Alveolar Ridge Preservation Research Articles

Clinical, radiographical and histological evaluation of alveolar ridge preservation with an autogenous tooth derived particulate graft in EDS class 3\u20134 defects

BackgroundThe shrinkage of alveolar bone dimensions after tooth extraction is a well-known issue. This clinical phenomenon poses a challenge for clinicians aiming at implant-prosthetic treatment. BonMaker® ATB is a novel autogenous bone grafting material, produced by the mechanical and chemical processing of natural teeth. This pilot case report aims at providing a clinical, radiographical, and histological evaluation of the safety and efficacy of Bonmaker ATB powder in the treatment of EDS class 3–4 postextraction sockets with alveolar ridge preservation.MethodsA total of 9 teeth were extracted from 5 patients. The extracted teeth were prepared immediately with the Bonmaker® device. The extraction sockets were filled up with ATB powder. Six months after extraction, standardized intraoral x-rays and CBCT scans were performed. Re-entry was performed under local anaesthesia. Core biopsies were harvested for histological analysis and implants were placed.ResultsHorizontal alveolar dimension loss occurred, even though ARP was performed, but the horizontal shrinkage was moderate. Vertical dimensions did not show loss of volume, but increased defect fill. Core biopsies showed ATB particles surrounded by newly formed bone and connective tissue. According to histomorphometric analysis, the harvested samples contained 56% of newly formed bone on average, and only a mean of 7% of non-remodelled ATB material was observed.ConclusionThe preliminary clinical, radiographical, and histological results of Bonmaker® autogenous tooth graft therapy indicate that ATB may be safely and successfully used as a grafting material for ARP. Optimal graft incorporation and histologically proven effective remodelling, as well as uneventful wound healing support the clinical application of ATB to minimize post-extraction hard tissue loss. Further research is needed to exploit the full potential of ATB and to evaluate the long-term peri-implant hard and soft tissue stability of ATB-treated post-extraction sites.

Alveolar Ridge Preservation in Mandibular Molars Using Mixture of Anorganic Bovine Bone (ABB) and Autogenous Particulate Vs Mixture of Injectable Platelets Rich Fibrin, ABB and Autogenous Particulates (Sticky Bone) (A Randomized Clinical Trial)

Alveolar Ridge Preservation in Mandibular Molars Using Mixture of Anorganic Bovine Bone (ABB) and Autogenous Particulate Vs Mixture of Injectable Platelets Rich Fibrin, ABB and Autogenous Particulates (Sticky Bone) (A Randomized Clinical Trial)

Alveolar Ridge Preservation in the Esthetic Maxillary Zone: Tuberosity Punch Technique of Gingiva and Bone: A Pilot Study

This paper aims to present an alveolar ridge preservation technique, using an autologous punch formed of hard and soft tissues harvested from the tuberosity area. Ten residual sockets in the anterior maxilla were filled with a punch of hard and soft tissues harvested from the tuberosity area. Clinical and radiographical data were collected at the surgical extraction time 0 (T0) and 5 months during implant placement (T1), from clinical and radiological measurements using cone-beam computed tomography scans and periapical radiographs. Core biopsy was harvested during implant placement for histological and histomorphometrical analysis. Clinically, the alveolar ridge presented a mean width of 10.3 mm before extraction which decreased to 8.85 mm at T1, where the mean horizontal loss is 1.45 mm (standard deviation [SD] 1.03 mm). The initial ridge mean height was 11.25 mm and increased to 12.85 mm after 5 months, where the mean vertical gain is 1.6 mm (SD 0.65 mm). The radiological evaluation shows a reduction in the horizontal dimension with a mean of 1 mm; however, the sockets show stability in the vertical dimensions. Histology showed a new lamellar bone formation with some areas of woven bone. Histomorphometric analysis showed that the percentage of new bone formed was 42.44 ± 5.54% and 48.62 ± 8.66% of the connective tissue and 8.94 ± 5.28% of the residual autogenous bone. At T1, the extraction sockets showed significantly lower vertical and horizontal bone changes, compared to T0. The described preservation punch technique resulted in greater stability in the horizontal and vertical dimensions after 5 months. Clinical and radiological results show that the punch of hard and soft tissue graft reduces hard and soft tissue dimensional alteration after tooth extraction. In addition, using autogenous bone showed histological new bone formation.

