Alveolar ridge regeneration of damaged extraction sockets using deproteinized porcine versus bovine bone minerals: A randomized clinical trial

Alveolar Ridge Preservation Using a Collagenated Xenograft: A Randomized Clinical Trial

OBJECTIVES

This study sought to evaluate the efficacy of cancellous bovine bone mineral granules and 10% porcine collagen (deproteinized bovine bone mineral with collagen [DBBM-C]; (OCS-B Collagen® [Straumann XenoFlex], NIBEC, Korea) in a mouldable block form, with or without socket seal, using autogenous free gingival graft (FGG).

METHODS

Fifty-four patients were included and randomly assigned to one of three groups: (1) spontaneous healing (control group), (2) alveolar ridge preservation (ARP) using DBBM-C (DBBM-C group), and (3) ARP employing DBBM-C sealed with FGG (DBBM-C/FGG group). Bone biopsy and implant fixture placement were performed 180 days after ARP. Cone-beam computed tomography, histological analysis, implant stability, and three-dimensional volumetric analysis were conducted.

RESULTS

Of the 54 patients, 4 dropped out owing to loss of follow-up and osseointegration failure. The changes in alveolar bone during follow-up were not significantly different. Between 84- and 180-day postextraction, the volume of the DBBM-C and DBBM-C/FGG groups was maintained at 3 mm below the alveolar ridge crest (0.72 ± 0.80 mm, 6.05 ± 6.69%), whereas the volume in the control group decreased (-0.37 ± 1.31 mm, -2.10% ± 8.37%) (P = .026). The DBBM-C/FGG group exhibited less horizontal ridge resorption at 1 mm below the alveolar crest (-9.19 ± 5.09 mm, -73.67% ± 32.53%) between preextraction and 84 days postextraction (P = .049). In all groups, the implant stability quotient remained above 70.

CONCLUSIONS

Within the limitations of this study, both ARP using DBBM-C with and without socket sealing effectively preserved the width dimension of the alveolar ridge, with no significant difference in alveolar bone resorption. However, socket sealing appeared to enhance the stability of the bone graft and bone quality.

CLINICAL RELEVANCE

The use of DBBM-C for ARP seems to aid in volume maintenance as compared with spontaneous healing. Gingival sealing with an FGG can help maintain the width of the alveolar ridge. This clinical trial was not registered prior to participant recruitment and randomization. This study was registered at WHO ICTRP (https://trialsearch.who.int/Trial2.aspx?TrialID=KCT0008266).

Assessment of soft and hard tissue changes following micro crestal flap-Alveolar ridge preservation and augmentation at molar extraction sites in patients with stage III/IV periodontitis: A randomized controlled trial

AIM

This study aimed to assess hard and soft tissue contour changes following micro crestal flap-alveolar ridge preservation (MCF-ARP) and natural healing (NH) in periodontally compromised molar extraction sites and to analyse the feasibility and need for bone augmentation during implant therapy.

MATERIALS AND METHODS

Fifty-six patients with 70 sites were randomized into two groups at the site level (35 sites from 31 patients in the test group and 35 sites from 29 patients in the control group). Among whom, four patients contributed one tooth to the control group and one tooth to the test group. Hard tissue indicators were measured using cone beam computed tomography performed before tooth extraction and 6 months after surgery. Soft tissue contour changes were assessed using intraoral scanning performed before and immediately after surgery and also 2 weeks and 1, 3 and 6 months after surgery.

RESULTS

Six months after surgery, the MCF-ARP group showed less resorption in buccal bone height (p = .032) and greater augmentation in central bone height (p = .001) and ridge width (p = .009). The mean, vertical and horizontal collapse of buccal soft tissue contour in the MCF-ARP group were 0.95 mm (p = .010), 0.61 mm (p = .019) and 0.56 mm (p = .013) less than that in the NH group, respectively. There were significantly (p = .007) fewer sites in the MCF-ARP group than in the NH group (0% vs. 26.7%) for staged bone augmentation and more sites that could be treated with simple implant procedure in the MCF-ARP group than in the NH group (71.9% vs. 56.6%).

CONCLUSIONS

Compared with NH, MCF-ARP reduced bone resorption in periodontally compromised molar extraction sites and maintained the buccal soft tissue contour. MCF-ARP reduces the need for complex bone augmentation procedures in implant therapy.

TRIAL REGISTRATION

Chinese Clinical Trial Register (ChiCTR) ChiCTR2200056335. Registered on 4 February 2022, Version 1.0.

In vivo experimental study comparing alveolar ridge preservation versus guided bone regeneration after unassisted socket healing at intact and damaged sites in narrow alveolar ridges

BACKGROUND

To compare bone regeneration and dimensional alteration of alveolar ridge at intact and damaged extraction sockets after alveolar ridge preservation (ARP) and implant placement versus unassisted socket healing followed by guided bone regeneration (GBR) with simultaneous implant placement.

METHODS

In 6 beagle dogs, 3 types of extraction sockets in the mandible were created: (1) intact sockets, (2) 1-wall defect sockets and (3) 2-wall defect sockets. The sockets were allocated to undergo either (1) ARP and implant placement 8 weeks later (ARP group) or (2) GBR with simultaneous implant placement after 8 weeks of unassisted socket healing (GBR group). After an additional healing period of 8 weeks, bone regeneration and dimensional changes were evaluated radiographically and histologically.

RESULTS

GBR showed superior bone formation and greater bone gains compared to ARP, regardless of the initial extraction-socket configuration. Although ARP maintained the preexisting alveolar ridge dimensions, peri-implant bone defects were still detected at 8 weeks of follow-up. Histomorphometric analyses confirmed that GBR increased dimensions of the alveolar ridge compared to baseline, and the augmentation and bone regeneration were greater with GBR than with ARP.

CONCLUSION

Early implant placement with ARP can mitigate alveolar ridge changes in the narrow alveolar ridge. However, early implant placement with simultaneous GBR creates the conditions for enhanced bone regeneration around the implant and greater ridge augmentation compared to ARP, irrespective of the extraction-socket configuration.

