Open-Healing Socket Preservation with a Novel Dense Polytetrafluoroethylene (dPTFE) Membrane: A Retrospective Clinical Study.

Background and objectives: Non-resorbable dense polytetrafluoroethylene (dPTFE) membranes are widely used for regeneration procedures, alone or in combination with particulate materials. The aim of this work was to examine the efficacy of a newly developed dPTFE membrane in the management of extraction socket healing. Materials and Methods: The extraction premolar sockets of 44 patients (20 men and 24 women) were preserved. One group received prosthetic rehabilitation with a fixed partial denture (FPD) (PROS group, N = 19) and a second group received immediate implant placement (IMPL group, N = 25). The PROS group sockets were augmented with a bovine derived xenograft and covered with a newly developed dPTFE membrane prior to FPD rehabilitation. Results: In the IMPL group, socket preservation was combined with immediate implant placement. Before (T0) and 6 months after surgery (T1), horizontal and vertical dimensions were measured with customized stents. No significant differences in alveolar bone loss from T0 to T1 were observed between the PROS and IMPL groups in the horizontal dimension for any tooth type. There was a significant difference in alveolar bone loss from T0 to T1 between the two groups for only single-rooted maxillary premolars in the vertical dimension. Conclusions: The use of the examined new dPTFE membrane consistently led to the preservation of hard tissue in the extraction sites.

Delayed Socket Healing After Dental Extraction in Patients Undergoing Myelosuppressive Chemotherapy for Hematological Malignancy: Incidence and Risk Factors.

PURPOSE: The purpose of this study was to measure the frequency and identify factors associated with delayed socket healing after dental extraction in patients undergoing myelosuppressive chemotherapy for hematologic malignancy. MATERIALS AND METHODS: This prospective cohort study focused on delayed healing after extraction in patients with hematologic malignancy. Sockets with delayed healing were defined as those with intense pain and bone exposure 1 week postoperatively. Patients with and without delayed socket healing were compared using the Fisher exact test and Mann-Whitney U test with some variables. Receiver operating characteristics curve analysis was conducted to define cutoff values for delayed healing. RESULTS: One hundred ninety-four dental extractions in 93 patients (median age, 64 yr; range, 20 to 85 yr) were analyzed. The incidence of delayed socket healing was 7.5% (7 of 93 patients). There was no postoperative bleeding. Older age, type of hematologic malignancy (acute leukemia), shorter time from dental extraction to initiation of chemotherapy, low platelet count or hemoglobin level, requirement for red blood cell concentrate or platelet transfusion, and use of an absorbable hemostatic agent were statistically associated with the occurrence of delayed socket healing. Platelet and hemoglobin cutoffs were 4.6 × 104/µL and 7.7 g/dL, respectively. CONCLUSIONS: Although dental extraction can be safely performed in patients undergoing myelosuppressive chemotherapy for hematologic malignancy, oral surgeons should understand the potential risk for delayed socket healing. When considering dental extraction, patients with hematologic malignancy and low hemoglobin or platelet levels should be informed about the possibility of delayed socket healing.

Healing of Postextraction Sockets Preserved With Autologous Platelet Concentrates. A Systematic Review and Meta-Analysis.

