Bisphosphonates—What the Dentist Needs to Know: Practical Considerations

Prevalence of dental alterations in patients under bisphosphonates therapy: a systematic review

This systematic review aimed to estimate the prevalence and describe dentoalveolar lesions associated with bisphosphonates therapy. A systematic review of the literature was conducted using the following databases: PubMed, Embase, Cochrane, CINAHL, Scopus, Web of Science, Lilacs, SciElo, and Grey Literature. Quality of individual studies analysis was performed by using Newcastle-Ottawa Scale. Certainty of cumulative evidence was achieved by applying Grading of Recommendations Assessment, Development, and Evaluation (GRADE) criteria. The software R Statistics version 4.0.5 (The R Foundation) was used for proportion estimations per study and corresponding confidence intervals were estimated through the Clopper-Pearson method. Four articles were included for the qualitative synthesis. Two studies were considered of good quality, one of fair, and one of poor quality. A total of 231 patients were encompassed. Widening of the periodontal ligament space (22.2-39.7%), periradicular radiolucencies (20-22.9%), and pulp calcifications (33.3-69.2%) were the most frequent alterations. Certainty of evidence was rated as very low. Based on limited evidence, this systematic review reports a variety of dentoalveolar alterations in patients under bisphosphonate therapy. These features might impact on dental clinical practice. However, the level of evidence is considered very low due to important limitations.

Root canal treatment of compromised teeth as alternative treatment for patients receiving bisphosphonates: 60-month results of a prospective clinical study

AIM

This 60-month prospective study aimed to evaluate tooth survival and healing rates after root canal treatment in patients taking bisphosphonates (BPs). Secondary outcomes were complications and clinical variables observed during and after treatment.

METHODS

Root canal treatment was performed using manual K-file canal instrumentation and a carrier-based filling technique with an epoxy resin-based sealer. Teeth without adequate root/crown integrity were restored by trained operators at the tissue level (TL group) to prevent occlusal/mechanical stress and to enable periapical lesion healing without the risk of root fracture. Other teeth were restored with normal occlusal contacts (OC group). Healthy patients who had undergone one or more root canal treatments of the same type constituted the control group. The relationships of the following variables to survival and health status were examined (chi-squared test and multivariate analysis, P = 0.05): age, gender, smoking habit, tooth location, treatment type, BPs treatment, BPs exposure, initial periapical index (PAI) and occlusal restoration. Survival curves were constructed using Kaplan-Meier analysis, with extraction serving as the end-point.

RESULTS

In total, 65 patients with 109 root canal-treated teeth who were taking BPs were included. At 60 months, data from 57 patients (52F, 5M; median age 65.7 ± 8.6 years) who had undergone 96 root canal treatments were analysed (drop-out rate = 16.9%). The survival rate was 85%, and the success rate was 76%. The control group consisted of 46 patients (21F, 25M; median age 60.3 ± 7.2 years) who had undergone 102 root canal treatments. The survival rate was 88%, with 12 teeth lost during follow-up. The success rate was 73%. In the BP group, 55 teeth were restored normally (OC group) and 41 teeth were restored at the tissue level (TL group). No difference in the success or survival rate was observed between the BP and control groups (P > 0.05). Univariate Kaplan-Meier analysis revealed that only tooth type significantly affected survival status in the BP group. The analysis revealed the clinical relevance of smoking, tooth location and initial PAI on patients' health status (P < 0.05).

CONCLUSION

Root canal treatments and post-endodontic restoration with tissue-level filling procedures represent a safe approach for severely damaged teeth in patients receiving BPs having comparable results to root filled teeth restored with occlusal contacts and to the control group.

Bisphosphonate-related osteonecrosis. Application of adipose-derived stem cells in an experimental murine model

Background

Bisphosphonate-related osteonecrosis of the jaw is a pathological condition without effective established treatment and preventive strategies. The aim of this study was to analyse the effect of adipose-derived stem cells (ASC) in an experimental murine model of osteonecrosis.

