Native vs. ribosome-crosslinked collagen membranes for periodontal regeneration: A randomized clinical trial.

AIM: To evaluate whether the ribosome-crosslinked collagen membrane (RCCM) is non-inferior to the natural collagen membrane (NCM) used in regeneration surgery in terms of clinical attachment level (CAL) gain at 6 months. METHODS: Eighty patients diagnosed as generalized periodontitis presenting with isolated infrabony defect (≥4 mm deep) were enrolled and randomized to receive regenerative surgery, either with NCM or RCCM, both combined with deproteinized bovine bone mineral (DBBM). CAL, pocket probing depth (PPD), and gingival recession (GR) were recorded at baseline, 3, and 6 months postoperatively. Periapical radiographs were taken at baseline, immediately, and 6 months after surgery. Early wound healing index (EHI) and patients' responses were recorded at 2 weeks postoperatively. RESULTS: At 6 months post-surgery, the mean CAL gain was 3.1 ± 1.5 mm in the NCM group and 2.9 ± 1.5 mm in the RCCM group, while the mean PPD was 4.3 ± 1.1 mm in the NCM group and 4.2 ± 1.0 mm in the RCCM group. Both groups demonstrated a statistically significant improvement from the baseline (p < .01). RCCM was non-inferior to NCM concerning the primary outcome (CAL gain at 6 months). The GR at 6 months postoperatively was 1.3 ± 1.2 and 1.2 ± 1.1 mm, which showed no difference compared with baseline. At 6 months follow-up, the radiographic linear bone fill (RLBF) was 6.5 ± 2.8 and 5.5 ± 2.6 mm (p > .05), while the bone fill percentage (BF%) was 102.3 ± 53.5% and 92.3 ± 40.1% (p > .05), in the NCM and RCCM groups, respectively. There was no significant difference in EHI and postoperative responses between two groups. CONCLUSION: RCCM + DBBM resulted in no-inferior clinical and radiographic outcomes to NCM + DBBM for the treatment of isolated infrabony defect in 6 months.

The efficacy of reconstructive therapy in the surgical management of peri-implantitis: A 3-year follow-up of a randomized clinical trial.

AIM: To assess whether guided bone regeneration (GBR) treatment of peri-implantitis-related bony defects could improve healing compared to open flap debridement (OFD) at 36 months. MATERIALS AND METHODS: In a multi-centre, randomized clinical trial, 32 individuals received OFD (control group [CG]) and 34 GBR treatment (test group [TG]). Radiographic defect fill (RDF), probing pocket depth (PPD), bleeding on probing (BOP) suppuration (SUP), mucosal recession (MREC) and patient-reported outcomes (PROs) were evaluated at 36 months. RESULTS: Fifty individuals attended a supportive peri-implant therapy program and completed the 36-month follow-up. GBR treatment resulted in an RDF of 2.13 ± 1.26 mm compared to 1.64 ± 1.54 mm following OFD (p = .18). No difference was found in PPD, BOP, SUP, REC or PROs between the groups. Successful treatment (no additional bone loss, PPD ≤ 5 mm, no BOP and no SUP) was achieved in 46.2% in TG and 20% in CG (p = .053). Treatment results obtained at 12 months were generally maintained up to 36 months. No significant changes were noticed between 12 and 36 months. CONCLUSIONS: At 36 months, treatment results obtained at 1 year were sustained following both GBR and OFD in patients attending supportive peri-implant therapy. GBR resulted in more RDF and higher composite treatment success rate than OFD (ClinicalTrials.gov Identifier [NCT02375750]).

Treatment of chronic and complex meniscal tears with arthroscopic meniscus repair augmented with collagen matrix wrapping: failure rate and functional outcomes.