PURPOSE: The true benefit of autologous platelet concentrates (APCs) for enhancing the healing of postextraction sites is still a matter of debate, and in recent years several clinical trials have addressed this issue. The purpose of this study was to determine the effectiveness of an APC adjunct in the preservation of fresh extraction sockets. MATERIALS AND METHODS: An electronic search was performed on Medline, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Only controlled clinical trials or randomized clinical trials were included. Selected articles underwent risk-of-bias assessment. The outcomes were complications and adverse events, discomfort and quality of life, bone healing and remodeling assessed by histologic and radiographic techniques, and soft tissue healing. RESULTS: Thirty-three comparative studies were included. Nine articles had a parallel design and 24 had a split-mouth design. Twenty studies were considered to have a low risk of bias and 13 were considered to have a high risk. Overall, 1,193 teeth were extracted from 911 patients. Meta-analysis showed that soft tissue healing, probing depth at 3 months, and bone density at 1, 3, and 6 months were statistically better for the APC group. Qualitative analysis suggested that APCs might be associated with a decrease in swelling and trismus. However, no relevant difference among groups was found for probing depth at 1 month, incidence of alveolar osteitis, acute inflammation or infection, percentage of new bone, and indirect measurement of bone metabolism. CONCLUSION: APCs should be used in postextraction sites to improve clinical and radiographic outcomes such as bone density and soft tissue healing and postoperative symptoms. The actual benefit of APCs on decreasing pain in extraction sockets is still not quantifiable.

The non-healing extraction socket: a diagnostic dilemma - case report and discussion.

STATEMENT OF THE PROBLEM: Delayed healing, or failure of the alveolus to heal post exodontia, is not an uncommon finding in both primary care and hospital practice. Local factors dominate and the majority of cases are the result of clot dissolution, secondary infection, foreign bodies, etc. However, potentially life-threatening, malignant lesions complicating healing can be overlooked and underestimated due to their rare occurrence. PURPOSE OF THE REVIEW: This article presents a contemporary review of the normal physiological process that directs healing within the extraction socket and a differential diagnosis for delayed healing or failure of healing following extraction, with guidance on appropriate management. METHOD: A case report of a squamous cell carcinoma presenting in the clinical setting of a non-healing extraction socket, and a discussion of local and systemic factors that may interfere with healing, are presented. CONCLUSION: The aetiologies of delayed healing and failure of the extraction site to heal are diverse, and the process can be affected by local and systemic factors alike.'Given that neoplastic lesions are relatively rare, it is therefore all the more important for GDPs to remain cognisant of the diagnostic red flags that may raise suspicions of a mitotic lesion to ensure that appropriate referral pathways are instituted.

Immediate effects of tooth extraction on ridge integrity and dimensions.

OBJECTIVES: This study aims to assess possible immediate post-extraction changes in ridge integrity and width. METHODS: Tooth extractions (53 teeth in 30 adults) were performed following atraumatic techniques. Root trunk and ridge width were measured at the crest level in buccolingual direction. Similarly, socket width and buccal plate thickness were also determined. Pre- and post-extraction buccal plate dehiscence, fenestration, or fracture was recorded. Diameter and length of extracted tooth root were also measured. Multinomial logistic regression was used to reveal relationships between ridge outcome (expanded, stable, or collapsed groups) and assessed tooth/site parameters. RESULTS: Post-extraction, buccal plate fracture developed in 5 (9%), dehiscence in 15 (28%), and complete buccal plate loss in 2 sites (4%). Following extraction, ridge width was expanded in 30 (57%), collapsed in 12 (23%), and remained unchanged in 11 (21%) sites. In most sites (72%), post-extraction socket size was wider than pre-extraction root trunk width (p < 0.0001). Socket size was a statistically significant predictor for ridge outcome (expansion or collapse compared to stable) (p < 0.01). CONCLUSION: Loss of ridge integrity is uncommon, while ridge width expansion is a common finding immediately following tooth extraction. The significance of such expansion compared to integrity of socket walls remains to be established. CLINICAL RELEVANCE: Tooth extraction approaches that preserve ridge integrity are accompanied by mainly ridge expansion in ridge width. The significance of such immediate changes for the long-term ridge outcomes (i.e., effect on bone remodeling especially in relation to buccal bone integrity) needs further investigation.

Extraction sockets: erratic healing impeding factors.