Effect of alveolar ridge preservation at periodontally compromised molar extraction sockets: A retrospective cohort study

BACKGROUND

To date, the clinical evidence regarding the effectiveness of alveolar ridge preservation (ARP) in restricting alveolar bone height and width change after extraction at periodontally compromised molar extraction sockets still remains controversial. This retrospective cohort study aims to evaluate the effect of ARP in molars extracted for periodontal reasons.

METHODS

Retrospective data were collected from patient electronic records from January 2019 to December 2023. Patients with Stage III/IV periodontitis who underwent extraction of molars for periodontal reasons were screened for eligibility. The outcomes included the horizontal and vertical dimensions of alveolar bone. The need for additional augmentation procedure during implantation was also evaluated. A linear regression model was used to adjust for known confounders.

RESULTS

A total of 80 sockets were included in this study, of which 27 sockets received ARP therapy after extraction while 53 sockets experienced natural healing (NH). ARP resulted in significantly less bone height change in the periodontally compromised molar sites compared to the NH group (p < 0.001). In sockets displaying a height disparity of >2 mm between the buccal and palatal/lingual walls, the ARP group exhibited advantageous outcomes in terms of ridge width change, surpassing the NH group (p = 0.004). Moreover, the percentage for additional augmentation was significantly reduced in the ARP compared to the NH group (p = 0.006). Age, sex, smoking, jaw, location, and buccal wall thickness did not show any significant effect on bone height change.

CONCLUSION

ARP had benefits on limiting ridge resorption subsequent to molar extraction for periodontal reasons.

From Basic Science to Clinical Practice: A Review of Current Periodontal/Mucogingival Regenerative Biomaterials

Periodontitis is a dysbiosis-driven inflammatory disease affecting the tooth-supporting tissues, characterized by their progressive resorption, which can ultimately lead to tooth loss. A step-wise therapeutic approach is employed for periodontitis. After an initial behavioral and non-surgical phase, intra-bony or furcation defects may be amenable to regenerative procedures. This review discusses the regenerative technologies employed for periodontal regeneration, highlighting the current limitations and future research areas. The search, performed on the MEDLINE database, has identified the available biomaterials, including biologicals (autologous platelet concentrates, hydrogels), bone grafts (pure or putty), and membranes. Biologicals and bone grafts have been critically analyzed in terms of composition, mechanism of action, and clinical applications. Although a certain degree of periodontal regeneration is predictable in intra-bony and class II furcation defects, complete defect closure is hardly achieved. Moreover, treating class III furcation defects remains challenging. The key properties required for functional regeneration are discussed, and none of the commercially available biomaterials possess all the ideal characteristics. Therefore, research is needed to promote the advancement of more effective and targeted regenerative therapies for periodontitis. Lastly, improving the design and reporting of clinical studies is suggested by strictly adhering to the Consolidated Standards of Reporting Trials (CONSORT) 2010 statement.

Biomaterial scaffolds in maxillofacial bone tissue engineering: A review of recent advances

Maxillofacial bone defects caused by congenital malformations, trauma, tumors, and inflammation can severely affect functions and aesthetics of maxillofacial region. Despite certain successful clinical applications of biomaterial scaffolds, ideal bone regeneration remains a challenge in maxillofacial region due to its irregular shape, complex structure, and unique biological functions. Scaffolds that address multiple needs of maxillofacial bone regeneration are under development to optimize bone regeneration capacity, costs, operational convenience. etc. In this review, we first highlight the special considerations of bone regeneration in maxillofacial region and provide an overview of the biomaterial scaffolds for maxillofacial bone regeneration under clinical examination and their efficacy, which provide basis and directions for future scaffold design. Latest advances of these scaffolds are then discussed, as well as future perspectives and challenges. Deepening our understanding of these scaffolds will help foster better innovations to improve the outcome of maxillofacial bone tissue engineering.

Potentials of pure xenograft materials in maxillary ridge augmentation: A case series

Many patients require edentulous ridge augmentation for dental implant placement. The main objective of this study was to evaluate the results of maxillary edentulous ridge augmentation exclusively with xenograft materials with and without simultaneous sinus floor elevation. This study reports the data retrieved from the records of 16 patients. The treatment outcome was assessed at least 6 months, postoperatively. Paired samples t-test or Wilcoxon Signed Rank test was used to compare the pre-and postoperative ridge dimensions. Dental implants were placed simultaneously in 7 patients, while 9 patients underwent delayed implant placement. In total, 68 implants were placed, and 12 patients also underwent maxillary sinus floor augmentation. A significant bone gain was achieved in both horizontal and vertical dimensions of edentulous maxillary ridges (P < 0.001). Ridge width increased by an average of 4.35 ± 1.90 mm (95% CI: 3.84 to 4.85 mm) while ridge height in areas of sinus floor augmentation increased by 8.19 ± 2.91 mm (95% CI: 7.33 to 9.05 mm). Within the study limitations, it appears that maxillary ridge augmentation according to the guided bone regeneration (GBR) protocols with exclusive use of xenograft particulate materials can provide optimal bone quantity for dental implant placement.

Horizontal ridge augmentation with porcine bone-derived grafting material: a long-term retrospective clinical study with more than 5 years of follow-up

Objectives

The purpose of this study was to evaluate the outcomes of implants placed in horizontally augmented alveolar ridges using porcine bone grafts and to investigate the long-term stability of the porcine bone grafts.

Materials and Methods

A retrospective analysis was conducted on 49 sites that underwent horizontal ridge augmentation using porcine bone grafts and implant placement with a follow-up period longer than 5 years. Furthermore, additional analysis was conducted on 24 sites where porcine bone grafts were used exclusively for horizontal ridge augmentation and implant placement.

Results

The mean follow-up period after prosthesis loading was 67.5 months, with a mean marginal bone loss of 0.23 mm at 1 year and a cumulative mean marginal bone loss of 0.40 mm over the entire follow-up period. Of the 49 implants, 2 were lost and 3 did not meet the success criteria, resulting in a survival rate of 95.9% and a success rate of 89.8%. In 24 sites, the mean marginal bone loss was 0.23 mm at 1 year and 0.41 mm at 65.8 months, with 100% survival and success rates.

Conclusion

Porcine bone grafts can be successfully used in horizontal ridge augmentation for implant placement in cases of ridges with insufficient horizontal width.