Is ridge preservation effective in the extraction sockets of periodontally compromised teeth? A randomized controlled trial.

To verify whether ridge preservation is effective in the reduction of dimensional loss and in bone formation compared to spontaneous healing in extraction sockets of periodontally compromised teeth. Twenty-six subjects requiring tooth extraction for stage III/IV periodontitis were randomly assigned to one of two interventions: alveolar ridge preservation using collagenated bovine bone mineral and a resorbable collagen membrane (test, RP) or spontaneous healing (control, SH). Six months later, postoperative cone-beam computed tomography (CBCT) was performed to measure the linear and volumetric changes of the sockets compared to baseline scans. Biopsies were retrieved at the implant site for histomorphometric calculations. Nonparametric tests were applied for statistical analysis. Significantly less shrinkage occurred in RP compared to SH, mainly in the crestal zone. The width loss difference between groups was 3.3mm and 2.2mm at 1mm and 3mm below the crest, respectively (p<.05). RP yielded a gain in socket height of 0.25mm, whereas a loss of -0.39mm was observed in SH (p<.05). The percentage of volume loss recorded in RP was also less than that recorded in SH (-26.53% vs -50.34, p<.05). Significantly less bone proportion was detected in biopsies from RP (30.1%) compared with SH (53.9%). A positive association between baseline bone loss and ridge shrinkage was found in SH but not in RP. Ridge preservation in extraction sockets of periodontally compromised teeth was effective in reducing the amount of ridge resorption.

A case series of profilometric changes in two implant placement protocols at periodontally compromised non-molar sites

Information regarding profilometric changes at a soft tissue level following implant placement with different protocols is insufficient. Therefore, this study aimed to comparatively investigate the profilometric tissue changes with respect to late implant placement following alveolar ridge preservation (LP/ARP) and early implantation (EP) in periodontally compromised non-molar extraction sites. Sixteen patients were randomly assigned to the following groups: implant placement 4 months post-ARP (group LP/ARP) and tooth extraction and implant placement 4–8 weeks post-extraction (group EP). Dental impressions were obtained immediately after final prosthesis insertion and at 3, 6, and 12 months. At the time of implant placement, bone augmentation was performed in the majority of the patients. Profilometric changes of the tissue contour were minimal between the final prosthesis insertion and 12 months in the mid-facial area (0.04–0.35 mm in group LP/ARP, 0.04–0.19 mm in group EP). The overall tissue volume increased in both groups (1.70 mm3 in group LP/ARP, 0.96 mm3 in group EP). In conclusion, LP/ARP and EP led to similar stability of the peri-implant tissue contour between the final prosthesis insertion and at 12 months. Moreover, the change of peri-implant tissue on the soft tissue level was minimal in both modalities.

Immediate implant in the posterior region combined with alveolar ridge preservation and sealing socket abutment: A retrospective 3D radiographic analysis.

Customized sealing socket abutment (SSA) has been claimed to optimize the peri-implant hard and soft tissues in type 1 implant placement. However, the evidence to claim the benefits of this technique over the use a conventional healing abutment remains weak. The aim of this retrospective study was to provide a 3D-radiographic evaluation of hard tissues changes following immediate implant placement in molar sites combined to ARP technique and installation of SSA. Baseline and follow-up (FU) CBCTs (from 1 to 5 years) of 26 patients were collected and included in the study. Baseline and FU CBCTs were superimposed and horizontal and vertical bone changes were assessed. A total of 26 patients and 27 implants were included. Horizontal bone remodeling was not significant in any of the measured areas except in the most cervical level, where a mean bone remodeling of 0.73 mm was found. Proximal and buccal vertical bone changes were not significant. Within the limits of a retrospective study, dimensional alveolar ridge changes 1 to 5 years after immediate implant placement in molar sites with simultaneous ARP technique and installation of SSA seem to be very limited.

