Accelerating Socket Repair via WNT3A Curtails Alveolar Ridge Resorption

Background: Alveolar ridge resorption still continues to be a problem in oral surgery. Cause of bone resorption is including tooth extraction, periodontal disease and inflammatory periapical pathologies. Various methods and materials have been suggested to minimize this resorption. Aim: Goal of this case report is to present alveolar ridge preservation (ARP) following horizontally fractured maxillary lateral incisor with allograft in the aesthetic zone. Case presentation: 30-year-old female patient with fractured tooth was treated by grafting and insertion dental implant. Fractured tooth extraction was performed and extraction socket augmentation was performed by allograft and covered with collagen membrane. Augmented area was treated with bone-level implant. Definitive prosthesis single-tooth porcelain-fused-to-zirconia restorations were fabricated. Conclusions: Before implant insertion, extraction and grafting socket procedure is appropriate treatment for of fractured teeth with granulation tissue.

Leucocyte- and platelet-rich fibrin (L-PRF) has been tested for enhancing alveolar ridge preservation (ARP), but little is known about the local release profile of growth factors (GF), and the clinical equipoise related to its efficacy remains. This study compared the patterns of GF release, early soft tissue healing, and alveolar ridge resorption following unassisted healing and L-PRF application in non-molar extraction sockets. Atraumatic tooth extraction of two hopeless teeth per patient was followed by unassisted healing or L-PRF placement to fill the socket in 18 systemically healthy, non-smoking subjects. This intra-individual trial was powered to assess changes in horizontal alveolar ridge dimensions 1 mm below the crest of alveolar bone. GF concentrations in wound fluid were assessed with a multiplex assay at 6, 24, 72, and 168 h. Early healing was evaluated with the wound healing index and changes in soft tissue volumes on serial digital scans. Hard tissue changes were measured on superimposed CBCT images after 5months of healing. L-PRF resulted in higher GF concentrations in wound fluid (WF) than in the control, but no differences in release patterns or time of peak were observed. No inter-group differences in early healing parameters were observed. Alveolar bone resorption was observed in both groups. No significant inter-group differences were observed in hard tissue healing 1, 3, or 5 mm apical to the original bone crest or in the ability to digitally plan a prosthetically guided implant with or without bone augmentation. L-PRF increased the GF concentrations in WF of extraction sockets without shifting the pattern observed in unassisted healing, while the increased delivery did not translate into clinical benefits in early wound healing or ARP. The current findings question the assumption that increased local concentrations of GF by L-PRF translate into improved clinical outcomes. Additional definitive studies are needed to establish the benefits of L-PRF in ARP (ClinicalTrials.gov NCT03985033).