Alveolar ridge preservation of damaged or periodontally compromised extraction sockets with bovine- and porcine-derived block bone substitutes: A retrospective case-control study

PURPOSE

Alveolar ridge preservation (ARP) was introduced to minimize postextraction alveolar bone loss and extraction socket remodeling; however, current knowledge of the ARP procedure for nonintact extraction sockets is still limited and inconclusive. This retrospective study aimed to evaluate the difference between using deproteinized bovine bone mineral with 10% collagen (DBBM-C) and deproteinized porcine bone mineral with 10% collagen (DPBM-C) when performing ARP procedures in damaged or periodontally compromised extraction sockets based on clinical, radiographic, and profilometric outcomes.

METHODS

In total, 108 extraction sockets were grafted with 67 DBBM-C and 41 DPBM-C. Changes in radiographic (horizontal width and vertical height) and profilometric outcomes were measured after the ARP procedure and before the implant surgery. Postoperative discomfort (including the severity and duration of pain and swelling), early wound healing outcomes (including spontaneous bleeding and persistent swelling), implant stability, and treatment modalities for implant placement were also assessed.

RESULTS

Radiographically, the DBBM-C group decreased by -1.70 ± 2.26 mm (-21.50%) and - 1.39 ± 1.85 mm (-30.47%) horizontally and vertically, and the corresponding DPBM-C group decreased by -1.66 ± 1.80 mm (-20.82%) and -1.44 ± 1.97 mm (-27.89%) horizontally and vertically at an average of 5.6 months. There were no serious or adverse complications in any of the cases, and none of the measured parameters differed significantly between the groups.

CONCLUSION

Within the limitations of this study, ARP with DBBM-C and DPBM-C showed similar clinical, radiographic, and profilometric outcomes in nonintact extraction sockets.

Soft tissue outcomes following alveolar ridge preservation with/without primary flap closure for periodontally damaged extraction socket: A randomized clinical trial

INTRODUCTION

The changes in soft tissue profile following alveolar ridge preservation (ARP) with/without primary flap closure (PC) in periodontally damaged sockets have yet to be discovered.

METHODS

For periodontally damaged non-molar extraction sockets, ARP with PC (group PC)/without PC (group SC) was performed using granule-type xenogeneic bone substitute material and a collagen barrier. Intraoral scans were performed at the time of ARP and 4 months thereafter. Superimposition of STL files was performed to examine tissue change on the soft tissue level. The level of mucogingival junction (MGJ) was also evaluated.

RESULTS

A total of 28 patient (13 in group PC, 15 in group SC) completed the study. Soft tissue profile change was evaluated only when the measurement level was located on the non-mobile tissue. Group PC tended to shrink less on the long axis of the extraction socket than group SC (-4.3 ± 3.1 mm vs. -5.9 ± 4.4 mm at the 1 mm below the pre-extraction gingival margin, p > 0.05). Profilometric analysis (on the region of interest) also have a tendency of less tissue profile change in group PC than group SC (-1.0 ± 0.8 mm vs. -1.3 ± 0.5 mm, p > 0.05). The MGJ level change was not statistically significantly different between the groups (p > 0.05) even though the MGJ level was located more apically at 4 months in group SC compared with group PC.

CONCLUSIONS

Alveolar ridge preservation with PC tended to yield less soft tissue shrinkage than ARP without PC.

A novel porcine dentin-derived bone graft material provides effective site stability for implant placement after tooth extraction: a randomized controlled clinical trial

OBJECTIVES

Assessment of the clinical performance of a porcine dentin-derived particulate bone graft material for bone regeneration after tooth extraction with implant placement at 4 months, in comparison to a commercially available porcine bone-derived graft.

MATERIAL AND METHODS

This study was a randomized, parallel-group, semi-double-blinded clinical trial evaluating the clinical safety, tolerability, and performance of Ivory Dentin Graft™ in comparison with a commercial bone-derived material in alveolar ridge preservation following tooth extraction (registered at ClinicalTrials.gov, May 12th, 2017, Identifier NCT03150472). Extraction sites were grafted with test or comparator material and a titanium implant placed at 4 months after taking a graft site biopsy. Primary endpoints were the extent of new bone growth and bone-graft integration at 4 months.

RESULTS

The dentin graft material had statistically significantly more new bone formation (60.75% vs 42.81%, p = 0.0084, N = 20 vs 16), better bone-graft integration scores (good integration in 85% vs 40%, p = 0.0066), and higher mean radiodensity of the bone (981.5HU vs 727.7HU, p = 0.0011) at the graft site compared to the bone-derived material. The mean implant insertion torque force was similar for the dentin and bone materials (34.75 Ncm vs 34.06 Ncm). Titanium implant placement was successful in 95% of patients with the dentin graft material compared to 81.25% for the bone graft. Both materials had similar clinical safety and tolerability as determined by adverse events and local site reactions. Physician-assessed ease of grafting and ease of implant placement on a 10-point scale showed no statistical differences (8.78 vs 8.27, p = 0.2355; 8.05 vs 8.75, p = 0.1118, respectively).

CONCLUSIONS

A porcine dentin-derived bone graft material has clinical safety, tolerability, and performance for implant placement at 4 months after tooth extraction at least as good as a commercial bone-derived material.

CLINICAL RELEVANCE

The availability of porcine dentin-derived bone graft material allows wider use of dentin-derived material which has so far only been available in the form of autologous dentin from the patient's own teeth.

Primary flap closure in alveolar ridge preservation for periodontally damaged extraction socket: A randomized clinical trial

INTRODUCTION

The effect of primary wound closure (PC) on alveolar ridge preservation (ARP) in periodontally damaged sockets has yet to be fully discovered.

METHODS

Periodontally damaged sockets were allocated to one of the following groups: (1) ARP with PC (group PC), and (2) ARP without PC (group secondary wound closure [SC]). Following tooth extraction and flap elevation, granule-type xenogeneic bone substitute material and a collagen barrier were applied. Ridge change was evaluated using cone-beam computed tomographic (CBCT) scans immediately after ARP and at 4 months. Core biopsy specimens were examined histomorphometrically.