PURPOSE: Meniscal wrapping is a fully arthroscopic technique that involves enhanced meniscal repair with a tissue-engineered collagen matrix wrapping. This study aims to investigate the feasibility of using the meniscal wrapping technique for the treatment of chronic or complex meniscal tears. The primary objective is to assess its failure rate. The secondary objectives are to analyse complication rate, functional outcomes and overall patient satisfaction. METHODS: This retrospective case series study included patients who sustained chronic and complex tears undergoing meniscal wrapping with autologous liquid bone marrow injection. Failure rate was considered if the patient underwent partial or complete meniscectomy or knee replacement during the follow-up, while other unexpected knee reoperations were considered as complications. Clinical outcomes were evaluated through the IKDC score, Tegner Activity Score and Short Assessment of Patient Satisfaction. RESULTS: Twenty-one patients were included (15 non-acute bucket-handle tears, three non-acute horizontal tears and three non-acute complex injuries). The failure rate was 9.5% at 33 months. The rate of other unplanned reoperations was 14.3%, but none of these complications were apparently directly related to the wrapping technique. The average postoperative IKDC was 73.3/100. No statistically significant difference was encountered between preinjury and postoperative Tegner Activity Score. The mean overall patient satisfaction was 88.3/100. CONCLUSIONS: Meniscal wrapping can be safely used as an adjunctive technique to meniscal repair in such difficult-to-treat cases to preserve the meniscus. The technique achieves a low failure rate and promising results of knee function, and patient satisfaction.

Novel Collagen Surgical Patches for Local Delivery of Multiple Drugs.

Effective control of post-operative inflammation after tissue repair remains a clinical challenge. A tissue repair patch that could appropriately integrate into the surrounding tissue and control inflammatory responses would improve tissue healing. A collagen-based hybrid tissue repair patch has been developed in this work for the local delivery of an anti-inflammatory drug. Dexamethasone (DEX) was encapsulated into PLGA microspheres and then co-electrocompacted into a collagen membrane. Using a simple process, multiple drugs can be loaded into and released from this hybrid composite material simultaneously, and the ratio between each drug is controllable. Anti-inflammatory DEX and the anti-epileptic phenytoin (PHT) were co-encapsulated and released to validate the dual drug delivery ability of this versatile composite material. Furthermore, the Young's modulus of this drug-loaded collagen patch was increased to 20 KPa using a biocompatible riboflavin (vitamin B2)-induced UV light cross-linking strategy. This versatile composite material has a wide range of potential applications which deserve exploration in further research.

Membrane barriers for guided bone regeneration: An overview of available biomaterials.

Dental implants revolutionized the treatment options for restoring form, function, and esthetics when one or more teeth are missing. At sites of insufficient bone, guided bone regeneration (GBR) is performed either prior to or in conjunction with implant placement to achieve a three-dimensional prosthetic-driven implant position. To date, GBR is well documented, widely used, and constitutes a predictable and successful approach for lateral and vertical bone augmentation of atrophic ridges. Evidence suggests that the use of barrier membranes maintains the major biological principles of GBR. Since the material used to construct barrier membranes ultimately dictates its characteristics and its ability to maintain the biological principles of GBR, several materials have been used over time. This review, summarizes the evolution of barrier membranes, focusing on the characteristics, advantages, and disadvantages of available occlusive barrier membranes and presents results of updated meta-analyses focusing on the effects of these membranes on the overall outcome.

Bacterial exclusion and wound healing potential of horizontal platelet-rich fibrin (H-PRF) membranes when compared to 2 commercially available collagen membranes.