Alveolar ridge resorption after tooth extraction is a frequently observed phenomenon that may either decrease the predictability of dental implant placement or impair the final esthetic results.1,2 Better understanding of the biologic process behind extraction-socket healing has led to the development of techniques to preserve the natural architecture of the alveolus after extraction, such as immediate implant placement in fresh sockets and the use of osseous graft materials.3It is now known that resorption will especially target the buccal plate if the socket is not grafted immediately after dental extraction,3,4 thereby increasing the risk for facial soft tissue recession.4 Even when minimal, such resorption usually has significant adverse clinical effects, particularly in the esthetic zone. Despite successful osseointegration of a dental implant, an anterior implant restoration may be judged to be a failure if the soft tissue appearance is poor.5–8 Surgical techniques meant to preserve natural bone and soft tissue contours after tooth extraction are thus of great interest to contemporary clinicians, especially true if an implant is placed and provisionalized immediately after tooth extraction.Numerous studies have focused on immediate functional loading of dental implants to minimize the delay between the surgical and prosthetic treatment phases.9,10 This technique is increasingly being applied when replacing teeth in the maxillary anterior region, where esthetic outcomes are important.11–17 However, some studies12,15,16 have reported that recession of the marginal peri-implant mucosa may occur after immediate implant placement. This recession, in turn, may adversely affect the final esthetic outcome.Factors that have been reported to influence the frequency and extent of marginal mucosal recession include the tissue biotype,17 the condition and thickness of the facial bone,18 and the orofacial position of the implant shoulder.19,20 Connecting a provisional crown immediately after implant insertion8,21 and grafting of the facial peri-implant marginal defect with bone or bone substitutes21–23 also have been cited as factors. In addition to these parameters, an experimental study24 showed that the facial socket wall, which is composed almost entirely of bundle bone, may be susceptible to resorption in the vertical and horizontal planes. Such crestal bone resorption may lead to recession of the facial marginal mucosa.Any alteration of the soft or hard tissues may impair the final esthetic outcome of immediately loaded implants in the anterior area. To better preserve the alveolar ridge and maintain optimal soft tissue contours, we previously introduced a novel buccal plate preservation (BPP) technique.25,26This simple surgical technique may help to prevent recession of the facial wall of the extraction socket without interfering with the healing process. It involves placement of particulate bone-graft material underneath the soft tissues in a surgically created pouch adjoining the buccal plate. It thus maintains optimal soft tissue contours and predictably provides a solid base for optimal esthetics and functional replacement of a missing tooth. Although we originally used this technique in the wake of tooth extraction when a delayed implant placement was planned, it also can be used effectively in conjunction with immediate implant placement and provisionalization, as the following case report illustrates.The 66-year-old male patient was referred by his dentist for extraction of a left central incisor whose root had fractured (Figures 1 and 2). The treatment plan included rehabilitation with an implant-supported restoration with immediate placement after extraction and immediate provisionalization. The patient's past medical and social history were noncontributory, and he had good oral hygiene.The incisor was extracted atraumatically in 2 pieces. The socket was thoroughly debrided to remove residual granulation tissue (Figure 3). A straight periosteal elevator was used to carefully perform limited soft tissue dissection in a full-thickness manner, creating a pouch on the vestibular aspect of the middle of the socket facial to the buccal plate (Figure 4). This dissection started coronally, at the marginal bony ridge of the extraction socket, and slowly proceeded in the apical direction, using small mesiodistal movements. Extreme care was paid to avoid tearing the soft tissue. Once the dissection had advanced beyond the mucogingival line to approximately two-thirds the depth of the socket, a curved periosteal elevator was used to expand the pouch in the mesiodistal direction. The goal was to stretch the soft tissues away from the underlying bony plate (Figure 5), and no attempts were made to decorticate the buccal plate.Granules (500-1000 μm) of bovine sintered xenograft (Endobon Xenograft Granules, BIOMET 3i, Palm Beach Gardens, Fla) were rehydrated with saline and placed in the pouch using a syringe. The bone-graft material was then compressed with a small surgical curette, and more graft material was added and compressed until adequate filling of the pouch was achieved without overstretching the soft tissues. The quantity used was approximately 0.1 cm3 and normally is <0.2 cm3, regardless the size of the tooth. Care was taken to avoid the migration of the graft material too far apically, where the mucosa is more flexible and thin, although should migration occur, the graft material can be repositioned using manual pressure. The final appearance of the soft tissue should exaggerate the appearance of the root eminence of the tooth before extraction. This is done to counteract some dispersion and exfoliation of the graft (Figure 6).A 13 mm length × 4-mm-diameter tapered implant (BIOMET 3i, Palm Beach Gardens) was then placed according to the manufacturer's protocol, engaging the native bone above the alveolus, slightly palatal from the buccal plate (Figure 7). Additional xenograft