A retrospective cohort study of how alveolar ridge preservation affects the need of alveolar ridge augmentation at posterior tooth implant sites

ObjectivesThe aim of this study was to assess whether alveolar ridge preservation (ARP) can reduce the need of ridge augmentation at posterior tooth sites.Material and methodsThis study enrolled patients who received dental implants at posterior tooth sites during 2013–2019. Demographic data and dental treatment histories were collected. Based on healing patterns after tooth extraction, patients were divided into ARP and spontaneous healing (SH) groups. Three surgical treatment plans were devised according to the alveolar bone volume on cone-beam computed tomography (CBCT). The three treatment plans were to perform implant alone, simultaneous guided bone regeneration (GBR) and implantation, and staged GBR before implantation. Statistical analyses were performed to determine relationships.ResultsThere were 92 implant records in the ARP group and 249 implant records in the SH group. A significant intergroup difference was observed regarding the frequency distribution of the treatment modality of staged GBR before implant (χ2 = 15.07, p = 0.0005). Based on the implant alone treatment modality and simple logistic regression, the SH pattern was related to staged GBR before implant (SH vs. ARP: crude odds ratio (OR) = 4.65, 95% confidence interval (CI) = 2.15–11.61, p = 0.0003). After adjusting confounding factors, the risk was still significant (adjusted OR = 5.02, 95% CI = 2.26–12.85, p = 0.0002).ConclusionsThe study results suggested that ARP is more likely to lead to the treatment modality of implant alone and reduce the need for staged GBR before implantation.Clinical relevanceThis study describes ARP capable of minimizing the need for staged GBR before implantation and shortening the treatment duration.

Polymeric non-spherical coarse microparticles fabricated by double emulsion-solvent evaporation for simvastatin delivery

Polymeric particles with non-spherical shape or coarse surface have distinct advantages for drug delivery, tissue regeneration and immunomodulation respectively, but it is not easy to control polymeric microparticles in required geometry and surface texture simultaneously. In this study, polymeric non-spherical microparticles with coarse surface were successfully prepared by double emulsion-solvent evaporation technique in the presence of ammonium bicarbonate and the formation mechanism was proposed. In addition, simvastatin was encapsulated in poly[lactic-co-(glycolic acid)] (PLGA) non-spherical microparticles with coarse surface by the same technique and the release kinetics in vitro was fitted as well, which not only enrich the encapsulation techniques of liposoluble drugs in polymeric non-spherical carriers but also envision the potential application for alveolar ridge preservation with local delivery of simvastatin.

Characterization of Extraction Sockets by Indirect Digital Root Analysis.

This study aimed to characterize extraction sockets based on indirect digital root analysis. The outcomes of interest were estimated socket volume and dimensions of the socket orifice. A total of 420 extracted teeth, constituting 15 complete sets of permanent teeth (except third molars), were selected. Teeth were scanned to obtain STL files of the root complex for digital analysis. After digitally sectioning each root 2.0 mm apical to the cementoenamel junction (CEJ), root volume was measured in mm3 and converted to cc. Subsequently, a horizontal section plane was drawn at the most zenithal level of the buccal CEJ, and the surface area (in mm2) and buccolingual and mesiodistal linear measurements of the socket orifice (in mm) were computed. Maxillary first molars exhibited the largest mean root volume (0.451 ± 0.096 cc) and mandibular central incisors the smallest (0.106 ± 0.02 cc). Surface area analysis demonstrated that mandibular first molars presented the largest socket orifice area (78.56 ± 10.44 mm2), with mandibular central incisors presenting the smallest area (17.45 ± 1.82 mm2). Maxillary first molars showed the largest mean socket orifice buccolingual dimension (11.08 ± 0.60 mm), and mandibular first molars showed the largest mean mesiodistal dimension (9.73 ± 0.84 mm). Mandibular central incisors exhibited the smallest mean buccolingual (5.87 ± 0.26 mm) and mesiodistal (3.52 ± 0.24 mm) linear dimensions. Findings from this study can be used by clinicians to efficiently plan extraction-site management procedures (such as alveolar ridge preservation via socket grafting and sealing) and implant provisionalization therapy, and by the industry to design products that facilitate site-specific execution of these interventions.