RESULTS

A total of 28 patients were included in the analysis (13 in group PC, 15 in group SC). Histomorphometrically, the percentage of newly formed bone was 26.2 ± 17.7% and 24.6 ± 18.4% in groups PC and SC, respectively (independent t-test, degree of freedom [df] = 25, p > 0.05). Horizontal ridge changes on CBCT were -4.9 ± 3.1 mm and - 4.2 ± 2.5 mm in groups PC and SC at the 1 mm level below the ridge crest, respectively (independent t-test, df = 26, p > 0.05). Approximately half of the sites required additional bone augmentation at implant placement.

CONCLUSIONS

ARP with/without PC yielded similar new bone formation and radiographic ridge change. This clinical trial was not registered prior to participant recruitment and randomization (https://cris.nih.go.kr/cris/search/detailSearch.do/19718).

Alveolar ridge preservation in extraction sockets of periodontally compromised teeth: a systematic review and meta-analysis

OBJECTIVES

Alveolar ridge preservation (ARP) procedures can limit bone changes following tooth extraction. However, the role of ARP in periodontally compromised socket lacks strong scientific evidence. The aim of this systematic review and meta-analysis was to evaluate the outcomes of ARP following extraction of periodontally compromised teeth in comparison to extraction alone in terms of hard tissue changes, need for additional augmentation at the time of implant placement and patient-reported outcomes.

MATERIAL AND METHODS

Electronic databases were searched to identify randomized controlled trials (RCTs) that compared ARP in periodontally compromised sockets to spontaneous socket healing. The risk of bias was assessed using the Cochrane Collaboration's Risk of Bias tool.

RESULTS

Five studies with 134 extraction sockets in 126 participants were included. Of these, ARP was performed in 77 sites, while the remaining sites were intentionally left to heal without any ARP treatment. The follow-up time varied between six and 12 months. Overall meta-analysis showed significant differences in changes in ridge height (mean difference (MD) -0.95; 95% confidence interval (CI) -1.43 to -0.47; P = 0.0001) and bone volume (MD -38.70; 95% CI -52.17 to -25.24; P < 0.0001) in favour of ARP. The use of ARP following extraction of periodontally compromised tooth was also associated with significantly less need for additional bone grafting at the time of implant placement.

CONCLUSIONS

Within the limitation of this review, ARP following extraction of periodontally compromised teeth may have short-term positive effects on alveolar ridge height and bone volume and minimize the need for additional augmentation procedures. However, the evidence is of very low to low certainty.

Three-dimensionally printed biphasic calcium phosphate blocks with different pore diameters for regeneration in rabbit calvarial defects

Background

Biphasic calcium phosphate (BCP) is the most frequently used synthetic bone substitutes, which comprises a combination of hydroxyapatite (HA) and beta-tricalcium phosphate (b-TCP). Thanks to the recent advances in digital dentistry and three-dimensional (3D) printing technology, synthetic block bone substitutes can be customized to fit individual defect morphologies. The diameter of the pores can influence the rate of bone formation and material resorption. The aim of this study was to compare three-dimensionally printed biphasic calcium phosphate (BCP) block bone substitutes with different pore diameters (0.8-, 1.0-, and 1.2- mm) for use in the regeneration of rabbit calvarial defects.

Methods

Four circular defects were formed on the calvaria of ten rabbits. Each defect was randomly allocated to one of the following study groups: (i) control group, (ii) 0.8-mm group, (iii) 1.0-mm group, and (iv) 1.2-mm group. All specimens were postoperatively harvested at 2 and 8 weeks, and radiographic and histomorphometric analyses were performed on the samples.

Results

Histologically, the BCP blocks remained unresorbed up to 8 weeks, and new bone formation occurred within the porous structures of the blocks. After the short healing period of 2 weeks, histomorphometric analysis indicated that new bone formation was significantly greater in the BCP groups compared with the control (p < 0.05). However, there were no significant differences between the groups with different pore diameters (p > 0.05). At 8 weeks, only the 1.0-mm group (3.42 ± 0.48 mm², mean ± standard deviation) presented a significantly larger area of new bone compared with the control (2.26 ± 0.59 mm²) (p < 0.05). Among the BCP groups, the 1.0- and 1.2-mm groups exhibited significantly larger areas of new bone compared with the 0.8-mm group (3.42 ± 0.48 and 3.04 ± 0.66 vs 1.60 ± 0.70 mm², respectively).

Conclusions

Within the limitations of this study, the BCP block bone substitutes can be applied to bone defects for successful bone regeneration. Future studies should investigate more-challenging defect configurations prior to considering clinical applications.

A three-in-one alveolar process reconstruction protocol for maxillary molar sites with severe residual bone height deficiency: A proof-of-concept pilot study

BACKGROUND

Implant placement in maxillary molar sites with severe height deficiency often requires multiple surgeries, which was time-consuming, invasive, and subject to serious postoperative complications.

PURPOSE

To introduce and assess a three-in-one technique (extraction, alveolar ridge preservation [ARP], and sinus elevation) for augmenting deficiency maxillary molar alveolar ridges.

MATERIAL AND METHODS

Fourteen patients with severe posterior maxillary ridge height deficiency underwent extraction, sinus elevation via an intrasocket window and ARP using sticky bone and then covered with acellular dermal matrix (ADM). Primary closure was intentionally not obtained. Cone-beam computed tomography and periapical radiography were used to measure dimensional ridge changes over time. Bone biopsies were taken at implant placement 7-21 months after surgery, which proceeded without additional grafting. Peri-implant soft tissue was assessed after 8-12 months of functional loading.

RESULTS

Maxillary molar sites (13 first molars, 1 second molar) with a mean sinus floor height of 1.73 ± 0.86 mm and mean buccal plate thickness of 1.62 ± 1.15 mm were elevated and grafted. Immediately after surgery, the mean sinus floor height was 14.03 ± 1.97 mm and the alveolar thickness at virtual implant platform level was 12.99 ± 1.88 mm. After 5-9 months healing, those measurements decreased by 2.45 ± 1.73 mm (p = 0.000) and 3.88 ± 3.95 mm (p = 0.006), respectively. Healed ridges were composed of 18.74% ± 4.34% mean vital bone and 19.08% ± 9.10% mean residual graft. After 8-12 months of functional loading, the peri-implant tissue appeared healthy, and there was a mean marginal bone loss of 0.12 ± 0.11 mm.