material was placed in the gap between the buccal bone and the implant surface. After the completion of the surgical procedure, the position of the implant was transferred to a model with an impression pick-up that was connected to the surgical stent with self-curing resin. A healing abutment was then screwed to the implant, and the patient was dismissed with instructions to consume only a liquid diet and return in the afternoon for delivering of the provisional.A custom abutment and resin crown were fabricated immediately and delivered to the patient (Figure 8) a few hours after the surgical procedure. No sutures were required, and no attempt was made to coronally reposition the flap. The patient was maintained on the liquid diet for the next 2 wk. Chlorhexidine gluconate oral rinse also was prescribed for 2 wk to enhance plaque control. After 3 months, the final restoration was delivered (Figures 9 and 10).The appearance and the contours of the ridge were well maintained, after extraction. A convexity on the buccal aspect of the extraction area, giving an illusion of root eminence, was achieved, laying the ground for a good functional and esthetic replacement of the missing tooth with an implant-supported prosthesis.Extraction sockets are self-healing defects. In a relatively short time, the void left by the root of the extracted tooth is filled by new bone.1 As this biophysiologic phenomenon occurs, however, the architecture of the edentulous ridge may change adversely due to buccal bone resorption. Such changes may jeopardize implant placement or lead to an unfavorable esthetic final result.2 Although the degree of bone loss is neither certain nor constant, varying among individuals and anatomic situations, most alveolar width and height resorption occurs in the first 6 months after extraction.2When clinicians face situations where immediate implant placement is not indicated, two options have existed: (1) allow the socket to heal naturally without grafting or (2) graft the socket. Natural healing without grafting increases the risk of hard tissue loss, soft tissue loss, or both, especially on the buccal plate due to resorption. Grafting the socket requires a longer healing time before implant placement.We have developed a third option, namely, grafting not inside the socket but externally to the buccal plate in a surgically created pouch.25,26 This technique can only be applied when the natural architecture is intact and the buccal plate is present. In a 4-wall intact socket, this approach is aimed at optimizing the ability of the bone graft to improve regeneration and maintain or improve labial and buccal contours without interfering with the natural healing capability of the alveolus after extraction. The rationale behind it is that slowly resorbing or nonresorbing particles of bovine xenograft get incorporated in the soft tissues, thereby preventing recession and enhancing the soft tissue appearance of the edentulous ridge.Bovine xenograft has been shown to have a very low resorption rate in many different sites. This tendency may be regarded as less than ideal in potential implant-placement sites, but according to several studies, once incorporated in bone, the particles may help prevent resorption of the newly regenerated area in the long term.27,28 It also has been shown that in the esthetic area, regenerating the facial aspect of the buccal plate with a nonresorbable membrane and bovine xenograft may prevent bone remodeling from taking place at the head of the implant and causing soft tissue recession and other esthetic complications.18,29 The latter approach consists of a full guided bone regeneration procedure aiming to overbuild the bone around the neck of the implant and thus prevent bone resorption. This procedure is requiring the membrane removal and a later stage.The possibility of immediately connecting a provisional restoration to implants placed into fresh extraction sites has been extensively investigated.30–37 Some case reports have found a 100% 12-month survival rate for immediate, nonfunctional restorations of single-tooth postextraction implants.30–32 Favorable peri-implant tissue responses also have been reported around such implants, along with results that were clinically and radiographically comparable to those achieved after a conventional delayed protocol. Several uncontrolled prospective studies also have investigated the immediate functional loading of postextraction implants in edentulous mandibles33–35 or in partially edentulous sites.34Connecting a provisional crown immediately after implant insertion8,21 has been reported among the many factors that can influence the frequency and extent of marginal mucosal recession. In addition to these factors, an experimental study24 showed that the facial socket wall, which is composed almost entirely of bundle bone, may be susceptible to resorption in the vertical and horizontal planes. Such crestal bone resorption may lead to recession of the facial marginal mucosa. Any alteration of the soft or hard tissues may impair the final esthetic outcome of immediately loaded anterior implants.In 4-wall extraction sockets, the buccal plate preservation technique described in this article may help to maintain or improve the appearance and contours of the ridge after tooth extraction, laying the ground for a good functional and esthetic replacement of the missing tooth with an implant-supported prosthesis. The procedure also can enhance the soft tissue appearance when implant placement and loading are indicated immediately after tooth extraction. Although the preliminary results of using this technique are promising, further investigation is warranted to confirm its efficacy; understand the biology underlying it; and identify factors that may influence it, such as the thickness of buccal plate after extraction, presence of contiguous teeth, type of bone graft with or without membrane, and position of the implant.