OBJECTIVES: The aim of the present study was to compare the barrier function during bacterial invasion and wound healing properties of 3 commonly used membranes including horizontal platelet-rich fibrin (H-PRF) against two commercially available resorbable collagen membranes. MATERIALS AND METHODS: H-PRF membranes were prepared by collecting venous blood from 3 healthy volunteers using a 700 g for 8-min centrifugation protocol followed by compression into membranes. To evaluate their barrier function, 3 groups (H-PRF membrane, collagen membrane A (Bio-Gide, Geistlich), collagen membrane B (Megreen, Shanxi Ruisheng Biotechnology Co) were placed between an inner chamber and outer chamber and inoculated with S. aureus. At 2 h, 24 h, and 48 h post-inoculation, cultures from the inner and outer chambers were assessed for bacterial CFUs. Then, scanning electron microscope (SEM) was utilized to visualized the morphological destruction by bacteria of the inner and outer surfaces of the membranes. To assess the wound healing properties of each membrane, leachates from each group were applied to human gingival fibroblasts (HGF) and a scratch assay was performed at 24 h and 48 h. RESULTS: S. aureus showed a minimal bacterial attachment or invasion rate through either collagen membranes at 2 h post-inoculation, yet over time demonstrated rapid degradation, especially on the rougher surface. While PRF demonstrated higher number of CFUs after 2 h, no significant penetration/degradation of the H-PRF membranes was observed at 24 h and 48 h in the H-PRF group. Both collagen membranes demonstrated significant morphological changes 48 h post-bacterial innoculation, while minimal obvious morphological changes were observed in the H-PRF group. The wound healing assay also demonstrated significantly better wound closure rates in the H-PRF group. CONCLUSION: H-PRF membranes exhibited better barrier function towards S. aureus over 2 days of innoculation and better wound healing ability when compared to two commercially available collagen membranes. CLINICAL RELEVANCE: This study provides further evidence for the application of H-PRF membranes during guided bone regeneration by minimizing bacterial invasion. Furthermore, H-PRF membranes have significantly better ability to promote wound healing.

The impact of membrane perforation and L-PRF for vertical ridge augmentation with a xenogeneic block graft: an experimental study in a canine model.

OBJECTIVES: This study evaluated clinically and histologically the efficacy of modified perforated collagen membrane (PCM) and/or leukocyte- and platelet-rich fibrin (L-PRF) in combination with xenogeneic block bone graft in the vertical alveolar ridge augmentation. MATERIALS AND METHODS: Six adult mongrel dogs were enrolled in this randomized blinded study. After defect preparation, xenogeneic screw-fixed block graft was covered by an occlusive collagen membrane in group 1 that represented the control group (Block + CM). In group 2, L-PRF membrane was added first before top coverage by occlusive collagen membrane (Block + L-PRF + CM). Groups 3 (Block + PCM) and 4 (Block + L-PRF + PCM) were identical to the first two groups except that the occlusive collagen membrane was replaced by a perforated one. Following a healing period of 2 months, the dogs were submitted to the surgical reentry phase for clinical and histological evaluation. RESULTS: Clinically, no significant differences were found among all groups regarding vertical and horizontal ridge dimensions (p = 0.155, 0.492, respectively). Histomorphometric analysis revealed that the percentage of the total bone area and mature bone was significantly higher in group 4 (69.36 ± 2.72, 33.11 ± 5.18) compared to the control group (59.17 ± 4.27, 21.94 ± 2.86) (p = 0. 027, p = 0.029). CONCLUSION: The use of xenogenic block grafts in combination with a double-layered perforated collagen L-PRF membrane in vertical ridge augmentation appeared to improve the inductive power of this challenging defect type. CLINICAL RELEVANCE: Size and number of perforations may affect the mechanical and handling properties of the membrane.

Optimizing the biodegradability and osteogenesis of biogenic collagen membrane via fluoride-modified polymer-induced liquid precursor process.

Biogenic collagen membranes (BCM) have been widely used in guided bone regeneration (GBR) owing to their biodegradability during tissue integration. However, their relatively high degradation rate and lack of pro-osteogenic properties limit their clinical outcomes. It is of great importance to endow BCM with tailored degradation as well as pro-osteogenic properties. In this study, a fluoride-modified polymer-induced liquid precursor (PILP) based biomineralization strategy was used to convert the collagen membrane from an organic phase to an apatite-based inorganic phase, thus achieving enhanced anti-degradation performance as well as osteogenesis. As a result, three phases of collagen membranes were prepared. The original BCM in the organic phase induced the mildest inflammatory response and was mostly degraded after 4 weeks. The organic-inorganic mixture phase of the collagen membrane evoked a prominent inflammatory response owing to the fluoride-containing amorphous calcium phosphate (F-ACP) nanoparticles, resulting in active angiogenesis and fibrous encapsulation, whereas the inorganic phase induced a mild inflammatory response and degraded the least owing to the transition of F-ACP particles into calcium phosphate with high crystallinity. Effective control of ACP is key to building novel apatite-based barrier membranes. The current results may pave the way for the development of advanced apatite-based membranes with enhanced barrier performances.