Material and Methods

38 Wistar rats were injected intraperitoneally with zoledronic acid. After treatment, upper jaw molars were extracted. The animals were randomly assigned to one of two groups. In the control group, saline solution was applied over the alveolar sockets after the tooth extractions. In the treatment group, ASCs were applied instead of saline solution. The control and treatment groups were subdivided based on the time of euthanasia. A clinical and histological analysis was performed.

Results

The presence of osteonecrosis in alveolar bone was observed in a similar distribution in both groups. In the ASC-treated group, new bone formation was greater than in controls.

Conclusions

In this study, application of ASCs showed greater new bone formation in an osteonecrosis-like murine model. Previous inhibited post-extraction bone remodelling could be reactivated, and these findings appeared to be secondary to implantation of ASCs.

Key words:Osteonecrosis; bisphosphonates, Mesenchymal stem cells (MSC), adipose-derived stem cells (ASCs), zoledronic acid.

Nasolabial Flap Improves Healing in Medication-Related Osteonecrosis of the Jaw

PURPOSE

Medication-related osteonecrosis of the jaw (MRONJ) is an adverse side effect of antiresorptive and antiangiogenic therapeutic agents that is difficult to treat owing to its high relapse rate. The aim of the present study was to determine whether patients with MRONJ treated using decortication and a nasolabial flap compared with those who underwent decortication with mucoperiosteal flaps have better outcomes regarding stable wound closure.

MATERIALS AND METHODS

Two groups of patients with MRONJ and intraoral exposed bone were evaluated in a cohort clinical study retrospectively. The primary predictor variable was the treatment group. The experimental group used the nasolabial flap for wound closure, and the control group used the mucoperiosteal flap for closure. The outcome variable was successful wound closure defined as a symptomless and closed wound after at least 12 months. Other study variables included factors such as perioperative drug holiday, duration of postoperative oral antibiotic administration, and postoperative use of nasogastric feeding tubes. Cox proportional hazard regression analysis and Kaplan-Meier curves were used to determine the factors independently associated with the dependent variable. The Mann-Whitney U test and χ² test were used for analyses regarding group-related data.

RESULTS

Both groups showed similar demographics. The 16 study patients receiving nasolabial flaps had a mean age of 69.9 years, and the 16 control patients receiving mucoperiosteal flaps had a mean age of 71.8 years. Both groups included 10 women and 6 men. Of the 16 patients in each group, 15 had received a bisphosphonate and 1, monoclonal antibody therapy. All evaluated patients underwent combined treatment, including decortication and intravenous antibiotics. Of the 16 patients receiving nasolabial flaps, symptomless intact wound closure was achieved in 68.8%. Of the 16 patients with mucoperiosteal closure, 18.7% achieved wound closure, with 81.2% developing a relapse of MRONJ, a statistically significant difference (P < .001). No statistically significant differences were found between the 2 groups in the demographic variables. The mean interval to relapse for the experimental and control groups was 13.6 ± 7.8 and 8.2 ± 7.9 months, respectively (P = .017).

CONCLUSIONS

MRONJ is a complication of antiosteoclastic treatment of mostly oncologic, palliative patients, which requires a very methodical approach to surgical treatment. A variety of different methods have been reported. The use of nasolabial flaps can be considered as a highly reliable option for coverage the bone wound with less morbidity than microvascular free flaps and better long-term results compared with mucoperiosteal flaps.

Prevention and management of osteonecrosis of the jaw secondary to bone-targeted therapy in patients with kidney cancer

PURPOSE OF REVIEW

The aim of this revision is prevention and management of osteonecrosis of the jaw (ONJ) secondary to bone-targeted therapy in patients with kidney cancer.

RECENT FINDINGS

Patients with kidney cancer treated with zoledronate suffered from ONJ earlier compared with patients with breast cancer or multiple myeloma; among men, ONJ occurred at 24 months of zoledronic acid treatment in more than 80% of the patients and much earlier, in respect to patients with prostate cancer or multiple myeloma. Protective factors against an ONJ can be sequential prescription of different bisphosphonates and female sex. Less data are available on ONJ secondary to denosumab administration in patients with kidney cancer.