The placement of different graft materials and/or the use of occlusive membranes to cover the extraction socket entrance are techniques aimed at preserving/reducing alveolar ridge resorption. The use of grafting materials in fresh extraction sockets has, however, been questioned because particles of the grafted material have been found in alveolar sockets 6-9 months following their insertion. The aims of the study were to (i). evaluate whether alveolar ridge resorption following tooth extraction could be prevented or reduced by the application of a bioabsorbable polylactide-polyglycolide sponge used as a space filler, compared to natural healing by clot formation, and (ii). evaluate histologically the amount and quality of bone tissue formed in the sockets, 6 months after the use of the bioabsorbable material. Thirty-six patients, undergoing periodontal therapy, participated in this study. All patients were scheduled for extraction of one or more compromised teeth. Following elevation of full-thickness flaps and extraction of teeth, measurements were taken to evaluate the distance between three landmarks (mesio-buccal, mid-buccal, disto-buccal) on individually prefabricated stents, and the alveolar crest. Twenty-six alveolar sockets (test) were filled with a bioabsorbable polylactide-polyglycolide acid sponge (Fisiograft), while 13 sockets (controls) were allowed to heal without any filling material. The flaps were sutured with no attempt to achieve primary closure of the surgical wound. Re-entry for implant surgery was performed 6 months following the extractions. Thirteen biopsies (10 test and three control sites) were harvested from the sites scheduled for implant placement. The clinical measurements at 6 months revealed, in the mesial-buccal site, a loss of bone height of 0.2 mm (1.4 SD) in the test and 0.6 mm (1.1 SD) in the controls; in the mid-buccal portion a gain of 1.3 mm (1.9 SD) in the test and a loss of 0.8 mm (1.6 SD) in the controls; and in the distal portion a loss of 0.1 mm (1.1 SD) in the test and of 0.8 (1.5 SD) mm in the controls. The biopsies harvested from the test sites revealed that the new bone formed at 6 months was mineralized, mature and well structured. Particles of the grafted material could not be identified in any of the 10 test biopsies. The bone formed in the control sites was also mature and well structured. The results of this study indicate that alveolar bone resorption following tooth extraction may be prevented or reduced by the use of a bioabsorbable synthetic sponge of polylactide-polyglycolide acid. The quality of bone formed seemed to be optimal for dental implant insertion.