Meniscus repair via collagen matrix wrapping and bone marrow injection: clinical and biomolecular study.

PURPOSE: The functional outcomes of arthroscopic matrix-based meniscus repair (AMMR) in patients two and five years after the treatment clearly show that the use of the collagen matrix and bone marrow aspirate creates favorable biological conditions for meniscus healing. This study not only provides ten follow-up results but also investigates biomolecular mechanisms governing the regenerative process. METHODS: Case series was based on data collected from patients who underwent AMMR procedure, starting with preoperatively through two-year and five-year till ten-year follow-up. The outcomes are presented as IKDC and the Lysholm subjective scores as well as the imaging results. Biomolecular investigation of the membranes utilized in the AMMR procedure include DNA content analysis, cell viability and proliferation study of bone marrow and bone marrow concentrate-derived cells, and cytokine array performed on monocytes cultured on the membranes. CONCLUSION: Data collected from patients who underwent AMMR procedure, starting with pre-operatively through two year and five year till ten year follow-up, indicate the possibility for long-term, stable meniscus preservation. Outcomes are manifested with a visible improvement of the IKDC and the Lysholm subjective scores as well as in the imaging results. The type of the meniscal tear or complexity of the knee injury (isolated AMMR vs. AMMR + ACL) did not affect the clinical outcomes. The study highlighted the role of the membrane in facilitating cell adhesion and proliferation. Additionally, several cytokines were selected as potentially crucial products of the membrane vs. monocyte interactions, driving the tissue regeneration and remodeling. Interestingly, thresholds of what constitutes a safe and well-decellularized membrane according to relevant literature have been significantly breached, but ultimately did not elicit detrimental side effects.

Analyses of the Cellular Interactions between the Ossification of Collagen-Based Barrier Membranes and the Underlying Bone Defects.

Barrier membranes are an essential tool in guided bone Regeneration (GBR), which have been widely presumed to have a bioactive effect that is beyond their occluding and space maintenance functionalities. A standardized calvaria implantation model was applied for 2, 8, and 16 weeks on Wistar rats to test the interactions between the barrier membrane and the underlying bone defects which were filled with bovine bone substitute materials (BSM). In an effort to understand the barrier membrane's bioactivity, deeper histochemical analyses, as well as the immunohistochemical detection of macrophage subtypes (M1/M2) and vascular endothelial cells, were conducted and combined with histomorphometric and statistical approaches. The native collagen-based membrane was found to have ossified due to its potentially osteoconductive and osteogenic properties, forming a "bony shield" overlying the bone defects. Histomorphometrical evaluation revealed the resorption of the membranes and their substitution with bone matrix. The numbers of both M1- and M2-macrophages were significantly higher within the membrane compartments compared to the underlying bone defects. Thereby, M2-macrophages significantly dominated the tissue reaction within the membrane compartments. Statistically, a correlation between M2-macropahges and bone regeneration was only found at 2 weeks post implantationem, while the pro-inflammatory limb of the immune response correlated with the two processes at 8 weeks. Altogether, this study elaborates on the increasingly described correlations between barrier membranes and the underlying bone regeneration, which sheds a light on the understanding of the immunomodulatory features of biomaterials.

Implant Placement Using the Bone Ring Technique With and Without Membrane Placement: A Preclinical 12-Month Study in Dogs.

The bone ring technique is applied for vertical augmentation, in which the dental implant and autogenous block bone graft are simultaneously inserted. We investigated the healing of bone around implants placed simultaneously using the bone ring technique with and without membrane placement after a 12-month healing period. Vertical bone defects were created on both sides of the mandible of Beagle dogs. Implants were inserted into the defects through bone rings and fixed with membrane screws as healing caps. The augmented sites on one side of the mandible were covered with a collagen membrane. Samples were harvested 12 months after implantation and assessed histologically and by microcomputed tomography analysis. All implants remained throughout the healing period; however, except for 1 implant, they showed lost caps and/or exposure to the oral cavity. The implants had contact with newly formed bone despite frequent bone resorption. The surrounding bone appeared mature. The medians of bone volume and percentages of total bone area and bone-to-implant contact within the bone ring were slightly higher in the group with membrane placement than in that without membrane placement. Nevertheless, none of the evaluated parameters were significantly affected by the membrane placement. In the present model, soft tissue complication was frequent, and the membrane application did not reveal the effect at 12 months after implant placement using the bone ring technique. Sustained osseointegration and maturation of surrounding bone were observed in both groups after a 12-month healing period.

