.7%), and no dry socket in the MBPC group. No cases of infection or postoperative bleeding were encountered.

Conclusions

The secondary closure provides a marked advantage over the primary closure in terms of swelling and mouth opening. However, the absence of alveolitis in the primary closure using the collagen membrane and minimal wound dehiscence, suggests that membrane use may support primary healing in terms of wound healing.

Release kinetics and mitogenic capacity of collagen barrier membranes supplemented with secretome of activated platelets - the in vitro response of fibroblasts of the periodontal ligament and the gingiva

Background

Platelet preparations can stimulate the healing process and have mitogenic properties. We hypothesized that collagen barrier membranes (CBM), clinically used in guided bone regeneration and guided tissue regeneration, can serve as carriers for platelet secretome.

Methods

Secretome was generated from washed platelets and unwashed platelets (washed/unwashed PSEC) and lyophilized onto CBM. Overall appearance of CBM was evaluated by scanning electron microscopy. The impact of PSEC on cell attachment was measured based on fluorescence microscopy with DiI-labeled cells. To assess the release kinetics, supernatants of CBM were collected and medium was replaced at hour 1–48. The mitogenic effect was evaluated with periodontal fibroblasts. Furthermore, the release of total protein, platelet-derived growth factor (PDGF)-BB, and transforming growth factor (TGF) β1 was measured.

Results

CBM overall appearance and cell attachment was not modulated by PSEC. Supernatants taken after one hour induced a mitogenic response in fibroblasts and showed the highest levels of total protein, TGFβ1 and PDGF-BB. These effects decreased rapidly in subsequent supernatants. While supernatants of CBM loaded with unwashed PSEC induced a stronger mitogenic response than supernatants of CBM loaded with washed PSEC this difference between the PSEC preparations was not observed when cells were seeded on 48–hours-washed CBM.

Conclusions

CBM release platelet-derived factors in continuously declining release kinetics.

Influence of N-methyl pyrrolidone on the activity of the pulp-dentine complex and bone integrity during osteoporosis

AIM

To analyse the effect of systemic application of N-methyl pyrrolidone (NMP) on the pulp-dentine complex and on the jawbone of ovariectomized rats.

METHOD

Female Sprague Dawley rats were randomly divided into a Sham-operated group (Sham n = 6) and an oestrogen depletion by ovariectomy (OVX n = 12) group. In 6 of the ovariectomized animals, N-methyl pyrrolidone (NMP) in phosphate-buffered saline (PBS) was administered systemically weekly by intraperitoneal injection (i.p.); the other 6 were injected with PBS (Veh). After 15 weeks of injections, the jaw bones were collected and pulps extracted from the incisors teeth. Histology was used to determine pre-dentine thickness in teeth and radiography to determine alveolar bone mass. Immunohistological staining and RT-PCR were performed to verify the presence and localization of the odontoblast-specific dentine sialoprotein and to quantify its expression in the dentine-pulp complex. Mandibular cortical width and mandibular height were evaluated by means of X-ray analysis. Statistical analysis was performed with analysis of variance (anova).

RESULTS

Both pre-dentine (P = 0.029) and alveolar bone structures (P = 0.049) were significantly reduced due to oestrogen deficiency in OVX Veh and OVX. NMP treatment normalized these parameters to the Sham level. DSPP expression in OVX NMP animals was significantly higher (P = 0.046) than in OVX Veh. X-ray analysis confirmed that ovariectomy significantly reduced the mandibular cortical width in the OVX Veh group compared to the Sham Veh and OVX NMP (P = 0.020).

CONCLUSION

N-methyl pyrrolidone (NMP) had a remarkable anti-osteoporotic ability preserving activity in the pulp-dentine complex and preventing jawbone loss. These effects make NMP a promising candidate for the preservation of the activity of the pulp-dentine complex and jawbone thickness in post-menopausal females.

Biodegradable Polymer Membranes Applied in Guided Bone/Tissue Regeneration: A Review

Polymer membranes have been widely used in guided tissue regeneration (GTR) and guided bone regeneration (GBR). In this review, various commercially available membranes are described. Much attention is paid to the recent development of biodegradable polymers applied in GTR and GBR, and the important issues of biodegradable polymeric membranes, including their classification, latest experimental research and clinical applications, as well as their main challenges are addressed. Herein, natural polymers, synthetic polymers and their blends are all introduced. Pure polymer membranes are biodegradable and biocompatible, but they lack special properties such as antibacterial properties, osteoconductivity, and thus polymer membranes loaded with functional materials such as antibacterial agents and growth factors show many more advantages and have also been introduced in this review. Despite there still being complaints about polymer membranes, such as their low mechanical properties, uncontrollable degradation speed and some other drawbacks, these problems will undoubtedly be conquered and biodegradable polymers will have more applications in GTR and GBR.

In vivo behaviour of a biodegradable poly(trimethylene carbonate) barrier membrane: a histological study in rats

The aim of the present study was to evaluate the response of surrounding tissues to newly developed poly(trimethylene carbonate) (PTMC) membranes. Furthermore, the tissue formation beneath and the space maintaining properties of the PTMC membrane were evaluated. Results were compared with a collagen membrane (Geistlich BioGide), which served as control. Single-sided standardized 5.0 mm circular bicortical defects were created in the mandibular angle of rats. Defects were covered with either the PTMC membrane or a collagen membrane. After 2, 4 and 12 weeks rats were sacrificed and histology was performed. The PTMC membranes induced a mild tissue reaction corresponding to a normal foreign body reaction. The PTMC membranes showed minimal cellular capsule formation and showed signs of a surface erosion process. Bone tissue formed beneath the PTMC membranes comparable to that beneath the collagen membranes. The space maintaining properties of the PTMC membranes were superior to those of the collagen membrane. Newly developed PTMC membranes can be used with success as barrier membranes in critical size rat mandibular defects.

Treatment of intrabony defects after impacted mandibular third molar removal with bioabsorbable and non-resorbable membranes

BACKGROUND

Mandibular second molar (M2) periodontal defects after third molar (M3) removal in high-risk patients are a clinical dilemma for clinicians. This study compares the healing of periodontal intrabony defects at distal surfaces of mandibular M2s using bioabsorbable and non-resorbable membranes.

METHODS

Eleven patients with bilateral probing depths (PDs) ≥6 mm distal to mandibular M2s and intrabony defects ≥3 mm, related to the total impaction of M3s, were treated with M3 extraction and covering of the surgical bone defect with a bioabsorbable collagen barrier on one side and a non-resorbable expanded polytetrafluoroethylene (ePTFE) barrier contralaterally. The PD, clinical attachment level (CAL), M2 mobility, and furcation class probing were evaluated preoperatively and 3, 6, and 9 months postoperatively. Intraoral periapical radiographs were taken immediately preoperatively and 3 and 9 months postoperatively.

RESULTS

Both treatment modalities were successful. At 9 months, the mean PD reduction was 5.2 ± 3.9 mm for bioabsorbable sites and 5.5 ± 3.0 mm for non-resorbable sites; the CAL gain was 5.9 ± 3.3 mm and 5.5 ± 3.4 mm, respectively. The outcome difference between the two sites for PD and CAL did not differ statistically (P >0.05) at any assessment time.

CONCLUSION

Bioabsorbable collagen membranes in guided tissue regeneration treatment of intrabony defects distal to the mandibular M2 obtained the same marked PD reductions and CAL gains as non-resorbable ePTFE membranes after M3 extraction.