Following tooth extraction, the bone structure is prone to atrophic changes. Alveolar ridge resorption can compromise subsequent implant treatment not only at the extraction site itself but also by affecting the bone support of adjacent teeth. Various techniques, including the use of bone graft materials or autologous blood concentrates for ridge or socket preservation, aim to counteract this process. The efficacy of such methods can be evaluated non-invasively through radiological analysis of the treated region. However, existing radiological evaluation methods often focus only on isolated areas of the extraction socket, limiting their accuracy in assessing overall bone regeneration. This study introduces a novel, non-invasive, and semi-automated image-based analysis method that enables a more comprehensive evaluation of bone preservation using CBCT data. Developed with the open-source software "Fiji" (v2.15.0; based on ImageJ), the approach assesses bone changes at multiple horizontal and vertical positions, creating a near three-dimensional representation of the resorptive process. By analyzing the entire region around the extraction socket rather than selected regions, this method provides a more precise and reproducible assessment of alveolar ridge preservation. Although the approach requires some processing time and focuses exclusively on radiological evaluation, it offers greater accuracy than conventional methods. Its standardized and objective nature makes it a valuable tool for clinical research, facilitating more reliable comparisons of different socket preservation strategies.

Background: The socket preservation technique involves filling the bone defect created after tooth extraction with a bone substitute material. This helps to reduce bone resorption of the post-extraction alveolar ridge. Various types of bone substitute biomaterials are used as augmentation materials, including autogeneic, allogeneic, and xenogeneic materials. The purpose of this study was to evaluate changes in alveolar ridge dimensions and alterations of optical bone density in sockets grafted with two different biomaterials. Additionally, bone biopsies taken from the grafted sites underwent histological evaluation. Methods: This study enrolled 10 generally healthy patients, who were divided into two equal groups. Patients in the first group were treated with an allogeneic material (BIOBank®, Biobank, Paris, France), while patients in the second group were treated with an xenogeneic material (Geistlich Bio-Oss®, Geistlich Pharma AG, Wolhusen, Switzerland). Tooth extraction was performed, following which the appropriate material was placed into the debrided socket. The material was secured with a collagen membrane (Geistlich Bio-Gide®, Geistlich Pharma AG, Wolhusen, Switzerland) and sutures, which were removed 7 to 10 days after the procedure. Micro-CBCT examinations were performed, for the evaluation of alveolar ridge dimensions and bone optical density, at 7–10 days and six months after the procedure. Bone trepanbiopsy was performed simultaneously to the implant placement, six months after socket preservation. The retrieved biopsy was subjected to histological examination via hematoxylin and eosin (H&E) staining and Masson’s trichrome staining. Results: The results showed that the allogeneic material was more effective in preserving alveolar buccal height and was probably more rapidly transformed into the patient’s own bone. Sockets grafted with the xenogeneic material presented higher optical bone density after six months. Both materials presented similar effectiveness in alveolar width preservation. Conclusions: Based on the outcomes of this study, it can be concluded that both materials are suitable for the socket preservation technique. However, the dimensional changes in the alveolar ridge and the quality of the newly formed bone may vary depending on the type of biomaterial used.

BackgroundDifferent techniques and materials such as bone grafts and bioactive agents have been used for alveolar ridge augmentation in extraction sockets with a defective wall, there is not a specific material or technique that has resulted in superior outcomes or prevented total bone loss.ObjectivesThis clinical study aims to evaluate radiographically the effectiveness of using bovine xenograft with platelet-rich fibrin (PRF) membrane on vertical and horizontal alveolar ridge dimensional changes following tooth extraction that are complicated by buccal bone loss.Materials and methodsThis study was conducted in Egypt on fourteen patients with a single posterior tooth indicated for extraction. A preoperative cone-beam computed tomography (CBCT) scan confirmed more than 50% loss in buccal bone in each tooth. Extraction sockets were packed with minced PRF clots mixed with a bovine xenograft. Each extraction socket was sealed by PRF membranes. CBCT scans, performed before tooth extraction and after 6 months, were used to assess alveolar ridge changes both vertically and horizontally.ResultsThere was a significant gain in the buccal and middle of the extraction socket bone height, recording 86.01% (6.33 mm) and 206.45% (9.6 mm), respectively. There was an insignificant bone loss in the lingual bone height and width, recording − 8.49% (-1.06 mm) and − 13.39% (1.05 mm), respectively. The results also showed a non-significant decrease in alveolar bone density (-14.06%) between pre-operative bone present apical to the extraction socket and newly formed bone inside the socket.ConclusionsRidge preservation/augmentation techniques using a bone graft mixed with PRF and covered by PRF membranes in fresh extraction sockets complicated by the loss of buccal bone result in buccal bone augmentation and a reduction in horizontal and vertical ridge collapse after tooth extraction.Clinical relevanceThe bovine xenograft in conjunction with PRF can be used immediately after extraction for ridge preservation, providing adequate bone width and height for implant placement.

The present study intended to evaluate the effect of simvastatin-loaded nanomicelles (SVNs) on promoting new bone formation and reducing alveolar ridge resorption at the tooth extraction sites at the early healing of the extraction sockets. SVNs were synthesized using a dialysis method. The rabbit tooth extraction model was established, SVNs and simvastatin (SV) were loaded on gelatin sponge and inserted into the extraction socket. CBCT scans were performed at 0, 2, and 4weeks postoperatively to evaluate bone formation and alveolar ridge absorption in the extraction sockets. And all the animals were sacrificed and the mandibles were harvested. And HE staining and Masson staining were used for histological evaluation of the bone formation in the extraction sockets. Radiographic evaluation showed that compared with the blank control group, at 2 and 4weeks after extraction, SVNs increased the new bone density in the extraction sockets by 75.7% and 96.5%, and reduced the absorption rate of alveolar ridge length at the extraction sites by 60.8% and 49.1%, respectively. Histological evaluation showed that SVNs significantly improved the maturation of new bone tissue in the extraction sockets. SVNs can significantly accelerate healing and effectively reduce the absorption of alveolar ridge at the extraction sites in the early stage of tooth extraction socket healing.