Physical, mechanical, and biological properties of collagen membranes for guided bone regeneration: a comparative in vitro study.

BACKGROUND: To provide a reference for clinical selection of collagen membranes by analyzing the properties of three kinds of collagen membranes widely used in clinics: Bio-Gide membrane from porcine dermis (PD), Heal-All membrane from bovine dermis (BD), and Lyoplant membrane from bovine pericardium (BP). METHODS: The barrier function of three kinds of collagen membranes were evaluated by testing the surface morphology, mechanical properties, hydrophilicity, and degradation rate of collagen membranes in collagenase and artificial saliva. In addition, the bioactivity of each collagen membrane as well as the proliferation and osteogenesis of MC3T3-E1 cells were evaluated. Mass spectrometry was also used to analyze the degradation products. RESULTS: The BP membrane had the highest tensile strength and Young's modulus as well as the largest water contact angle. The PD membrane exhibited the highest elongation at break, the smallest water contact angle, and the lowest degradation weight loss. The BD membrane had the highest degradation weight loss, the highest number of proteins in its degradation product, the strongest effect on the proliferation of MC3T3-E1 cells, and the highest expression level of osteogenic genes. CONCLUSIONS: The PD membrane is the best choice for shaping and maintenance time, while the BD membrane is good for osteogenesis, and the BP membrane is suitable for spatial maintenance. To meet the clinical requirements of guided bone regeneration, using two different kinds of collagen membranes concurrently to exert their respective advantages is an option worth considering.

[Role of collagen membrane in modified guided bone regeneration surgery using buccal punch flap approach: A retrospective and radiographical cohort study].

OBJECTIVE: To investigate whether the placement of absorbable collagen membrane increase the stability of alveolar ridge contour after guided bone regeneration (GBR) using buccal punch flap. METHODS: From June 2019 to June 2023, patients who underwent GBR using buccal punch flap simultaneously with a single implant placement in posterior region (from first premolar to second molar) were divided into coverage group, in which particular bone graft was covered by collagen membrane and non-coverage group. Cone beam CT (CBCT) was taken before surgery (T0), immediately after surgery (T1), and 3-7 months after surgery (T2), and the thickness of the buccal bone plate at different levels (0, 2, 4, and 6 mm) below the smooth-rough interface of the implant (BBT-0, -2, -4, -6) was mea-sured after superimposition of CBCT models using Mimics software. RESULTS: A total of 29 patients, including 15 patients in coverage group and 14 patients in non-coverage group, were investigated in this study. At T0, T1, and T2, there was no significant difference in BBT between the two groups (P>0.05). At T1, BBT-0 was (2.50±0.90) mm in the coverage group and (2.97±1.28) mm in the non-coverage group, with corresponding BBT-2 of (3.65±1.08) mm and (3.58±1.26) mm, respectively. At T2, BBT-0 was (1.22±0.55) mm in the coverage group and (1.70±0.97) mm in the non-coverage group, with corresponding BBT-2 of (2.32±0.94) mm and (2.57±1.26) mm, respectively. From T1 to T2, there were no statistically significant differences in the absolute values [(0.47±0.54)-(1.33±0.75) mm] and percentages [(10.04%±24.81%)-(48.43%±18.32%)] of BBT change between the two groups. The thickness of new bone formation in the buccal bone plate from T0 to T2 ranged from (1.27±1.09) mm to (2.75±2.15) mm with no statistical difference between the two groups at all levels. CONCLUSION: In the short term, the GBR using buccal punch flap with or without collagen membrane coverage can effectively repair the buccal implant bone defect. But collagen membrane coverage showed no additional benefit on alveolar ridge contour stability compared with non-membrane coverage.

Clinical observation of Porcine Collagen Membrane + artificial Bovine Bone Granules Guided tissue regeneration combined with Autologous CGF in the treatment of severe periodontitis bone defect.