Alveolar Ridge Preservation Utilizing Composite (Bioceramics/Collagen) Graft: A Cone-Beam Computed Tomography Assessment in a Randomized Split-Mouth Controlled Trial

Background: The vast percentage of the alveolar bone resorption process happens within the first 12 to 24 weeks post extraction; however, this phenomenon is chronic, and the alveolar ridge continues to resorb. In order to prevent this reduction or at least recompense the loss of bone dimensions, the alveolar ridge preservation (ARP) technique was developed. Objectives: This research studied the vertical and horizontal bone dimensional changes as a result of non-molar teeth extraction alone against extraction with alveolar ridge preservation utilizing composite (bioceramics/collagen) graft by cone-beam computed tomography radiographies analyses. Material and Methods: This research was a randomized split-mouth controlled trial. 12 patients need extraction of the maxillary non-molar teeth were enrolled and allocated into 2 groups. 12 sockets after atraumatic extraction were filled with a composite graft in the role of the test group, 12 sockets left to unassisted healing after atraumatic extraction without any graft materials in the role of the control group. Two CBCT radiographs were taken at baseline and at 4 months after extraction for comparison. Both vertical and horizontal resorptions of the alveolar ridge were analyzed between test and control group by CBCT radiographs. Results: 4 months after extraction, there was a mean of vertical alveolar bone resorption compared with the baseline (0.56 ± 0.15 mm) in the test group and (1.47 ± 0.30 mm) in the control group. Whereas it was a mean of horizontal alveolar bone resorption compared with the baseline (0.90 ± 0.16 mm) in the test group and (2.26 ± 0.30 mm) in the control group. Therefore, there was a significant difference between the two groups. Conclusions: Within the limitations of this research, we demonstrated that the osteogen-plug technique significantly decreased the reduction of the bone dimensional in comparison to the tooth extraction alone, and showed that the dimensional change of the alveolar ridge after tooth extraction was minimized by using an osteogen-plug.

Meta-analysis of the effect of platelet-rich fibrin in alveolar ridge preservation

Meta-analysis of the effect of platelet-rich fibrin in alveolar ridge preservation

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

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

Effects of combined use of recombinant human fibroblast growth factor-2 and β-tricalcium phosphate on ridge preservation in dehiscence bone defects after tooth extraction: A split-mouth study in dogs.

Following tooth extraction, bone resorption is especially severe in cases complicated with buccal dehiscence bone defects. To minimize this, various bone graft materials have been used for alveolar ridge preservation. This study aimed to evaluate additional effects of the concomitant use of recombinant human fibroblast growth factor-2 (rhFGF-2) with β-tricalcium phosphate (β-TCP) on ridge preservation in a dehiscence defect model after tooth extraction in dogs. The maxillary first premolars of six beagle dogs were extracted and dehiscence defects of 4×4×5mm (mesio-distal width×bucco-palatal width×depth) were created. Bilateral defects were filled with β-TCP combined with 0.3% (w/v) rhFGF-2 (test sites) or the scaffold alone (control sites). Twelve weeks post-surgery, histologic and histometric evaluations were performed. Morphological measurements using micro-computed tomography revealed a significantly greater bone volume at the test sites (48.9±9.06 mm3 ) than at the control sites (38.8±7.24 mm3 ). Horizontal widths of the alveolar ridge at the coronal and middle position at the test sites (2.18±0.71mm, 2.93±0.53mm) were significantly greater than those at the control sites (1.47±0.41mm, 2.36±0.45mm, respectively). Regarding the histological parameters, the occupation rate of mineralized bone in the original defects was slightly higher at the test sites (44.07±10.19%) than that at the control site (41.15±6.56%). These results indicate that the adjunct use of rhFGF-2 with β-TCP is effective for alveolar ridge preservation in fresh extraction sockets with dehiscence defects.