AIM: The aim of this exploratory study was to analyse prevalence of extraction sockets showing erratic healing and evaluate factors potentially impeding healing. METHODS: Erratic healing was defined as extraction sites showing clinical observations of fibrous scar tissue occupying the extraction site rather than bone following 12 or more weeks of healing. Computerized tomography was used to evaluate characteristics and calculate Hounsfield unit scores for sites showing erratic healing. RESULTS: A total of 1226 dental records from Seoul National University Dental Hospital archives including patients subject to extractions prior to implant placement were evaluated. Seventy subjects (5.71%) and 97 sites (4.24%) exhibited erratic extraction socket healing. Maxillary incisor/canine sites showed the lowest (0.47%), whereas mandibular molar sites the highest (5.41%) occurrence. In the multivariable analysis, erratic healing was more likely to occur in subjects <60 years old (OR = 2.23, 95%CI = 1.26-3.94), subjects with hypertension (OR = 2.37, 95%CI = 1.24-4.55), in molar sites (OR = 4.91, 95%CI = 1.41-17.07), and following single tooth extractions (OR = 2.98, 95%CI = 1.36-6.53). Computerized tomography showed the highest incidence of bone loss for the buccal wall (49.3%). CONCLUSION: Erratic extraction socket healing appears a not uncommon sequel and local factors seem to be major contributors to its occurrence.

Evaluation of a dense polytetrafluoroethylene membrane to increase keratinized tissue: a randomized controlled clinical trial.

BACKGROUND: The presence of an adequate zone of keratinized tissue has been associated with implant health. This study evaluated the increasing of the zone of keratinized tissue using dense polytetrafluoroethylene (d-PTFE) membranes over extraction sites, without primary closure. MATERIALS AND METHODS: Fifteen sites received d-PTFE membranes. The control sites received no membranes. All cases were sutured with no attempt to achieve primary closure. Before surgery, initial measurements of buccal and lingual keratinized tissue were taken from the mucogingival line (MGL) to the most coronal gingival margins. Final measurements were taken from the buccal MGL to the lingual MGL, 60 and 90 days after extractions. RESULTS: In the test group, a mean increase in the zone of keratinized tissue of 7.06 ± 2.63 mm and 6.6 ± 2.84 mm was observed in 60 and 90 days, respectively. In the control group, a mean increase of 2.46 ± 1.59 mm and 1.40 ± 1.40 mm was observed in 60 and 90 days, respectively. CONCLUSION: Nonexpanded d-PTFE membranes can predictably be used to increase the zone of keratinized tissue in preparation to implant placement.

Evaluation of optimal taper of immediately loaded wide-diameter implants: a finite element analysis.

This study aimed to evaluate the effects of different tapering angles of an immediately loaded wide-diameter implant on the stress/strain distribution in bone and implant after implant insertion in healed or fresh molar extraction sockets. A total of 10 finite element (FE) implant-bone models, including 8.1-mm diameter implant, superstructure, and mandibular molar segment, were created to investigate the biomechanical behavior of different implant taper angles in immediate and delayed placement conditions. The degrees of implant taper ranged from 2° to 14°, and the contact conditions between the immediately loaded implants and bone were set with frictional coefficients (µ) of 0.3 in the healed models and 0.1 in the extracted models. Vertical and lateral loading forces of 189.5 N were applied in all models. Regardless of the degree of implant tapering, immediate loading of wide-diameter implants placed in molar extraction sockets generated higher stress/strain levels than implants placed in healed sockets. In all models, the von Mises stresses and strains at the implant surfaces, cortical bone, and cancellous bone increased with the increasing taper angle of the implant body, except for the buccal cancellous bone in the healed models. The maximum von Mises strains were highly concentrated on the buccal cortical struts in the extracted models and around the implant neck in the healed models. The maximum von Mises stresses on the implant threads were more concentrated in the non-tapered coronal part of the 11° and 14° tapered implants, particularly in the healed models, while the stresses were more evenly dissipated along the implant threads in other models. Under immediate loading conditions, the present study indicates that minimally tapered implants generate the most favorable stress and strain distribution patterns in extracted and healed molar sites.