CONCLUSIONS

For maxillary first molar sites with severe sinus floor height deficiency, this minimally invasive three-in-one treatment allows for uncomplicated implant placement and short-term functional stability.

Evaluation of implant placement following ridge preservation in periodontally compromised molar extraction sockets: Three-year results of a prospective cohort study

OBJECTIVE

To investigate the 3-year implant-related outcomes following alveolar ridge preservation in periodontally compromised molar sockets.

MATERIAL AND METHODS

Thirty implants were placed in 26 patients following either ridge preservation (test, n = 16) or natural healing (control, n = 14) at deficient molar extraction sites after a 6-month healing period. The need for additional augmentation procedures at implant placement was recorded. Patients were assessed for 3 years following a definitive restoration. Patient information being collected are modified plaque index, the modified sulcus bleeding index, the peri-implant probing depth clinically, and alterations of marginal bone level (MBL) radiographically.

RESULTS

There was a 100% survival rate of implants in both groups after 3-year follow-up. During implant placement operation, 35.7% in the control group and 6.3% in the test group required additional augmentation procedures. No statistically significant differences were determined for peri-implant parameters and marginal bone levels between the two groups. The overall mean difference of MBL was 0.072 mm (95% CI [-0.279, 0.423]) during the 3 years of follow-up. The success rate was 81.2% in the test and 78.6% in the control group.

CONCLUSIONS

Implants placed into periodontally compromised molar extracted sites after ridge augmentation resulted comparable outcomes to implants placement at naturally healed sites after 3-year functional loading.

Vertical ridge augmentation feasibility using unfixed collagen membranes and particulate bone substitutes: A 1- to 7-year retrospective single-cohort observational study

Aim

To determine whether vertical ridge augmentation (VRA) can be obtained through guided bone regeneration (GBR) using exclusively resorbable collagen membranes and particulate bone substitutes without additional stabilization.

Materials and Methods

This study retrospectively examined 22 participants who underwent VRA with staged or simultaneous implant placement. The vertical defects of all participants were filled with particulate bone substitutes and covered with resorbable collagen membranes. The augmented sites were stabilized with unfixed collagen membranes and the flap without any additional fixation. The augmented tissue height was assessed using cone‐beam computed tomography at baseline, immediately after surgery, and at annual follow‐ups.

Results

The vertical bone gain of the 22 augmented sites amounted to 6.48 ± 2.19 mm (mean ± SD) immediately after surgery and 5.78 ± 1.72 mm at 1‐ to 7‐year follow‐up. Of the 22 augmented sites, 18 exhibited changes of less than 1 mm, while the other 4 showed changes of greater than 1 mm. Histological observation of three representative cases revealed new bone apposition on the remaining material.

Conclusion

The present findings indicate that GBR procedures using exclusively collagen membranes and particulate biomaterials without any additional fixation are feasible options for VRA.

Effectiveness of a Nanohydroxyapatite-Based Hydrogel on Alveolar Bone Regeneration in Post-Extraction Sockets of Dogs with Naturally Occurring Periodontitis

Pathological mandibular fracture after dental extraction usually occurs in dogs with moderate to severe periodontitis. A nanohydroxyapatite-based hydrogel (HAP hydrogel) was developed to diminish the limitations of hydroxyapatite for post-extraction socket preservation (PSP). However, the effect of the HAP hydrogel in dogs has still not been widely investigated. Moreover, there are few studies on PSP in dogs suffering from clinical periodontitis. The purpose of this study was to evaluate the effectiveness of the HAP hydrogel for PSP in dogs with periodontitis. In five dogs with periodontitis, the first molar (309 and 409) of each hemimandible was extracted. Consequently, all the ten sockets were filled with HAP-hydrogel. Intraoral radiography was performed on the day of operation and 2, 4, 8 and 12 weeks post operation. The Kruskal-Wallis test and paired t-test were adopted for alveolar bone regeneration analysis. The results demonstrated that the radiographic grading, bone height measurement, and bone regeneration analysis were positively significant at all follow-up times compared to the day of operation. Moreover, the scanning electron microscopy with energy-dispersive X-ray spectroscopy imaging after immersion showed a homogeneous distribution of apatite formation on the hydrogel surface. Our investigation suggested that the HAP hydrogel effectively enhances socket regeneration in dogs with periodontitis and can be applied as a bone substitute for PSP in veterinary dentistry.

Augmentation Stability of Guided Bone Regeneration for Peri-Implant Dehiscence Defects with L-shaped Porcine-Derived Block Bone Substitute

Block bone substitutes have better augmentation stability for guided bone regeneration (GBR) than particulate bone substitutes. This study sought to determine whether GBR with an L-shaped porcine block bone (DPBM-C) differs from GBR with an L-shaped bovine block bone (DBBM-C) based on clinical, radiographic, and volumetric outcomes for peri-implant dehiscence defects. A total of 42 peri-implant defects were grafted with 20 L-shaped DPBM-C and 22 DBBM-C groups. The horizontal and vertical thicknesses of the augmented hard tissue were measured using sagittal cone-beam computed tomography, and the volumetric tissue change was evaluated by stereolithography image superimposition. Postoperative discomfort, early wound healing outcomes, and implant stability were also assessed. Among the clinical (subjective pain and swelling, wound dehiscence, membrane exposure, and periotest values), radiographic (changes in horizontal and vertical hard tissue thickness), and volumetric parameters of the L-shaped DPBM-C and DBBM-C groups during the healing period, only the periotest values showed a statistically significant difference (0.67 ± 1.19, p = 0.042). Within the limitations of this study, an L-shaped DPBM-C is not inferior to an L-shaped DBBM-C based on their clinical, radiographic, and volumetric outcomes for GBR of peri-implant dehiscence defects.

Effects of hyaluronic acid and deproteinized bovine bone mineral with 10% collagen for ridge preservation in compromised extraction sockets

BACKGROUND

The aim of this study was to evaluate the efficacy of deproteinized bovine bone mineral with 10% collagen (DBBM-C) soaked with hyaluronic acid (HA) for ridge preservation in compromised extraction sockets.