Objective: To investigate and analyze the clinical observation of porcine collagen membrane + artificial bovine bone granules guided tissue regeneration (GTR) combined with autologous concentration of growth factors (CGF) in the treatment of severe periodontitis bone defect. Methods: A total of 94 patients with severe periodontitis bone defects admitted to Shanxi Bethune Hospital from January 2019 to January 2022 were included. They were divided into two groups by simple randomization method. Patients in the control group were treated with porcine collagen membrane + artificial bovine bone granules GTR, while those in the observation group were treated with autologous CGF on the basis of the control group. Before and after treatment, periodontal clinical indicators [sulcus bleeding index (SBI), gingival retreat index (GR), probing depth (PD), clinical attachment loss (CAL), alveolar bone height (AH)] and bone resorption markers [Osteoprotegerin (OPG), bone gla protein (BGP), Type-1 collagen N-terminal peptide (NTX)] were compared between the two groups, and the incidence of postoperative complications in the two groups was recorded. Results: The total efficacy of observation group was significantly higher than that of control group (p<0.05). Three months after surgery, the observation group had lower levels of SBI, PD, CAL and NTX while higher levels of GR, AH, OPG and BGP than the control group (p<0.05). There was no significant difference in complication rate between the two groups (p>0.05). Conclusion: Porcine collagen membrane + artificial bovine bone granules GTR combined with autologous CGF boasts various benefits in the treatment of severe periodontitis bone defects, such as improvement of clinical outcomes, amelioration of periodontal tissue and inhibition of bone resorption.

Effect of collagen membrane fixation on ridge volume stability and new bone formation following guided bone regeneration.

AIM: To test the effect of membrane fixation on ridge volume stability and new bone formation using guided bone regeneration. MATERIALS AND METHODS: In eight beagle dogs, after bilateral extraction of the maxillary pre-molars, a box-shaped defect was created on each side. All defect sites were augmented with a particulate bone substitute material, covered with either one of two non-cross-linked collagen membranes (CM1 or CM2) with or without fixation (-F or -UF). Samples were collected after 8 weeks. Histomorphometric and micro-computed tomography analyses were performed. RESULTS: Membrane fixation made no significant difference to the total augmented volume for both membranes (p > .05). Histological data indicated that at the ridge crest the augmented tissue width amounted to 2.4 ± 0.4 mm in the group CM1-F and 2.4 ± 0.5 mm in the group CM1-UF, with no significant difference between the groups. Conversely, in CM2-F the augmented tissue width was significantly larger than in CM2-UF (2.3 ± 0.1 vs. 1.57 ± 0.27, p < .05). CONCLUSIONS: Membrane fixation in contained defects failed to improve ridge volume stability regardless of the membrane type. However, it may enhance the width of the augmented ridge at the coronal portion depending on the type of membrane.

Membrane fixation enhances guided bone regeneration in standardized calvarial defects: A pre-clinical study.

AIM: To determine whether collagen membrane (CM) fixation enhances guided bone regeneration in standardized defects. MATERIALS AND METHODS: Four 8-mm-diameter defects were surgically made in eight rabbit calvaria, and randomly allocated into four groups: control (empty), unfixed-CM, fixed-CM, and unfixed-CM with bone graft (BG + CM) (positive control). After 1- and 4-week healing periods, the animals were sacrificed and quantitative reverse transcription polymerase chain reaction, micro-computed tomography, and histological outcomes were assessed. RESULTS: At week 1, the expression levels of BMP-2, FGF-2, VEGF, and osteocalcin were significantly higher in the fixed-CM group than in the unfixed-CM and control groups (p < .05). Conversely, cathepsin-K was significantly expressed in the unfixed-CM group. No significant differences in expression markers were observed between the fixed-CM and BG + CM groups (p > .05). At week 4, new bone formation was significantly higher in the fixed-CM group than the unfixed-CM and control groups (p < .05), but similar to the BG + CM group (p > .05). CONCLUSIONS: CM fixation enhances the expression of osteogenic factors similar to BG + CM, leading to significantly more new bone formation. This suggests that the osteogenic potential is greater when membranes are fixed, thereby limiting the necessity of membrane-supporting materials to enhance bone formation.

