Important aspects concerning alendronate-related osteonecrosis of the jaws: a literature review

The effects of sodium alendronate on socket healing after tooth extraction: a systematic review of animal studies

The aim of this systematic review was to answer the following question: "Does alendronate, a nitrogen-containing bisphosphonate, improve or impair alveolar socket healing after tooth extraction in animal models"? To this end, a systematic review of the literature was carried out in PubMed, Scopus, LILACS, Web of Science, as well as in the gray literature up to May 2023. Preclinical studies that evaluated alveolar healing after tooth extraction and the intake of sodium alendronate compared with placebo were included. Two investigators were responsible for screening the articles independently, extracting the data, and assessing their quality through the SYRCLE's RoB tool for randomized trials in animal studies. The study selection process, study characteristics, risk of bias in studies, impact of alendronate on bone healing, and certainty of evidence were described in text and table formats. Methodological differences among the studies were restricted to the synthesis methods. The synthesis of qualitative results followed the Synthesis Without Meta-analysis (SWiM) reporting guideline. From the 19 included studies, five were considered to have low risk, three were of unclear risk, and eleven presented a high risk of bias. The studies were considered heterogeneous regarding alendronate posology, including its dosage and route of administration. Furthermore, a variety of animal species, different age ranges, diverse teeth extracted, and exposure or not to ovariectomy contributed to the lack of parity of the selected studies. Our results indicated that alendronate monotherapy negatively affects the early phase of wound healing after tooth extraction in preclinical studies, suggesting that the bone resorption process after tooth extraction in animals treated with alendronate might impair the bone healing process of the extraction socket. In conclusion, alendronate administration restrains bone resorption, thereby delaying alveolar socket healing . Future studies should be conducted to validate these findings and to better understand the effects of alendronate therapy on oral tissues.

Early protection against bone stress injuries by mobilization of endogenous targeted bone remodeling

Bone stress injuries are common overuse injuries, especially in soldiers, athletes, and performers. In contrast to various post-injury treatments, early protection against bone stress injuries can provide greater benefit. This study explored the early protection strategies against bone stress injuries by mobilization of endogenous targeted bone remodeling. The effects of various pharmaceutical/biophysical approaches, individual or combinational, were investigated by giving intervention before fatigue loading. We optimized the dosage and administration parameters and found that early intervention with pulsed electromagnetic field and parathyroid hormone (i.e., PEMF+PTH) resulted in the most pronounced protective effects among all the approaches against the bone stress injuries. In addition, the mechanisms by which the strategy mobilizes targeted bone remodeling and enhances the self-repair capacity of bone were systematically investigated. This study proposes strategies to reduce the incidence of bone stress injuries in high-risk populations (e.g., soldiers and athletes), particularly for those before sudden increased physical training.

A Review Into the Effects of Pamidronic Acid and Zoledronic Acid on the Oral Mucosa in Medication-Related Osteonecrosis of the Jaw

Medication-related osteonecrosis of the jaw (MRONJ) is a growing problem without an effective treatment, presenting as necrotic bone sections exposed via lesions in the overlying soft tissue. There is currently a lack of clarity on how the factors involved in MRONJ development and progression contribute to disease prognosis and outcomes. Bisphosphonates (BPs), the most common cause of MRONJ, affect bone remodeling, angiogenesis, infection, inflammation and soft tissue toxicity, all of which contribute to MRONJ development. This article reviews the cellular mechanisms through which BPs contribute to MRONJ pathology, with a focus on the effects on cells of the oral mucosa. BPs have been shown to reduce cell viability, reduce proliferation, and increase apoptosis in oral keratinocytes and fibroblasts. BPs have also been demonstrated to reduce epithelial thickness and prevent epithelial formation in three-dimensional tissue engineered models of the oral mucosa. This combination of factors demonstrates how BPs lead to the reduced wound healing seen in MRONJ and begins to uncover the mechanisms through which these effects occur. The evidence presented here supports identification of targets which can be used to develop novel treatment strategies to promote soft tissue wound healing and restore mucosal coverage of exposed bone in MRONJ.