METHODS

Bilateral third, fourth premolars and first molar were hemisected, distal roots were extracted, and then combined endodontic periodontal lesion was induced in the remaining mesial roots. After 4 months, the mesial roots were extracted and the following four treatments were randomly performed: Absorbable collagen sponge (ACS), ACS soaked with HA (ACS+HA), ridge preservation with DBBM-C covered with a collagen membrane (RP), ridge preservation with DBBM-C mixed with HA and covered with a collagen membrane (RP+HA). Animals were sacrificed at 1 and 3 months following treatment. Ridge dimensional changes and bone formation were examined using microcomputed tomography, histology, and histomorphometry.

RESULTS

At 1 month, ridge width was significantly higher in the RP and RP+HA groups than in the ACS and ACS+HA groups, while the highest proportion of mineralized bone was observed in ACS+HA group. At 3 months, ridge width remained significantly higher in the RP and RP+HA groups than in the ACS and ACS+HA groups. ACS+HA and RP+HA treatments featured the highest proportion of mineralized bone and bone volume density compared with the other groups. No statistical difference was observed between ACS+HA and RP+HA treatments.

CONCLUSIONS

Ridge preservation with the mixture DBBM-C/HA prevented dimensional shrinkage and improved bone formation in compromised extraction sockets at 1 and 3 months.

Ridge preservation in maxillary molar extraction sites with severe periodontitis: a prospective observational clinical trial

OBJECTIVES

To assess alveolar bone changes and treatment modality alterations after ridge preservation on maxillary molar extraction sockets with severe periodontitis, compared to natural healing.

MATERIAL AND METHODS

Thirty-six maxillary infected-molar teeth either receiving ridge preservation (RG group) or undergoing natural healing (NT group) were investigated. Cone-beam computed tomography (CBCT) scanning was performed immediately after surgery (the baseline) and repeated 6 months later to measure the linear and volumetric changes of the sockets.

RESULTS

Based on radiographic measurements, alveolar bone width decreased by 1.58 ± 4.61 mm in the NT group but increased by 3.74 ± 4.17 mm in the RG group (p < 0.05). Significant increases in ridge height at the center of both the NT (7.54 ± 4.54 mm) and RG (9.20 ± 3.26 mm) groups were observed. Mean sinus pneumatization was 0.19 ± 0.45 mm in the RG group and 0.59 ± 0.63 mm in the NT group (p < 0.05). The relative increase in total ridge volume was 8.0% and 35.5% in the NT and RG group, respectively (p < 0.05). Implant placement with additional sinus augmentation procedure was performed in 16.7% of the RG group cases, whereas 50% in the NT group cases.

CONCLUSIONS

Ridge preservation in the maxillary molar extraction sockets with severe periodontitis can improve alveolar ridge dimensions and decrease the necessity of advanced regenerative procedures at implant placement compared to natural healing.

CLINICAL RELEVANCE

Ridge preservation on maxillary molar extraction sockets with severe periodontitis maintained the vertical bone height more efficiently and resulted in less need for sinus augmentation procedures at 6 months compared to natural healing.

Alveolar ridge regeneration in two-wall-damaged extraction sockets of an in vivo experimental model

Aim

To determine the healing outcome following grafting with deproteinized porcine bone mineral (DPBM) with or without collagen membrane coverage in two‐wall (both buccal and lingual)‐damaged extraction sockets.

Materials and methods

Distal roots of three mandibular premolars in six beagle dogs were extracted, and the whole buccal and lingual bony walls were surgically removed. Three treatment protocols were then applied according to the following group allocation: no graft (None), grafting DPBM (BG), and grafting DPBM with coverage by a collagen membrane (BG + M). Two observational periods (2 and 8 weeks) were used with the split‐mouth design, and quantitative and qualitative analyses were performed by microcomputed tomography and histology.

Results

The dimensions of the alveolar ridge at both grafted sites (BG and BG + M) remained similar to those of the pristine ridge in the histologic and radiographic analyses, whereas the ungrafted sites (None) collapsed both vertically and horizontally. Both grafting protocols produced substantial bony regeneration, but the addition of a covering membrane enhanced the proportion of mineralized tissue within the augmented area, and the BG + M group also showed a significantly larger area of regenerated ridge than the None group (p < .05).

Conclusions

Bone grafting with collagen membrane can maintain the alveolar ridge dimensions with substantial bone regeneration in a two‐wall‐damaged extraction socket.

What grafting materials produce greater alveolar ridge preservation after tooth extraction? A systematic review and network meta-analysis

A systematic review and network meta-analysis was conducted to compare different bone-substitute materials used for alveolar ridge preservation after tooth extraction. The electronic search was carried out on Embase, PubMed, Cochrane Library, Web of Science, Scopus, LILACS, and grey literature up to March 22, 2020 (registration number INPLASY202030005). Only randomized controlled trials were included to answer the following PICOS question: 'What grafting materials produce greater alveolar ridge preservation after tooth extraction?' The primary outcomes were the alveolar width resorption 1 mm below the alveolar crest and buccal height resorption in millimeters. Of the 4379 studies initially identified, 31 studies involving 1088 patients were included in the quantitative analyses. Out of 25 revised biomaterials, eight showed a statistically significant difference compared with unassisted healing in both alveolar width and height measurements (mean width differences: ApatosⓇ, 2.27 [1.266-3.28]; Bio-OssⓇ, 0.88 [0.33-1.42]; Bio-Oss CollⓇ, 0.53 [0.04-1.01]; Bond-apatiteⓇ, 2.20 [1.30-3.11]; freeze-dried bone allograft, 1.35 [0.44-2.26]; Gen-OsⓇ, 1.90 [0.60-3.20]; platelet-rich fibrin, 1.66 [0.66-2.67]; and MP3Ⓡ, 2.67 [1.59-3.75]). Overall, xenograft materials should be considered as among the best of the available grafting materials for alveolar preservation after tooth extraction.

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.

Extraction socket preservation

Extraction socket preservation (ESP) is widely performed after tooth extraction for future implant placement. For successful outcome of implants after extractions, clinicians should be acquainted with the principles and indications of ESP. It is recommended that ESP be actively implemented in cases of esthetic areas, severe bone defects, and delayed implant placement. Dental implant placement is recommended at least 4 months after ESP.