Alveolar ridge preservation immediately after tooth extraction.

Ridge preservation procedures immediately after tooth extraction, are commonly used with a view to minimising remodelling and shrinkage of the alveolar ridge, associated with socket healing. These procedures may sometimes be effective, but they cannot completely prevent reduction in dimension of the ridge. Certain biomater als used may actually hamper normal deposition of bone within the healing socket, reducing bone trabeculae that can integrate with the implant surface. However, in extraction sockets in alveolar ridges of low bone density, particles of implanted bone substitute incorporated in the healing bone, may enhance the mechanical support for the implant, provided by normal healed bone of low trabecular density alone. This paper reviews biological rationales and procedures for ridge preservation immediately after extraction and comments on their clinical use.

Comparative radiographic evaluation of alveolar bone healing associated with autologous platelet-rich plasma after impacted mandibular third molar surgery.

PURPOSE: This study radiographically evaluated the performance of autologous platelet-rich plasma (PRP) applied in tooth sockets. PATIENTS AND METHODS: Thirty extractions of bilateral impacted mandibular third molars were performed in 15 volunteers (7 men, 8 women; 18 to 22 years old). After extraction of right and left mandibular third molars, the socket at 1 side received the autologous PRP (PRP group) and the other was filled with blood clot (control group). Millimeter periapical radiographs were obtained 7 days, 1 month, and 2, 3, and 6 months postoperatively. Radiographic bone density was quantified 3 times by the same examiner at different moments using HLImage 97 software, and data were statistically analyzed by Statgraf 7.0 software (analysis of variance and Tukey test). RESULTS: In general, there was significantly faster bone formation in sockets treated with PRP (P < .01). Significant bone formation was observed in the first month (P < .01), second month (P < .05), and third month (P < .01) for the PRP group. No statistical differences were observed on the seventh day and sixth month of investigation, yet there were higher means of radiographic bone density in sockets treated with PRP. In the control group, men exhibited significant bone repair compared with women (P < .05). CONCLUSION: Autologous PRP was found to accelerate alveolar bone regeneration, and men presented better repair after tooth extraction.

A pilot case-control study on the alveolar bone density measurement in risk assessment for bisphosphonate-related osteonecrosis of the jaw.

UNLABELLED: Alveolar bone mineral density (BMD) measured by radiography standardized by aluminum step wedge pasted on the film and digitized by a computer system was significantly higher around osteonecrosis lesions than in control cases in a pilot case-control study. High alveolar bone density appears useful as a local risk factor for bisphosphonate-related osteonecrosis of the jaw (BRONJ). INTRODUCTION: In an attempt to find a reliable test method predicting the occurrence of BRONJ in addition to various risk factors suggested, an increase of alveolar bone density near the necrotic lesions was found by computerized radiogrammetry using dental films pasted with an aluminum step wedge (Bone Right, Dentalgraphic.Com Company, Himeji) in six cases of BRONJ. METHODS: The bone mineral density surrounding the osteonecrosis lesions showed distinctly higher density in BRONJ cases compared with age-matched controls. In one subject on bisphosphonate treatment in whom two extractions were simultaneously carried out, BRONJ occurred only at the location with extremely high alveolar bone density, but not at the other site with normal density. CONCLUSION: This method may be useful in detecting a rise of alveolar BMD frequently occurring near the necrotic lesion in subjects with impending risk for BRONJ.

The relationship of glycemic control to the outcomes of dental extractions.

PURPOSE: The aim of this study was to determine whether glycemic control influences healing after tooth extractions. MATERIALS AND METHODS: We enrolled 115 diabetic patients who required dental extractions in this prospective observer-blinded study. Epithelialization of extraction sites was assessed relative to the patient's history, non-fasting blood glucose levels, and glycosylated hemoglobin levels. RESULTS: Of 115 patients, 78 had 1- and 2-week follow-up data. There was no statistically significant difference in the rate of postextraction epithelialization between diabetic patients based on preoperative blood glucose levels, hemoglobin A1c levels, or patient history. Only the size of the extraction site at days 0 and 7 was predictive of future epithelialization. CONCLUSIONS: Glycemic control did not influence postextraction healing in diabetic patients. Recommendations for management of the diabetic patient requiring extractions are discussed.