Preventative effects of metformin on glucocorticoid-induced osteoporosis in rats

This study evaluated the preventative effects of metformin (Met) on glucocorticoid (GC)-induced osteoporosis in a rat model, compared with alendronate (Aln). Twenty-eight 3-month-old female Sprague-Dawley rats were randomly assigned into four groups: normal control (Ctr), methylprednisolone (MP, 13 mg/kg/day, sc, 5 days per week), MP plus Aln orally (1 mg/kg/day), and MP plus Met orally (200 mg/kg/day). After 9 weeks, serum bone metabolic biochemistry, bone densitometry and histomorphometry were performed. The GC-induced osteoporosis model was characterized by decreased osteocalcin, increased tartrate-resistant acid phosphatase-5b (TRAP-5b), and decreased bone mineral density (BMD) in the femur and fifth lumbar vertebra (L5). Histomorphometrically, MP significantly decreased trabecular bone volume, decreased bone formation and increased bone resorption in proximal metaphysis, compared with the controls. Aln and Met increased the BMDs of femur (0.305 ± 0.011 vs. 0.280 ± 0.012, P < 0.05; 0.304 ± 0.019 vs. 0.280 ± 0.012, P < 0.05) and L5 (0.399 ± 0.029 vs. 0.358 ± 0.022, P < 0.05; 0.397 ± 0.022 vs. 0.358 ± 0.022, P < 0.05), compared with the model group. Met increased osteocalcin and decreased TRAP-5b, but Aln only decreased TRAP-5b, compared with model group. In histomorphometry of tibial proximal metaphysis, Aln and Met increased trabecular bone volume (39.21 ± 2.46 vs. 30.98 ± 5.83, P < 0.05; 38.97 ± 5.56 vs. 30.98 ± 5.83, P < 0.05), while Met increased the bone formation dynamic parameters and decreased bone resorption dynamic parameters, but Aln just decreased bone resorption dynamic parameters, compared with model group significantly. These findings suggest that metformin prevents GC-induced bone loss by suppressing bone resorption and stimulating bone formation in trabecular bone. The action mode of metformin was different from alendronate, which only suppressed bone resorption.

The effect of ovariectomy and 2 antiresorptive therapeutic agents on bone response in rats: A 3-dimensional imaging analysis

OBJECTIVE

The aim of this study was to evaluate bone mineral density (BMD) and microarchitecture in femurs and maxillary bones of ovariectomized (OVX) rats treated or not treated with alendronate (ALD) or odanacatib (ODN).

STUDY DESIGN

Twenty rats were divided into groups: SHAM, OVX, OVX/ALD, and OVX/ODN. After 12 weeks, the femurs and maxillae were removed and subjected to 3-dimensional analysis by micro-computed tomography. Results were analyzed with 1-way analysis of variance and Tukey's post hoc test (α = 0.05).

RESULTS

OVX decreased maxillary and femoral BMD and altered femoral microarchitecture (P < .05). The drugs increased BMD of both types of bones, but only ALD maintained the phenotype similar to the SHAM group. The action of ALD was limited to the femoral trabecular separation (Tb.Sp). OVX and the drugs had no effect on the microarchitecture of the maxilla (P > .05).

CONCLUSIONS

ALD and ODN therapy increased BMD in both bones after ovariectomy. ALD was more successful than ODN in preserving the morphology of bone similar to the SHAM group. ALD maintained the phenotype for Tb.Sp in the femur, but ODN did not. In the maxillae, neither ovariectomy nor the 2 antiresorptive drugs had significant effects on microarchitecture.

A case of tooth fracture occurred upon medicating bisphosphonate for an elderly person: Preservation therapy and responses for Stage 0 of bisphosphonate-related osteonecrosis of jaw

This case report aimed to report the progress of preservation therapy and response of symptoms and signs for Stage 0 of bisphosphonate-related osteonecrosis of jaw (BRONJ). A 68-year-old female was recognized having a tooth at the left upper first molar fracture upon medicating bisphosphonate (BP) in 2007. At that time, the extraction of the tooth was an absolute contraindication. Therefore, we performed preservation therapy. We observed the symptoms and signs every month. After 5 months, swelling and redness in the entire first molar tooth were seen and fistula formed partly. Bone exposure was not seen. We administrated antibiotics immediately. As a result, symptoms disappeared. On April 10, 2009, the patient visited us as she felt a sense of incongruity in the lower left first and second molar teeth. Clinically, there were no symptoms of pain. However, we observed the radiolucent finding in about 5 mm diameter at apical position by X-ray photography; we considered a possibility of Stage 0 for BRONJ. We immediately administered medicine for 5 days and the symptoms disappeared. At present, no inflammation with signs and symptoms at the upper left first molar and lower left first, second molar parts is shown. We performed preservation therapy for tooth fracture case medicating of BP. Immediate responses for inflammation and symptoms of the Stage 0 of BRONJ have led to success. Hence, dentists should perform regular clinical observation, and enough education to the patient for BRONJ is necessary.