SUMMARY

Bone metastases, developing in about 30% of the patients with metastatic renal cell carcinoma, are typically osteolytic on imaging and cause significant morbidity and poor quality of life. Incidence of skeletal-related events has been reported to reach 3.38 per year in such patients. To decrease the incidence of ONJ, a maxillofacial examination must be performed in all patients before treatment with bisphosphonates, in particular in patients with metastatic renal cell carcinoma treated with sunitinib alone or in association with zoledronate. The management of ONJ consider a conservative approach.

Alendronate-associated osteonecrosis of the jaws: a review of the main topics

Bisphosphonates is a group of inorganic pyrophosphates analogues that suppress bone resorption by inducing osteoclast inactivation, being frequently used for management of diseases affecting bone metabolism, bone metastases and bone tumors. However, since 2003 many cases describing the presence of necrotic bone exposures in the jaws have been described in patients receiving these drugs, what represent a significant complication of bisphosphonates treatment. The overall incidence of bisphosphonate-related osteonecrosis of the jaws is low, ranging from 0.7% to 12%, mainly observed in those patients receiving intravenously treatment. Osteonecrosis of the jaws associated to oral bisphosphonate, particularly alendronate, has also been reported by a number of authors. Considering that alendronate is one of the most used drugs worldwide, specially for treatment of osteoporosis, a better understanding of osteonecrosis of the jaws related to its use and how to manage these patients is extremely important. Therefore, in the current manuscript the authors aim to review the most important topics related to this pathological presentation.

Key words:Bisphosphonates, alendronate, bisphosphonate-related osteonecrosis of the jaws, osteonecrosis.

Stomatological management of head and neck cancer patients treated with chemotherapy and radiotherapy

Treatment of head and neck cancer with radiotherapy and/or chemotherapy can cause oral damage. Long-term treatment can damage the salivary glands, the oral mucosa, and the maxilla, leading to altered production of saliva and to multiple infections. These lesions can be prevented, limited or avoided by thorough evaluation prior to treatment and by therapeutic follow-up and preventive measures. The dentist must have strong medical knowledge of the possible short-, medium-, and long-term oral complications of the cancer treatment, and must have knowledge of the protocols for oral management of cancer patients. The availability of a multidisciplinary medical team together with a dentist to attend to the patient prior to the cancer treatment, as well as close communication between team members during and after treatment, is crucial. The aim of the present study was review the stomatological management of head and neck cancer patients treated with chemotherapy and radiotherapy and summarizing current treatments, therapeutic innovation and tissue regeneration perspectives.

Metagenomic investigation of microbes and viruses in patients with jaw osteonecrosis associated with bisphosphonate therapy

OBJECTIVE

The goal of this preliminary study was to use metagenomic approaches to investigate the taxonomic diversity of microorganisms in patients with bisphosphonate-related osteonecrosis of the jaw (BRONJ).

STUDY DESIGN

Samples of saliva for planktonic microbial analysis and biofilm cultivation were collected from 10 patients (5 with BRONJ and 5 non-BRONJ control subjects) who met all ascertainment criteria. Prophage induction experiments-16S rRNA polymerase chain reaction and 454 pyrosequencing-and epifluorescent microscopy were performed for characterization and enumeration of microbes and viruses.

RESULTS

Three phyla of microbes-Proteobacteria (70%), Firmicutes (26.9%), and Actinobacteria (1.95%)-dominated all BRONJ samples and accounted for almost 99% of the total data. Viral abundance was ∼1 order of magnitude greater than microbial cell abundance and comprised mainly phage viruses.

CONCLUSIONS

Individuals with jaw osteonecrosis harbored different microbial assemblages than nonaffected patients, and in general viral abundance and prophage induction increased with biofilm formation, suggesting that biofilm formation encouraged lysogenic interactions between viruses and microbial hosts and may contribute to pathogenicity.

What you need to know about bisphosphonates: an overview and general recommendations for orthodontic treatment

The orthodontic treatment of patients on bisphosphonates is becoming an increasing aspect of contemporary practice. This article will draw attention to the chemical structure and effects of these drugs on bone and will provide the latest recommendations to avoid potential sequelae.