Action of nicotine and ovariectomy on bone regeneration after tooth extraction in rats.

PURPOSE: The purpose of this study was to evaluate the effects of nicotine and ovariectomy on alveolar bone regeneration after exodontias in rats. MATERIALS AND METHODS: For 30 days, sham ovariectomized (OVX)/NaCl, sham OVX/nicotine, OVX/NaCl, and OVX/nicotine animals were given 2 daily injections of saline or hemisulfate of nicotine. After this period, exodontic procedures were carried out and treatment continued up to the time of euthanasia on days 7 and 14 when the alveoli were removed for further analyses. RESULTS: The data confirmed that nicotine significantly delays the alveolar regeneration process after dental extraction in rats and showed that the association of nicotine with ovariectomy exacerbates these results. CONCLUSION: These results indicate that nicotine potentiated the effect of estrogen deficiency on bone regeneration induced by ovariectomy.

Bone remodeling around implants placed in fresh extraction sockets.

The aim of the present experimental study was to evaluate the physiologic bone remodeling in beagle dogs following the placement of small-diameter (3.25 mm) implants in fresh extraction sites. Five 1-year-old beagle dogs that weighed approximately 10 to 13 kg each were used in this study. The third and fourth premolars (P3, P4) were used as experimental teeth, which were hemisected using a fissure bur; the distal roots were removed carefully using forceps. Implants (3.25-mm wide, 10- or 11.5-mm long) were placed in the fresh extraction sockets with the neck of the implant at the level of the buccal bone crest. The dogs were subsequently put to sleep according to the following schedule: one dog 15 days after implant placement, two dogs after 1 month, and the remaining two dogs after 3 months. The distance from the implant shoulder to the bone wall crest was measured at both the buccal and lingual sites. The width of the buccolingual bone crest was measured using a caliper. Assessments were made immediately after root extraction and at 2, 4, and 12 weeks after implant placement. The mean width of the buccolingual bone crest was 4.5 ± 0.5 mm at the time of root extraction. Subsequently, at 2, 4, and 12 weeks after implant placement, the buccolingual bone width was 4.1 ± 0.5 mm, 3.7 ± 0.3 mm, and 3.5 ± 0.7 mm, respectively. Two weeks after implant placement, the lingual bone crest was measured at 0.2 ± 0.3 mm from the implant shoulder, while the buccal bone crest was 0.3 ± 0.3 mm. After 4 weeks of healing, the mean distance from the implant shoulder to the lingual bone crest was 0.1 ± 0.9 mm, compared to 0.4 ± 0.9 mm for the buccal bone crest. After 12 weeks of healing, the bone crest at the lingual sites was -0.3 ± 0.5 mm from the implant shoulder, compared to 0.8 ± 0.3 mm at the buccal sites. The findings from this study show that although vertical bone remodeling was indeed observed, the mean vertical buccal bone resorption was 0.5 mm. It might be suggested, therefore, that the implant position along the lingual wall and the use of implants with a narrow diameter in relation to the extraction socket width play a key role in reducing the rate of vertical bone resorption at the buccal aspect of implants placed in fresh extraction sockets.

Magnesium-enriched hydroxyapatite compared to calcium sulfate in the healing of human extraction sockets: radiographic and histomorphometric evaluation at 3 months.