Annual review of selected scientific literature: Report of the committee on scientific investigation of the American Academy of Restorative Dentistry

STATEMENT OF PROBLEM

It is clear the contemporary dentist is confronted with a blizzard of information regarding materials and techniques from journal articles, advertisements, newsletters, the internet, and continuing education events. While some of that information is sound and helpful, much of it is misleading at best.

PURPOSE

This review identifies and discusses the most important scientific findings regarding outcomes of dental treatment to assist the practitioner in making evidence-based choices. This review was conducted to assist the busy dentist in keeping abreast of the latest scientific information regarding the clinical practice of dentistry.

MATERIAL AND METHODS

Each of the authors, who are considered experts in their disciplines, was asked to peruse the scientific literature published in 2015 in their discipline and review the articles for important information that may have an impact on treatment decisions. Comments on experimental methodology, statistical evaluation, and overall validity of the conclusions are included in many of the reviews.

RESULTS

The reviews are not meant to stand alone but are intended to inform the interested reader about what has been discovered in the past year. The readers are then invited to go to the source if they wish more detail.

CONCLUSIONS

Analysis of the scientific literature published in 2015 is divided into 7 sections, dental materials, periodontics, prosthodontics, occlusion and temporomandibular disorders, sleep-disordered breathing, cariology, and implant dentistry.

All-trans retinoic acid shifts rosiglitazone-induced adipogenic differentiation to osteogenic differentiation in mouse embryonic fibroblasts

Rosiglitazone (RSG) is a potent drug used in the treatment of insulin resistance; however, it is associated with marked skeletal toxicity. RSG-induced osteoporosis may contribute to the promotion of adipogenic differentiation at the expense of osteogenic differentiation in bone marrow stromal cells. The aim of this study was to investigate whether RSG-induced bone toxicity can be reversed by combined treatment with all-trans retinoic acid (ATRA). We examined different osteogenic markers in mouse embryonic fibroblasts (MEFs) following treatment with RSG, ATRA, or RSG and ATRA in combination. We examined the effects of RSG and/or ATRA on ectopic bone formation, and dissected the possible molecular mechanisms underlying this process. We found that ATRA or RSG both induced alkaline phosphatase (ALP) activity in the MEFs, and that the ATRA-induced ALP activity was enhanced by RSG and vice versa. However, only the combination of RSG and ATRA increased the expression of osteopontin and osteocalcin, promoted matrix mineralization, and induced ectopic ossification in MEFs. Mechanistically, we found that the osteogenic differentiation induced by the combination of RSG and ATRA may be mediated partly by suppressing RSG-induced adipogenic differentiation and activating bone morphogenetic protein (BMP)/Smad signaling. On the whole, our findings demonstrate that RSG in combination with ATRA promotes the commitment of MEFs to the osteoblast lineage. Thus, the combination of these two agents may prove to be a promising and novel therapeutic regimen for insulin resistance without skeletal toxicity. It may also be a better strategy with which to prevent RSG-induced osteoporosis.

Interleukin-1 receptor-associated kinase-4 (IRAK4) promotes inflammatory osteolysis by activating osteoclasts and inhibiting formation of foreign body giant cells

Formation of foreign body giant cells (FBGCs) occurs following implantation of medical devices such as artificial joints and is implicated in implant failure associated with inflammation or microbial infection. Two major macrophage subpopulations, M1 and M2, play different roles in inflammation and wound healing, respectively. Therefore, M1/M2 polarization is crucial for the development of various inflammation-related diseases. Here, we show that FBGCs do not resorb bone but rather express M2 macrophage-like wound healing and inflammation-terminating molecules in vitro. We also found that FBGC formation was significantly inhibited by inflammatory cytokines or infection mimetics in vitro. Interleukin-1 receptor-associated kinase-4 (IRAK4) deficiency did not alter osteoclast formation in vitro, and IRAK4-deficient mice showed normal bone mineral density in vivo. However, IRAK4-deficient mice were protected from excessive osteoclastogenesis induced by IL-1β in vitro or by LPS, an infection mimetic of Gram-negative bacteria, in vivo. Furthermore, IRAK4 deficiency restored FBGC formation and expression of M2 macrophage markers inhibited by inflammatory cytokines in vitro or by LPS in vivo. Our results demonstrate that osteoclasts and FBGCs are reciprocally regulated and identify IRAK4 as a potential therapeutic target to inhibit stimulated osteoclastogenesis and rescue inhibited FBGC formation under inflammatory and infectious conditions without altering physiological bone resorption.