Osteonecrosis of the jaw onset times are based on the route of bisphosphonate therapy

PURPOSE

Osteonecrosis of the jaw (ONJ) has been reported to be associated with patients receiving bisphosphonate (BP) therapy. There are many reports that suggest that the time of exposure to BPs is a significant risk factor for ONJ and that the greatest risk occurs after dentoalveolar surgery. The aim of this study was to retrospectively investigate the duration of BP therapy and related events before the onset of ONJ based on an intravenous (IV) or oral route of administration.

MATERIALS AND METHODS

We conducted a retrospective cohort study of patients referred to our institution to identify the onset of ONJ based on the exposure to BP therapy and associated triggers (ie, dentoalveolar surgery or spontaneous occurrence) based on the route of BP administration. Demographic data (ie, age, gender, and race), medical diagnosis related to BP therapy, and information as to whether the BP therapy was continued at the time of ONJ diagnosis were also collected.

RESULTS

We reviewed the records for 114 patients with a history of ONJ. We divided patient cohorts by route of BP administration, with 76 patients having a history of IV BP therapy and 38 patients having a history of oral BP therapy. The overall onset of ONJ was earlier in the IV BP group (median, 3 years) compared with the oral BP group (median, 5 years). There was no statistical difference in the duration to occurrence of ONJ associated with dental extraction compared with spontaneous occurrence for both the IV and oral BP groups.

CONCLUSIONS

The median onset of ONJ for patients undergoing IV BP therapy occurs earlier than the median onset for patients undergoing oral BP therapy, and there was no difference in onset occurring spontaneously and after dental extraction. The significance of these findings suggests that patients who receive IV BP therapy should be closely evaluated after the initiation of BP therapy. The lack of evidence suggesting greater onset after dental extraction may provide clinical support for dentoalveolar surgery that is indicated for patients with a history of BP therapy. Research focusing on the clinical circumstances and physiologic events during early antiresorptive therapy may provide insight as to the critical risk factors.

Laser GaAlAs (λ860 nm) photobiomodulation for the treatment of bisphosphonate-induced osteonecrosis of the jaw

OBJECTIVE

The aim of this article is to report a case of bisphosphonate-induced osteonecrosis (ONJ-BP) of the jaw treated by curettage of the necrotic bone, low-level laser therapy (LLLT), and antibiotic therapy.

BACKGROUND DATA

ONJ-BP is characterized by painful ulcerations of the oral mucosa, is prone to bone necrosis that does not heal within 8 weeks after diagnosis, and is often difficult to treat. No definitive standard of care has been established for ONJ-BP. LLLT improves wound healing, relieves pain, and appears to be a promising treatment modality for patients with ONJ-BP.

MATERIALS AND METHODS

An 82-year-old man taking intravenous bisphosphonate presented with ONJ-BP after tooth extraction. The patient was treated by LLLT using a GaAlAs diode laser with the following settings: wavelength, 860 nm; 70 mW; continuous wave; and spot size 4 mm(2). An energy density of 4.2 J/cm(2) per point was applied in a punctual contact manner every 48 h for 10 days, in association with antibiotic therapy and curettage of the necrotic bone. Reduction in painful symptoms was reported after the second irradiation session, and tissue healing was complete at the end of the third week following oral curettage. The patient was followed up for 12 months and exhibited good oral healt and quality of life.

CONCLUSIONS

The therapeutic protocol used in this study had a positive effect on tissue healing and remission of painful symptoms, resulting in better oral health and quality of life for the patient.

Antibiotic effects on bacterial profile in osteonecrosis of the jaw

OBJECTIVE

Oral infection is considered to play a critical role in the pathogenesis of bisphosphonate-related osteonecrosis of the jaw (BRONJ), and antibiotic therapy has become a mainstay of BRONJ therapy. This study was aimed to investigate the effect of antibiotics on bacterial diversity in BRONJ tissues.