Comparative analysis of lateral maxillary sinus augmentation with a xenogeneic bone substitute material in combination with piezosurgical preparation and bony wall repositioning or rotary instrumentation and membrane coverage: a prospective randomized clinical and histological study.

OBJECTIVES: The present randomized controlled clinical study aimed to investigate if, in lateral maxillary sinus augmentation, the repositioned bony wall or the application of a collagen membrane results in more preferable new hard tissue formation. MATERIALS AND METHODS: Forty patients were divided into two study groups. Both groups received a xenogeneic bone substitute material (BSM) during lateral sinus augmentation. In the bony wall group (BW), following piezosurgery, the retrieved bony wall was repositioned. In the collagen membrane group (CM), following rotary instrument preparation, collagen membrane coverage was applied. After 6 months, biopsies were taken to histologically analyze the percentage of BSM, connective tissue (CT), and newly formed bone (NFB) following both approaches. RESULTS: Forty implants were placed and 29 harvested biopsies could be evaluated. Duration of surgery, membrane perforations, and VAS were detected. Histomorphometrical analysis revealed comparable amounts of all analyzed parameters in both groups in descending order: CT (BW: 39.2 ± 9%, CM: 37,9 ± 8.5%) > BSM (BW: 32.9 ± 6.3%, CM: 31.8 ± 8.8%) > NB (BW: 27.8 ± 11.2%, CM: 30.3 ± 4.5%). CONCLUSIONS: The results of the present study show that the closure of the access window by means of the retrieved bony wall or a native collagen membrane led to comparable bone augmentation results. CLINICAL TRIAL: clinicaltrials.gov NCT04811768. CLINICAL RELEVANCE: Lateral maxillary sinus augmentation with the application of a xenogeneic BSM in combination with a native collagen membrane for bony window coverage represents a reliable method for surgical reconstruction of the posterior maxilla. Piezosurgery with bony window repositioning delivers comparable outcomes without membrane coverage.

Soft tissue dimensional changes after alveolar ridge preservation using different sealing materials: a systematic review and network meta-analysis.

BACKGROUND: Alveolar ridge preservation (ARP) is a proactive treatment option aiming at attenuating post-extraction hard and soft tissue dimensional changes. A high number of different types of biomaterials have been utilized during ARP to seal the socket, but their effectiveness in terms of soft tissue outcomes has rarely been investigated and compared in the literature. OBJECTIVE: To evaluate the efficacy of different types of membranes and graft materials in terms of soft tissue outcomes (keratinized tissue width changes, vertical buccal height, and horizontal changes) after ARP, and to assign relative rankings based on their performance. MATERIALS AND METHODS: The manuscript represents the proceedings of a consensus conference of the Italian Society of Osseointegration (IAO). PUBMED (Medline), SCOPUS, Embase, and Cochrane Oral Health's Information Specialist were utilized to conduct the search up to 06 April 2021. English language restrictions were placed and no limitations were set on publication date. Randomized controlled trials that report ARP procedures using different sealing materials, assessing soft tissue as a primary or secondary outcome, with at least 6-week follow-up were included. Network meta-analysis (NMA) was performed using mean, standard deviation, sample size, bias, and follow-up duration for all included studies. Network geometry, contribution plots, inconsistency plots, predictive and confidence interval plots, SUCRA (surface under the cumulative ranking curve) rankings, and multidimensional (MDS) ranking plots were constructed. RESULTS: A total of 11 studies were included for NMA. Overall, the level of bias for included studies was moderate. Crosslinked collagen membranes (SUCRA rank 81.8%) performed best in vertical buccal height (VBH), autogenous soft tissue grafts (SUCRA rank 89.1%) in horizontal width change (HWch), and control (SUCRA rank 85.8%) in keratinized mucosa thickness (KMT). CONCLUSIONS: NMA confirmed that the use of crosslinked collagen membranes and autogenous soft tissue grafts represented the best choices for sealing sockets during ARP in terms of minimizing post-extraction soft tissue dimensional shrinkage. CLINICAL RELEVANCE: Grafting materials demonstrated statistically significantly better performances in terms of soft tissue thickness and vertical buccal height changes, when covered with crosslinked collagen membranes. Instead, soft tissue grafts performed better in horizontal width changes. Non-crosslinked membranes and other materials or combinations presented slightly inferior outcomes.