A Review on Alveolar Ridge Preservation Following Tooth Extraction

Alveolar bone undergoes volumetric changes after extraction due to physiologic bone remodeling. The amount of alveolar bone available during prosthodontic treatment can affect the esthetic outcome of the treatment and make implant placement challenging. Socket preservation techniques are advocated postextraction to maintain the bone's vertical and horizontal alveolar bone dimensions and prevent its atrophy. This review is oriented toward a clinician, describing the different materials and techniques in practice today for socket preservation. A variety of methods have been studied as a means to stop alveolar ridge resorption. While immediate implant placement was recommended as a socket preservation technique, clinical trials have not demonstrated favorable results. The main techniques favored by clinicians today involve bone grafts, bone substitutes, barrier membranes, and combinations thereof. As with periodontal defects, these materials show favorable outcomes in alveolar bone regeneration and ridge preservation. Tooth bone grafts, both autogenous and allogenous, have been recommended recently for ridge preservation as they are chemically similar to bone and can induce osteogenesis. The use of autologous platelet concentrates has yielded contradictory results in studies. Cutting-edge approaches entail using growth factors and tissue engineering concepts. While these strategies are still in the development stages, it has peerless potential in preserving and regenerating alveolar bone. Alveolar ridge resorption is an unavoidable physiological process after extraction and leads to severe bone deficiencies, affecting esthetics. These changes in alveolar ridge dimensions make implant placement difficult and affect the longevity of the implant. Clinical intervention can prevent alveolar bone resorption and preserve the ridge. Bone grafts and substitutes including concentrates remain the best choices in ride preservation. The use of growth factors and tissue engineering concepts requires further clinical trials before widespread use in clinical practice.

It is well established that tooth extraction is followed by a reduction of the buccolingual as well as the apicocoronal dimension of the alveolar ridge. Different measures have been taken to avoid this bone modelling process, such as immediate implant placement and bone grafting, but in most cases with disappointing results. One fundamental principle of bone physiology is the adaptation of bone mass and bone structure to the levels and frequencies of strain. In the present article, it is shown that the reduction of the alveolar ridge dimensions after tooth extraction is a natural consequence of this physiological principle.

The primary objective of this study was to determine the association between the size of the void established by using two different implant configurations and the amount of buccal/palatal bone loss that occurred during 16 weeks of healing following their installation into extraction sockets. The clinical trial was designed as a prospective, randomized-controlled parallel-group multicenter study. Adults in need of one or more implants replacing teeth to be removed in the maxilla within the region 15-25 were recruited. Following tooth extraction, the site was randomly allocated to receive either a cylindrical (group A) or a tapered implant (group B). After implant installation, a series of measurements were made to determine the dimension of the ridge and the void between the implant and the extraction socket. These measurements were repeated at the re-entry procedure after 16 weeks. The study demonstrated that the removal of single teeth and the immediate placement of an implant resulted in marked alterations of the dimension of the buccal ridge (43% and 30%) and the horizontal (80-63%) as well as the vertical (69-65%) gap between the implant and the bone walls. Although the dimensional changes were not significantly different between the two-implant configurations, both the horizontal and the vertical gap changes were greater in group A than in group B. Implant placement into extraction sockets will result in significant bone reduction of the alveolar ridge.