The Impact of Double Layer Membrane Technique on Bone Regeneration in Postextraction Alveoli – A Pathohistological Experimental Study in Dogs

Abstract Post extraction alveolar ridge preservation is a preventive oral surgical procedure aimed to preserve the dimensions of the alveolar ridge after removal of the teeth. According to literature data, the utilization of guided bone regeneration for this purpose is absolutely justified. The aim of this study was to examine the effect of resorbable collagen membranes placed in two layers in respect to the application of membranes placed in one layer to the degree of bone regeneration after a tooth extraction. This experimental study was conducted on six adult dogs. In the first phase all four premolars were extracted on both sides in the lower jaw. After the volume-standardisation with bone drill, three post extraction alveoli were filled with bone substitute of equine origin and then covered with: collagen bioresor bable membrane of porcine origin; collagen bioresorbable membrane of equine origin; pericardial bioresorbable membrane of equine origin. The membranes on the left side were placed in single-layer and on the right side in double-layer manner. After different monitoring periods, histopathological analysis of the samples taken from the experimental regions was performed. A different degree of bone regeneration was achieved between experimental regions in which membranes were placed in one layer and those where membranes were placed in two layers. There was no difference between regions where membranes of different origin were placed in the same manner. The procedure of covering the post extraction alveoli, filled with bone substitute and with resorbable membranes placed in two layers resulted in a higher degree of bone regeneration compared to those where resorbable membranes were placed in one layer.

Effectiveness of bilayer porous polyethylene membrane for alveolar ridge preservation: A randomized controlled trial.

Porous polyethylene has been successfully used in several medical applications with good outcomes. Based on this, a new bilayer porous polyethylene membrane (B-PPM) was developed for possibly being used as a membrane in alveolar ridge preservation. To evaluate the clinical efficacy of a new B-PPM in comparison to high-density polytetrafluoroethylene membrane (d-PTFE) in alveolar ridge preservation. Thirty patients were randomized into two groups according to the membranes used to cover the socket (B-PPM or d-PTFE). Wound healing was monitored at day 1, 3, 7, 14, 28, and 4 months postoperatively. Dimensional changes of alveolar ridge were measured immediately after tooth extraction and at 4 months later using intraoral scanner and cone beam computed tomography. Bone cores were harvested before implant placement. Implant stability at insertion and prior to prosthesis delivery were also measured. No significant difference in socket wound closure between groups was observed excepting at day 14 that B-PPM showed a faster wound closure than d-PTFE (P = .03). Greater bone resorptions were seen on buccal than lingual side and on coronal than apical part of the alveolar ridge. No significant difference in dimensional changes of alveolar ridge, new bone formation, connective tissue content, residual bone grafts, and implant stability between two groups. B-PPPM was safe and effective for alveolar ridge preservation.

The effect of immediate implant placement on alveolar ridge preservation compared to spontaneous healing after tooth extraction: Soft tissue findings from a randomized controlled clinical trial.