Soft Tissue Dimensions Following Tooth Extraction in the Posterior Maxilla: A Randomized Clinical Trial Comparing Alveolar Ridge Preservation to Spontaneous Healing

Background: To assess the soft tissue dimension following tooth extraction and alveolar ridge preservation in the posterior maxilla compared to spontaneous healing. Methods: Thirty-five patients randomly assigned to alveolar ridge preservation (ARP) and spontaneous healing (SH) after maxillary molar extraction. The crestal, buccal, and palatal gingival thickness at 6 months was measured around virtually placed implant fixtures using superimposed cone-beam computed tomography and intraoral scan taken at 6 months. Buccal mucogingival junction (MGJ) level change over 6 months was estimated using intraoral scans obtained at suture-removal and 6 months. Results: The crestal gingiva was significantly thinner in group ARP (−1.16 mm) compared to group SH (p < 0.05). The buccal and palatal gingiva was significantly thinner at the implant shoulder (IS) level in group ARP (buccal: −0.75 mm; palatal: −0.85 mm) compared to group SH (p < 0.05). The thickness at 2 mm below the IS of both sides and the buccal MGJ level change were similar in both groups (p > 0.05). Conclusions: ARP in the posterior maxilla resulted in a thinner soft tissue on top of and at the prospective level of the implant shoulder at 6 months. The buccal MGJ level changed minimal for 6 months in both groups.

Histological comparison of different compressive forces on particulate grafts during alveolar ridge preservation: a prospective proof-of-concept study

Purpose

The aim of this study was to determine the impact of different compressive forces on deproteinized bovine bone mineral (DBBM) particles covered by native bilayer collagen membrane (NBCM) during alveolar ridge preservation (ARP) in the molar area, and to identify any histomorphometric and clinical differences according to the compressive force applied.

Methods

Sockets were filled with DBBM after tooth extraction, and different compressive forces (30 N and 5 N, respectively) were applied to the graft material in the test (30 N) and control (5 N) groups. The DBBM in both groups was covered with NBCM in a double-layered fashion. A crossed horizontal mattress suture (hidden X) was then made. A core biopsy was performed using a trephine bur without flap elevation at the implant placement site for histomorphometric evaluations after 4 months. The change of the marginal bone level was measured using radiography.

Results

Twelve patients completed the study. The histomorphometric analysis demonstrated that the mean ratios of the areas of new bone, residual graft material, and soft tissue and the implant stability quotient did not differ significantly between the groups (P>0.05). However, the mean size of the residual graft material showed a significant intergroup difference (P<0.05).

Conclusions

The application of 2 compressive forces (5 N, 30 N) on particulate DBBM grafts during open-healing ARP in the posterior area led to comparable new bone formation, implant feasibility and peri-implant bone level.

New Oral Surgery Materials for Bone Reconstruction-A Comparison of Five Bone Substitute Materials for Dentoalveolar Augmentation

This article presents a comparison of bone replacement materials in terms of their ability to produce living bone image at the place of their implantation. Five bone replacement materials are compared (Osteovit-porous collagen, Cerasorb Foam-collagen scaffolding of synthetic β tricalcium phosphate, Osbone-synthetic hydroxyapatite, Endobone-deproteinized bovine-derived cancellous bone hydroxyapatite, and Cerasorb-synthetic β tricalcium phosphate). Intraoral radiographs are taken immediately after implantation and 12 months later. The texture analysis was performed to assess (texture index, TI) the level of structure chaos (entropy) in relation to the presence of longitudinal elements visible in radiographs (run length emphasis moment). The reference ratio of the chaotic trabecular pattern (Entropy) to the number of longitudinal structures, i.e., trabeculae (LngREmph), is 176:100 (i.e., 1.76 ± 0.28). Radiological homogeneity immediately after the implantation procedure is a result of the similar shape of its particles (Osbone, Endobone and Cerasorb) or radiolucency (Osteovit, Cerasorb Foam). The particles visible in radiographs were similar in the LngREmph parameters applied to the reference bone, but not in the co-occurrence matrix features. The TI for Osteovit during a 12-month follow-up period changed from 1.55 ± 0.26 to 1.48 ± 0.26 (p > 0.05), for Cerasorb Foam from 1.82 ± 0.27 to 1.63 ± 0.24 (p < 0.05), for Osbone from 1.97 ± 0.31 to 1.74 ± 0.30 (p < 0.01), and for Endobone from 1.86 ± 0.25 to 1.84 ± 0.25 (p > 0.05), The observed structure in the radiological image of bone substitute materials containing calcium phosphates obtains the characteristics of a living bone image after twelve months.

A reduced healing protocol for sinus floor elevation in a staged approach with deproteinized bovine bone mineral alone: A randomized controlled clinical trial of a 5-month healing in comparison to the 8-month healing

PURPOSE

To investigate the feasibility of reducing the healing time of maxillary sinus floor elevation (MSFE) by a two-stage approach using deproteinized bovine bone mineral (DBBM) alone, based on clinical, histomorphometric, and microradiographic evaluations.

MATERIALS AND METHODS

Twenty consecutive cases with an atrophic posterior edentulous maxilla were randomly assigned to two groups at a ratio of 1:1. The lateral window approach to MSFE with DBBM alone was followed by an 8-month bone-healing period in the control group compared to 5 months in the test group. During implant placement, bone biopsies were harvested from implant osteotomy sites for micro-computed tomography (CT), histological, and histomorphometric evaluations. Cone beam CT (CBCT) scans were performed before and immediately after MSFE and after the bone-healing periods. The implant stability quotient (ISQ) was measured sequentially at implant placement and 1, 3, and 6 months thereafter.

RESULTS

The histomorphometric and microradiographic results showed no significant differences in new bone formation on the augmented sinus floor between the two groups (all Ps > .05), except that trabecular thickness was significantly reduced and trabecular separation significantly increased in the test group (both Ps < .05). The ISQs of both groups increased continuously after implant placement, but the difference was not significant between the groups at each time point. CBCT analyses showed that the extent of volumetric loss was comparable after bone healing for 5 and 8 months (P > .05).

CONCLUSIONS

Within the limitations of this study, the bone-healing time of MSFE with DBBM alone for staged implant placement could be reduced to 5 months instead of 8 or 9 months, based on the histomorphometric, microradiographic, and clinical outcomes; however, impact on long-term implant survival remains unknown and needs further investigation with long-term follow-ups.