Continued root development of immature permanent teeth after regenerative endodontics with or without a collagen membrane: A randomized, controlled clinical trial.

BACKGROUND: Recent studies evaluated the efficacy of a collagen membrane (Bio-Gide) to promote root development in regenerative endodontics (REPs). However, the influence of etiology and tooth type on the results was not assessed. AIMS: To evaluate the quantitative and qualitative effect of a collagen membrane (Bio-Gide), with and without the effect of etiology and tooth type, in promoting root development in immature teeth after REPs. DESIGN: Eighty nonvital immature teeth were divided randomly into two groups (40 teeth in each group). REPs were performed with (experimental group) and without (control group) a collagen membrane. All teeth were subjected to regular clinical and radiographical follow-up. RESULTS: Seventy-six teeth were included in the final analyses. The average follow-up periods were 33.1 ± 21.8 months for the control group and 28.1± 18.6 months for the experimental group. Quantitative analysis of root development in the experimental group showed a greater increase in dentin wall thickness in the middle one-third of the root compared to the control group, with or without the effect of etiology and tooth type. Six types of root development were observed. There was no significant difference in the type of tooth development between the two groups. CONCLUSION: The use of a collagen membrane could promote an increase in dentin wall thickness in the middle one-third of the root, and it had no significant effect in terms of the type of subsequent root development.

Periosteum coverage versus collagen-membrane coverage in periodontally accelerated osteogenic orthodontics: a randomized controlled clinical trial in Class II and Class III malocclusions.

BACKGROUND: Periodontal accelerated osteogenic orthodontics (PAOO) is a widely-used clinical procedure that combines selective alveolar corticotomy, particulate bone grafting, and the application of orthodontic forces. Different modifications of PAOO such as collagen-membrane coverage can better benefit patients from preventing displacement of grafts. Due to its stability, collagen-membrane coverage gradually gained popularity and became a widely-used procedure in traditional PAOO technique. OBJECTIVES: To quantitatively investigate the radiographic changes of alveolar bone, periodontal soft tissue changes of the mandibular anterior teeth and postoperative complications in periosteum-covered techniques compared with traditional surgical technique in PAOO. METHODS: Orthodontic camouflage for dental Class II or decompensation for skeletal Class III malocclusions were included; Patients with bone defects on the buccal aspects of the anterior mandible regions confirmed by clinical and radiographic examination were randomly divided into the periosteum coverage group or traditional technique group for PAOO. Cone-beam computerized tomography (CBCT) scans were obtained before treatment (T0) and 1 week (T1) and 12 months (T2) after operation. The primary outcome variable was the vertical alveolar bone level (VBL), the secondary evaluation parameters included labial horizontal bone thickness at the midpoint of the middle third (MHBT) or apical third (AHBT) to the limit of the labial cortical surface during a 12-month follow-up. Postoperative sequelae were evaluated after 2 days and 7 days in both the groups. Periodontal parameters were analyzed at T0 and T2. RESULTS: Thirty-six adult subjects were eligible and recruited in the present study. Although experimental group exhibited more severe infection, no significant differences of the postoperative symptoms or periodontal parameters was found between the 2 groups (P > 0.05). All patients were examined respectively using CBCT at baseline (T0), postoperative 1 week (T1) and 12 months (T2). Both alveolar bone height and width increased from T0 to T1 (P < 0.001) and then reduced from T1 to T2 (P < 0.001) in both groups. However, significant bone augmentation was achieved in each group from T0 to T2 (P < 0.001). Furthermore, the vertical alveolar bone augmentation in the experimental group increased significantly than that in the traditional surgery (P < 0.05). CONCLUSIONS: Compared with traditional PAOO surgery, the periosteum-covered technique provides superior graft stabilization and satisfactory vertical bone augmentation in the labial mandibular anterior area.