To compare soft tissue dimensional changes and relative differences in soft and hard tissue volumes 4months after single-tooth extraction and three different treatment modalities: spontaneous healing (SH) and alveolar ridge preservation by means of a deproteinized bovine bone mineral and a collagen matrix, with (IMPL/DBBM/CM) or without (DBBM/CM) immediate implant placement. STL files from study casts obtained at baseline and after 4months were matched to calculate buccal soft tissue linear and volumetric changes. DICOM files from CBCTs were superimposed to STL files allowing the evaluation of soft tissue thickness at baseline and 4months. Mean horizontal reduction accounted for 1.46±0.20 (SH), 0.85±0.38 (DBBM-CM) and 0.84±0.30 IMPL/DBBM-CM, with no statistical differences. Soft tissue thickness had a significant mean increase of 0.95 for SH group, compared to a non-significant mean decrease for DBBM-CM (0.20) and IMPL/DBBM-CM groups (0.07). A preservation technique with DBBM-CM, with or without immediate implant placement, did not reduce the horizontal linear and volumetric changes at the buccal soft tissue profile significantly at 4months after tooth extraction when compared to spontaneous healing. This is due to a significant increase in soft tissue thickness in spontaneously healing sites.

Three-dimensional analysis of dimensional changes after alveolar ridge preservation with bone substitutes or plasma rich in growth factors: Randomized and controlled clinical trial.

To evaluate alveolar ridge dimensional changes of different alveolar ridge preservation techniques after 3 months of tooth extraction and to compare the efficacy of autologous plasma rich in growth factor (PRGF) to the bone substitutes in alveolar ridge preservation and sites left to heal spontaneously. Forty patients requiring tooth extraction in the anterior maxilla were randomly allocated to the four following treatment modalities: spontaneous healing (control), natural bovine bone mineral covered with resorbable native collagen membrane (BBM/CM), freeze-dried bone allograft covered with resorbable native collagen membrane (FDBA/CM) and PRGF alone. Cone beam computed tomography (CBCT) scans were taken after surgery and 3 months later. The measurements of height and width (at 1, 3, and 5 mm below the crest) were performed after superimposing the 2 consecutive CBCT scans. The greatest horizontal alveolar bone resorption at 1 mm below bone crest was observed in the control group (-1.61 ± 1.76 mm, P = .037), whereas the least reduction in width was found in the BBM/CM group (-0.68 ± 0.67 mm, P = .037). The most pronounced alveolar height reduction was observed in the control group (-0.86 ± 0.43 mm), whereas alveolar ridge preservation with BBMC/CM (-0.26 ± 0.91 mm) and PRGF (-0.54 ± 0.86 mm) successfully reduced the alveolar height reduction as compared to the control group. Alveolar ridge preservation technique in the esthetic zone using BBM/CM or using PRGF is beneficial to reduce horizontal and vertical bone changes.

Leukocyte and Platelet-Rich Fibrin Have Same Effect as Blood Clot in the 3-Dimensional Alveolar Ridge Preservation. A Split-Mouth Randomized Clinical Trial

Leukocyte- and platelet-rich fibrin (L-PRF) has been used for alveolar ridge preservation (ARP) in postextraction tooth sockets. However, current reports have measured its effectiveness in linear measurements of 3-dimensional ridge preservation. The purpose of this study was to determine the effectiveness of the use of L-PRF filling versus natural clot blood healing in ARP according to the clinical, radiographic, and volumetric measurements of postextraction tooth sockets. A split-mouth randomized clinical trial was designed. Healthy patients who needed bilateral extraction of upper third molars were selected. After the tooth extraction, the socket was filled and distributed randomly with L-PRF and the contralateral socket only with the blood clot. The dimensional change of soft tissue healing around the sockets, and the length, depth, and difference of bone formation were examined using standardized periapical radiographs. Volumetric measurement variation of the sockets was evaluated by 3-dimensional scanning of dental casts. Changes of all measures were analyzed at 7 days (initial) and 3 months (final) after the tooth extraction and compared between both groups (t test; P<.05). Sixteen patients (aged 24.75±3.53years; 56.25% women) participated. Measurements of wound healing and the length, depth, and difference of bone formation were similar for both study groups at initial and final times. The calculation of initial-final volumetric socket variation was 15.45±13.12μL using L-PRF and 14.12±11.23μL using blood clot (P=.78). L-PRF filling showed the same dimensional and volumetric behavior as normal blood clot healing in the ARP of postextraction tooth sockets. Future investigations will have to analyze the use of surgical models and digital instruments in ARP techniques.