After tooth extraction the alveolar bone undergoes a remodeling process resulting in an overall bone volume reduction. Several studies showed that socket grafting limits the alveolar ridge remodeling. Furthermore studies showed that the grafting material is involved in a partial remodeling process and that the remodeling time extends for years. Aim of the present study was to evaluate the correlation between graft remodeling and volumetric ridge alteration. Materials and Methods Seven extraction sockets were grafted with Bio-Oss collagen and 8 extraction sockets were left untreated. At baseline, 3 and 6 months post extraction alveolar ridge dimensional changes were evaluated on all sites: an acrylic stent was prepared for each patient and measurements from the alveolar bone to the stent were taken using a periodontal probe PCP UNC 15 (Hu-Friedy). Histological analyses on newly formed bone were performed on one specimen from augmented sites after 3 and 6 months post extraction. Results Untreated alveolar socket showed a stronger volumetric reduction compared to grafted socket. At histological evaluation the slow remodeling process of the graft material was confirmed. At 3 months, bone density was 2.77%, residual Bio-Oss Collagen amounted to 43.75%, and connective tissue was 53.48%. At 6 months, the harvested cylinder was comprised of 44.42% new bone, 12.50% grafted Bio-Oss Collagen and 43.08% connective tissue/ bone marrow. Conclusions The slow remodeling process of graft material seems to contrast the fast remodeling of the blood clot and the alveolar bone resorption, thus compensating the alveolar ridge contraction.

Osteonecrosis of the jaws (ONJ) is a rare but severe complication of antiresorptive medications, such as bisphosphonates, used in the treatment of bone malignancy or osteoporosis. Tooth extraction and dental disease have been strongly associated with ONJ development. Here, we investigated molecular and cellular markers of socket healing after extraction of healthy or teeth with experimental periodontitis (EP) in Wistar-Han rats treated with zoledronic acid (ZA). We included 4 experimental groups: vehicle-treated animals with extraction of healthy teeth or teeth with ligature-induced EP and ZA-treated animals with extraction of healthy teeth or teeth with EP. Animals were pretreated with vehicle or ZA for a week, and EP was induced. Four weeks later, the second maxillary molars were extracted; sockets were allowed to heal for 4 wk; animals were euthanized; and maxillae were isolated. Radiographically, extraction sockets in groups 1, 2, and 3 demonstrated normal healing. Contrary incomplete socket healing was noted after extraction of teeth with EP in ZA-treated rats of group 4. Histologically, persistent inflammation and extensive osteonecrosis were seen in group 4. Disorganization of the collagen network, collagen type III predominance, and lack of collagen fiber insertion in the necrotic bone were associated with impaired socket healing. Cells positive for MMP-9, MMP-13, and α-SMA expression were present at the areas of epithelial invagination and adjacent to osteonecrotic bone. Importantly, human biopsies from patients with ONJ showed similar findings. Our data emphasize the importance of dental disease and tooth extraction in ONJ pathogenesis and help delineate an altered profile in wound-healing markers during ONJ development.

INTRODUCTION: The aim of the study was to observe the relationship between alveolar ridge resorption in mandible and masticatory performance based on gender in complete denture wearers. MATERIALS AND METHODS: The subjects included were those wearing complete denture between the ages of 45-69 years-old, treated at the Dental and Oral Hospital of University Sumatera Utara. Alveolar ridge resorption in mandible was analysed using the panoramic radiograph and masticatory performance was evaluated clinically using the colour-changeable chewing gum. RESULT: 40 patients were included in this study. 50% were women in which 15 women (37.5%) had mild alveolar ridge resorption whilst 5 (12.5%) had severe alveolar ridge resorption. For masticatory performance, 14 women (35%) had good masticatory performance and 6 (15%) had poor masticatory performance. For the men; 17 (42.5%) had mild alveolar ridge resorption whilst 3 (7.5%) had severe alveolar ridge resorption. For masticatory performance, 16 men (40%) had a good masticatory performance and 4 (10%) had a poor masticatory performance. There was a significant correlation between alveolar ridge resorption in mandible and masticatory performance amongst women (p=0.014). However, there was no significant correlation found between gender and alveolar ridge resorption in mandible (p=0.695), between gender and masticatory performance (p=0.716), and between alveolar ridge resorption in mandible and masticatory performance amongst men (p=0.088). CONCLUSION: The alveolar ridge resorption in mandible is associated with masticatory performance amongst women.