MATERIALS AND METHODS

The bacterial profile from soft tissues associated with the BRONJ lesion was determined using 16S rRNA-based denaturing gradient gel electrophoresis (DGGE) and sequencing. Twenty BRONJ subjects classified as stage 0-2 were enrolled in this study, and patient groups were divided into an antibiotic cohort (n=10) treated with systemic antibiotic and a non-antibiotic cohort (n=10) with no prior antibiotic therapy.

RESULTS

The DGGE fingerprints indicated no significant differences in bacterial diversity of BRONJ tissue samples. Patients on antibiotics had higher relative abundance of phylum Firmicutes with bacterial species, Streptococcus intermedius, Lactobacillus gasseri, Mogibacterium timidum, and Solobacterium moorei, whereas patients without antibiotics had greater amounts of Parvimonas micra and Streptococcus anginosus. Thirty percent of bacterial populations were uncultured (yet-to be cultured) phylotypes.

CONCLUSION

This study using limited sample size indicated that oral antibiotic therapy may have a limited efficacy on the bacterial population associated with BRONJ lesions.

Bisphosphonate-related osteonecrosis of the jaw: position paper from the Allied Task Force Committee of Japanese Society for Bone and Mineral Research, Japan Osteoporosis Society, Japanese Society of Periodontology, Japanese Society for Oral and Maxillofacial Radiology, and Japanese Society of Oral and Maxillofacial Surgeons

Bisphosphonates (BPs) have been widely, efficiently, and safely used for the treatment of osteoporosis, malignant hypercalcemia, bone metastasis of solid cancers, and multiple myeloma bone diseases. Accumulating recent reports describe that surgical dental treatments in patients with cancer or osteoporosis who have been receiving intravenous or oral BPs are associated with osteonecrosis of the jaw (bisphosphonate-related osteonecrosis of the jaw, BRONJ). The accurate incidence, clinical backgrounds, and pathogenesis of BRONJ have been unclear and appropriate approaches for prevention and treatment have not been established to date. To address the current situation of BRONJ in Japan, the "Allied Task Force Committee of Bisphosphonate-Related Osteonecrosis of the Jaw," consisting of physicians specializing in bone biology, orthopedic surgery, rheumatology, obstetrics/gynecology, and medical oncology and dentists specializing in oral surgery, periodontology, dental radiology, and oral pathology, was organized. The committee attempted to propose a standard position paper for the treatment of BRONJ. The committee expects that this proposal will provide objective and correct scientific information on BRONJ and will serve as a reference for conducting dental procedures for patients receiving BPs and in designing prevention and treatment of BRONJ. However, because this position paper is not based on direct clinical evidence, it should be used as a reference, and a decision on treatment in each case should be made after an extensive discussion among physicians, dentists/oral surgeons, and the patients.

Nanotechnological approaches against Chagas disease

Over several thousand years, the flagellated Trypanosome cruzi-causative agent of Chagas disease-developed a complex life cycle between the reduviidae vectors and its human hosts. Due to their silent and hidden location, the intracellular amastigotes are mainly responsible for the nearly 50,000 annual deaths caused by the chronic chagasic cardiomyopathy. Chagas disease is the most important parasitic disease in the Americas, though treatments have not evolved towards a more efficient pharmacotherapy that (i) eradicates the scarce amastigotes present at the indeterminate/chronic form and (ii) employs less toxic drugs than benznidazole or nifurtimox. Nano-drug delivery systems (nanoDDS) represent useful means to selectively deliver the drug to intracellular targets. However, preclinical research in Chagas must be extended in order to improve the chances of a clinical implementation. The stages involved in this process are (i) selection of the appropriate drug for a specific parasite, (ii) development of a drug-loaded nanoDDS structure that displays the adequate pharmacokinetics, biodistribution and intracellular transit and (iii) selection of the right parasite form to target and the right stage of the disease for the treatment to be started. In this review we will critically overview the few research works published in the last 20years in the context of nanotechnology and Chagas diseases and highlight the gaps in knowledge towards the design of more efficient medicines to address this endemic.