Evaluation of poly lactic-co-glycolic acid-coated β-tricalcium phosphate for alveolar ridge preservation: A multicenter randomized controlled trial.

Alveolar ridge preservation via socket grafting (ARP-SG) is indicated to attenuate physiologic alveolar bone resorption as a consequence of tooth extraction. However, a specific bone grafting material that is patently superior has not been identified yet. The aim of this randomized controlled trial was to evaluate the efficacy of a moldable alloplastic graft, Poly Lactic-Co-Glycolic Acid-Coated β-Tricalcium Phosphate (PLGA-β-TCP), for ARP purposes [Group A] compared to freeze-dried bone allograft (FDBA) particles covered with a rapidly absorbable collagen dressing (RACD) (Group B) in function of a panel of radiographic, histomorphometric, and implant-related outcomes. Patients in need of extraction of a single posterior tooth (premolar or molar) and subsequent replacement with a dental implant were recruited and randomly allocated into one of the two treatment groups. Follow-up visits took place at 1, 2, 4, 8, and 16weeks. Cone-beam Computed Tomography (CBCT) scans were obtained at baseline and at 16weeks. Sites were re-entered at 20weeks for bone core biopsy harvesting and subsequent implant placement. After delivery of the final implant-supported restoration, follow-up visits were scheduled at 6 and 12 months to monitor peri-implant tissue health and marginal bone levels using standardized intraoral periapical radiographs. A total of 45 patients were initially enrolled in the study, of whom 43 received an implant and 32 completed the study. Healing was uneventful in all sites after ARP-SG and implant placement. No site required bone augmentation to allow for implant placement. CBCT scan analyses showed no statistically significant differences between groups in terms of reduction of horizontal width, midbuccal / midlingual height and ridge volume. Histomorphometric assessments revealed a statistically significant difference between both groups in terms of mineralized tissue formation (Group A=27.0% ± 22.1%versus Group B=38.2% ± 12.5%; P<0.05). On the contrary, no significant differences were observed regarding percent of remaining bone grafting material and non-mineralized tissue. No implant failed throughout the study period and marginal bone level change was negligible in both groups. Although a higher proportion of mineralized tissue was associated with the use of FDBA+RACD compared to PLGA-β-TCP alone, both ARP-SG approaches rendered comparable outcomes in terms of maintenance of alveolar bone dimensions, feasibility of implant placement, implant survival, and peri-implant bone level stability up to 12 months post-loading.

Comparison of Dehydrated Human Amnion-Chorion and Type 1 Bovine Collagen Membranes in Alveolar Ridge Preservation: A Clinical and Histological Study

Alveolar ridge preservation maintains ridge dimensions and bone quality for implant placement. The aim of this randomized controlled clinical study is to compare the use of a human amnion-chorion membrane to a collagen membrane in an exposed-barrier ridge preservation technique. Furthermore, this study will determine if intentional membrane exposure compromises ridge dimensions and bone vitality. Forty-three patients requiring extraction and delayed implant placement were randomly assigned into either the experimental or control group. Twenty-one participants received human amnion-chorion membrane (test) during ridge preservation while 22 participants received the collagen membrane (control). In both groups, demineralized freeze-dried bone allografts were used to graft the socket and primary closure was not achieved. The patients underwent implant placement after an average healing period of 19.5 weeks, and 2.7 × 8-mm core bone specimens were obtained for histomorphometric analyses. The clinical ridge dimensions were measured after extraction and at the time of delayed implant placement. No significant difference was observed in the mean vital bone formation between the experimental (51.72 ± 8.46%) and control (49.96 ± 8.31%; P > .05) groups. The bone height and width did not differ, as determined by clinical measurements (P > .05). Using either a human amnion-chorion membrane or type 1 bovine collagen as the open barrier did not change healing, compromise ridge dimensions, or affect bone vitality between the 2 groups.