BACKGROUND: Reduction of alveolar height and width after tooth extraction may present problems for implant placement, especially in the anterior maxilla where bone volume is important for biologic and esthetic reasons. Different graft materials have been proposed to minimize the reduction in ridge volume. The aim of this study was to compare radiographic and histomorphometric results of magnesium-enriched hydroxyapatite (MHA) and calcium sulfate (CS) grafts in fresh sockets after tooth extractions. METHODS: Forty-five fresh extraction sockets with three bone walls were selected in 15 patients. A split-mouth design was used: 15 sockets on the right side of the jaw received MHA, 15 sockets on the left side received CS, and 15 random unfilled sockets were considered the control (C) group. Intraoral digital radiographs were taken at baseline and at 3 months after graft material placement. At 3 months, cylinder bone samples were obtained for histology and histomorphometry analysis. RESULTS: The difference in mean radiographic vertical bone level from baseline to 3 months was -2.48 +/- 0.65 mm in the CS group, -0.48 +/- 0.21 mm in the MHA group, and -3.75 +/- 0.63 mm in the unfilled C group. Statistically significant differences (P <0.05) were found between CS and MHA groups and between MHA and C groups. Histologic examination revealed bone formation in all treated sites; trabecular bone assessment did not differ among apical, mesial, and coronal portions of the specimens. Mean vital bone measurements for CS, MHA, and C groups were 45.0% +/- 6.5%, 40.0% +/- 2.7%, and 32.8% +/- 5.8%, respectively. Statistically significant differences (P <0.05) were found among all groups. Connective tissue percentages averaged 41.5% +/- 6.7% for the CS group, 41.3% +/- 1.3% for the MHA group, and 64.6% +/- 6.8% for the C group. Statistically significant differences (P <0.05) were found between CS and C groups and between MHA and C groups. The CS-grafted sockets showed 13.9% +/- 3.4% residual implant material, whereas the MHA-treated sockets showed 20.2% +/- 3.2% residual material. The difference between the groups was statistically significant (P <0.05). CONCLUSIONS: Radiographs revealed a greater reduction of alveolar ridge in the CS group than in the MHA group. Histologic examination showed more bone formation and faster resorption in the CS group and more residual implant material in the MHA group.

Immediate occlusal loading of immediately placed implants supporting fixed restorations in completely edentulous arches: a 1-year prospective pilot study.

BACKGROUND: The aims of this pilot study were to evaluate the efficacy of treatment consisting of the immediate loading of implants placed immediately after tooth extraction in full-arch restorations and to compare the clinical and radiographic outcomes of implants placed in healed versus postextraction sites in the same group of patients. METHODS: Twenty-three patients who needed full-arch restorations were treated. One hundred forty-four implants were placed: 59 after tooth extraction (test group) and 85 in healed sites (control group). Within 48 to 72 hours of implant placement, nine maxillary and 15 mandibular arches received screw-retained fixed prostheses, consisting of a titanium framework fabricated with a computer-aided design and manufacturing techniques and composite resin teeth. The insertion torque for implants was >or=30 Ncm. Implant stability measurements (ISQ) and radiographs of the marginal bone level (MBL) change were performed at prosthesis delivery and after 1 year. RESULTS: One implant in the test group and one implant in the control group failed, giving a cumulative success rate of 98.6%; the prosthesis survival rate was 100%. At the 1-year follow-up, no statistically significant difference was found between the control and test sites with respect to MBL change (0.47 +/- 0.18 mm versus 0.57 +/- 0.27 mm) or mean ISQ values (62.24 +/- 1.92 versus 61.34 +/- 2.15). CONCLUSION: These preliminary data suggest that immediate loading of implants placed immediately after extraction may be a viable treatment option for edentulous arches when implants are stable at insertion and are rigidly splinted with screw-retained titanium-resin prostheses.

Healing of extraction sockets in collagenase-2 (matrix metalloproteinase-8)-deficient mice.