Ridge reconstruction in damaged extraction sockets using tunnel β-tricalcium phosphate blocks: A 6-month histological study in beagle dogs

OBJECTIVE

The present study aimed to evaluate the histological outcome of tunnel β-TCP blocks grafting in extraction sockets missing the buccal bone wall, after 6 months of healing.

BACKGROUND

Tunnel β-tricalcium phosphate (β-TCP) blocks made of randomly organized tunnel-shaped β-TCP ceramics appeared promising for alveolar ridge preservation in tooth extraction sockets missing the buccal bone, in a previous study in dogs, with a 2-month healing time.

METHODS

In six beagle dogs, the maxillary first premolars were extracted and the buccal bone was surgically removed to create bone defects of 4 mm (mesio-distal) × 5 mm (apico-coronal) × 4 mm (bucco-palatal). Thus, extraction sockets missing the buccal bone plate were grated with tunnel β-TCP blocks (test) or left empty for spontaneous healing (control). Histology/histomorphometry was performed after 6 months of healing.

RESULTS

The horizontal bucco-palatal width of the alveolar ridge was significantly greater at test sites than at control sites. The amount of mineralized tissue was greater at test sites (57.8% ± 11.1%) than at control sites (28.9% ± 8.5%), while the amount of connective tissue was significantly greater at control sites (41.7% ± 6.4%) than at test sites (19.6% ± 9.2%). No significant difference was found between sites in terms of basic multicellular units and bone marrow. Residual β-TCP at test sites was 5.8% ± 3.2%.

CONCLUSION

Grafting with tunnel β-TCP block significantly limited the resorption of the alveolar ridge at extraction sockets missing the buccal bone compared with sites left to heal spontaneously, even after 6-month follow-up.

Cone-beam computed tomographic analysis of the alveolar ridge profile and virtual implant placement for the anterior maxilla

Purpose

To analyze the ridge profile of the anterior maxilla using cone-beam computed tomography and to assess the clinical significance of the ridge profile by performing virtual implant placement.

Methods

Thirty-two cone-beam computed tomography scans of anterior maxillae were included. For each tooth, a vertical line was made along the longitudinal axis, and 3 horizontal lines at 1-, 3-, and 5-mm levels below the labial bone crest were drawn perpendicularly to the vertical reference. At these levels, the thickness of the alveolar ridge (RT), and the labial (LT) and palatal bone plate (PT) were measured. Then, virtual implant placement using standard and tapered implants was performed. A generalized linear mixed model was used for statistical analysis.

Results

The teeth were located labially based on the proportion of LT and PT with respect to RT. At the 1-mm level, the value of LT was between 1.0±0.4 mm for central incisors and 1.3±0.6 mm for canines. A large number of teeth had area(s) with less than 1-mm-thick labial bone between the 1- and 5-mm levels below the crest. The mean PT was generally thicker than the LT in all tooth types. The greatest mean value of labial concavity was observed for canines, compared to other tooth types. Men had a greater RT than did women, but had a comparable LT. Less apical fenestration was observed when tapered implants were used.

Conclusions

Most teeth in the anterior maxilla had a thin labial bone plate, with no significant difference between sexes. Tapered implants may be advantageous for the anterior maxilla.

Bone regeneration using three-dimensional hexahedron channel structured BCP block in rabbit calvarial defects

The purpose of this study is to evaluate the efficacy of bone regeneration and volume maintenance of the three-dimensional (3D) structured biphasic calcium phosphate (BCP) block with porous hexahedron channels in a rabbit calvarial model. In this work, four circular defects (diameter: 8 mm) in calvarium of rabbits were randomly assigned to (1) negative control (control), (2) 3D hexahedron channel structured BCP block, (3) deproteinized bovine bone mineral particle, and (4) deproteinized porcine bone mineral particle. Animals were euthanized at 2 (n = 5) and 8 weeks (n = 5). Outcome measures included micro-computed tomography (CT) and histomorphometrical analysis. Results indicated that in micro-CT, BCP group showed the highest new bone volume with significant difference compared to control (p = 0.008) at 8 weeks. Histomorphometrically, total augmented area of BCP group was the highest with significant difference compared to control (p = 0.008) at 8 weeks. BCP group also maintained total volume of the original defect without collapsing. BCP block with 3D hexahedron channel structure seems to have favorable osteogenic and volume maintaining ability and highly porous structure might attribute to new bone formation. Further studies regarding the optimal internal structure and porosity of the BCP block bone substitute are needed. © 2019 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 2254-2262, 2019.

Alveolar ridge regeneration of damaged extraction sockets using deproteinized porcine versus bovine bone minerals: A randomized clinical trial

Backgrounds

Clinical benefits in bone grafting of intact extraction socket have been widely known, but limited evidence is available for the procedure in damaged extraction sockets due to periodontal disease.

Purpose

This study aimed to determine the dimensional alteration of alveolar ridge following bone grafting of damaged extraction sockets, and compare the outcomes of using deproteinized bovine (DBBM) versus porcine bone mineral (DPBM) in the damaged sockets.

Materials and Methods

One hundred patients (n = 50 for each group) with periodontitis‐induced damaged extraction socket were included in this randomized, single‐blind trial. After removal of tooth and granulation tissue, sites were grafted with either DBBM (DBBM group) or DPBM (DPBM group), and covered with collagen membrane. Linear/volumetric analyses of hard and soft‐tissue dimensions were performed on reconstructed/superimposed computed tomography and scanned cast images, taken immediately and 4 months after surgery.

Results

The two groups showed comparable hard tissue augmentation with minimal reductions in the grafted volume, as well as in vertical (1.22 ± 2.16 and 1.45 ± 1.92 mm for DPBM and DBBM group, respectively) and horizontal (1.43 ± 3.40 and 1.83 ± 2.85 mm on the central section, respectively) dimensions at 4 months after surgery. However, several cases showed large variations in maintenance of the grafted volume. None of the measured parameters in hard and soft tissue dimensions differed significantly between DBBM and DPBM sites.

Conclusions

DBBM and DPBM can comparably augment damaged extraction sockets with minimal postoperative reduction of the grafted volume. However, the large variations in the results should be further evaluated for application in routine dental clinics.