Matrix metalloproteinase-8 (MMP-8) participates in skin wound healing and inflammation. We hypothesized that MMP-8 plays a role in wound healing after tooth extraction and in periapical inflammation. Bone formation, collagen metabolism, and inflammation in tooth extraction socket and in periapical lesions were analyzed in wild-type mice and in MMP-8-deficient (MMP-8(-/-)) mice. New trabecular bone area in the extraction sockets and in periapical lesions were similar in both groups. In extraction sockets significantly more type III procollagen was synthesized, and the neutrophil and MMP-9 levels were lower in MMP-8(-/-) mice. The amount of Fas ligand, identified as a substrate for MMP-8, was lower in alveolar mucosa but higher in alveolar bone of MMP-8(-/-) mice. These results indicate that MMP-8 can modulate inflammation and collagen metabolism of alveolar bone and mucosa.

Elastic modulus of posts and the risk of root fracture.

The definition of an optimal elastic modulus for a post is controversial. This work hypothesized that the influence of the posts' elastic modulus on dentin stress concentration is dependent on the load direction. The objective was to evaluate, using finite element analysis, the maximum principal stress (sigma(max)) on the root, using posts with different elastic modulus submitted to different loading directions. Nine 3D models were built, representing the dentin root, gutta-percha, a conical post and the cortical bone. The softwares used were: MSC.PATRAN2005r2 (preprocessing) and MSC.Marc2005r2 (processing). Load of 100 N was applied, varying the directions (0 degrees, 45 degrees and 90 degrees) in relation to the post's long axis. The magnitude and direction of the sigma(max) were recorded. At the 45 degrees and 90 degrees loading, the highest values of sigma(max) were recorded for the lowest modulus posts, on the cervical region, with a direction that suggests debonding of the post. For the 0 degrees loading, the highest values of sigma(max) were recorded for higher modulus posts, on the apical region, and the circumferential direction suggests vertical root fracture. The hypothesis was accepted: the effect of the elastic modulus on the magnitude and direction of the sigma(max) generated on the root was dependent on the loading direction.

Paget's disease of bone and osteonecrosis.

UNLABELLED: Paget's disease of bone, although common in the long bones and pelvis, is less common in the head and neck. A 20-year follow-up is reported of a patient who was diagnosed with Paget's disease following the investigation of her initial oral complaint. Following surgical extraction of two teeth in her maxilla, the sockets have failed to heal, despite numerous attempted interventions. This case highlights both the cranio-maxillofacial and oral manifestations of Paget's disease of bone, its effects on surgical exodontia and the possible effects of bisphosphonate therapy. CLINICAL RELEVANCE: Paget's disease of bone does not manifest in the head and neck commonly but, when it does, there are significant implications for the dentist. Prevention and conservation of the patient's remaining teeth are paramount as the complications of extraction are significant.

Low-Intensity Pulsed Ultrasound Prevents Development of Bisphosphonate-Related Osteonecrosis of the Jaw-Like Pathophysiology in a Rat Model.

We developed a rat model of bisphosphonate-related osteonecrosis of the jaw (BRONJ) by removing a maxillary molar tooth (M1) from ovariectomized rats after treatment with alendronate. To mimic periodontitis, some of the rats were administered Porphyromonas gingivalis (p. gingivalis) at the M1 site every 2 to 3 d for 2 wk. Rats pretreated with alendronate plus p. gingivalis showed delayed healing of socket epithelia, periosteal reaction of alveolar bone formation and lower bone mineral density in the alveolus above adjacent M2 teeth. These abnormalities were prevented by tooth socket exposure to 20 min/d low-intensity pulsed ultrasound (LIPUS), which restored diminished expression of RANKL, Bcl-2, IL-6, Hsp70, NF-κB and TNF-α messenger ribonucleic acids in remote bone marrow, suggesting LIPUS prevented development of BRONJ-like pathophysiology in rat by inducing systemic responses for regeneration, in addition to accelerating local healing. Non-invasive treatment by LIPUS, as well as low-level laser therapy, may be useful for medication-related osteonecrosis of the jaw patients.