Osseointegration of dental implants and osteonecrosis of the jaw in patients treated with bisphosphonate therapy: a systematic review

Bisphosphonates and Their Connection to Dental Procedures: Exploring Bisphosphonate-Related Osteonecrosis of the Jaws

Bisphosphonates are widely used to treat osteoporosis and malignant tumors due to their effectiveness in increasing bone density and inhibiting bone resorption. However, their association with bisphosphonate-related osteonecrosis of the jaws (BRONJ) following invasive dental procedures poses a significant challenge. This review explores the functions, mechanisms, and side effects of bisphosphonates, emphasizing their impact on dental procedures. Dental patients receiving bisphosphonate treatment are at higher risk of BRONJ, necessitating dentists' awareness of these risks. Topical bisphosphonate applications enhance dental implant success, by promoting osseointegration and preventing osteoclast apoptosis, and is effective in periodontal treatment. Yet, systemic administration (intravenous or intraoral) significantly increases the risk of BRONJ following dental procedures, particularly in inflamed conditions. Prevention and management of BRONJ involve maintaining oral health, considering alternative treatments, and careful pre-operative and post-operative follow-ups. Future research could focus on finding bisphosphonate alternatives with fewer side effects or developing combinations that reduce BRONJ risk. This review underscores the need for further exploration of bisphosphonates and their implications in dental procedures.

Do Systemic Diseases and Medications Influence Dental Implant Osseointegration and Dental Implant Health? An Umbrella Review

The aim of this umbrella review is to evaluate what are the most common medications and systemic diseases that can affect bone-implant integration, the success rate and survival rate of dental implants, peri-implant tissue health, and implant loss. Systematic reviews, with meta-analysis or not, about how systemic diseases and medications influence dental implant osseointegration, survival rate, success rate, and peri-implant diseases, published only in the English language, are electronically searched across the most important scientific databases. The present umbrella review includes eight systematic reviews, and osteoporosis and diabetes are the most investigated pathologies. Systemic diseases, such as neurologic disorders, HIV, hypothyroidism, cardiovascular diseases, and drugs, such as beta blockers, anti-hypertensives, or diuretics do not show a decreased rate of implant osseointegration. It seems that drugs, such as proton-pump inhibitors (PPIs) or serotonin reuptake inhibitors (SSRIs), negatively affect implant osseointegration. Few studies compare the effects of drugs and systemic diseases on the parameters considered in this overview. It is important to underline how the results of this review need to be validated with subsequent and more reviews.

Impact of bisphosphonate drugs on dental implant healing and peri-implant hard and soft tissues: a systematic review

Objective

Implantology represents the gold standard for oral rehabilitation, unfortunately, often, despite there are no local contraindications to this type of rehabilitation, there are uncertainties regarding the general health of our patients. Many patients nowadays take bisphosphonate drugs, often without first seeking advice from an oral surgeon or a dentist. The purpose of this review is precisely to highlight any contraindications to this type of treatment reported in the literature, in patients who take or have taken bisphosphonate drugs.

Methods

For this study the scientific information sources were consulted using as search terms “(“bisphosphonate AND “dental implant”)”, obtaining 312 results, these were subsequently skimmed according to the inclusion and exclusion criteria, and further evaluated their relevance to the study and the presence of requested outcomes.

Results

Only 9 manuscripts (RCTs, Multicentric studies and Clinical Trials) were included in this review, as they respected the parameters of this review, they were analyzed and it was possible to draw important results from them. Surely from this study it is understood that the use of bisphosphonate drugs does not represent an absolute contraindication to implant therapy, it is evident how adequate pharmacological prophylaxis, and an adequate protocol reduce the risks regarding implant failures. Furthermore, the values of marginal bone loss over time seem, even if not statistically significant, to be better in implant rehabilitation with bisphosphonate drugs association. Only a few molecules like risedronate, or corticosteroids, or some conditions like smoking or diabetes have shown a high risk of surgical failure.

Conclusion

Although this study considered different studies for a total of 378 patients and at least 1687 different dental implants, showing better results in some cases for dental implant therapy in cases of bisphosphonate intake, further clinical, randomized and multicentric studies are needed, with longer follow-ups, to fully clarify this situation which often negatively affects the quality of life of our patients and places clinicians in the face of doubts.

Titanium alkalinization improves response of osteoblasts to zoledronic acid

This investigation is aimed to determine the effect of the modification of titanium surface with NaOH on the metabolism of osteoblasts treated with zoledronic acid (ZA). Machined and NaOH-treated titanium disks were used. Surfaces were characterized by scanning electron microscopy, confocal microscopy, and x-ray photoelectron spectroscopy (XPS) analysis. Human osteoblasts were seeded onto the disks. After 24 h, cells were treated with ZA at 5 μM for 7 days. At this point, cell viability, collagen synthesis, total protein production, alkaline phosphatase activity, and mineral nodule deposition were assessed. The results of surface roughness were descriptively and statistically analyzed (t-Student), while the XPS results were qualitatively described. Cell metabolism data were analyzed by the analysis of variance two-way and Tukey tests at a 5% significance level. The results demonstrated that NaOH-treatment increased surface roughness (p < .05) and confirmed the presence of sodium titanate and a pH switch on the NaOH-treated disks. This modification also resulted in higher cell viability, collagen synthesis, total protein production, and alkaline phosphatase by osteoblasts when compared to cells seeded onto machined disks (p < 0.05). In the presence of ZA, all cellular metabolism and differentiation parameters were significantly reduced for cells seeded on both surfaces (p < 0.05); however, the cells seeded onto modified surfaces showed higher values for these parameters, except for mineral nodule deposition (p < 0.05). NaOH modification improved cell adhesion and metabolism of osteogenic cells even in the presence of ZA. The surface modification of titanium with NaOH solution may be an interesting strategy to improve metabolism and differentiation of osteoblasts and accelerate osseointegration process, mainly for tissues exposed to ZA.

Endosseous Dental Implant Materials and Clinical Outcomes of Different Alloys: A Systematic Review

In recent years, implantology has made significant progress, as it has now become a safe and predictable practice. The development of new geometries, primary and secondary, of new surfaces and alloys, has made this possible. The purpose of this review is to analyze the different alloys present on the market, such as that in zirconia, and evaluate their clinical differences with those most commonly used, such as those in grade IV titanium. The review, conducted on major scientific databases such as Scopus, PubMed, Web of Science and MDPI yielded a startling number of 305 results. After the application of the filters and the evaluation of the results in the review, only 10 Randomized Clinical Trials (RCTs) were included. Multiple outcomes were considered, such as Marginal Bone Level (MBL), Bleeding on Probing (BoP), Survival Rate, Success Rate and parameters related to aesthetic and prosthetic factors. There are currently no statistically significant differences between the use of zirconia implants and titanium implants, neither for fixed prosthetic restorations nor for overdenture restorations. Only the cases reported complain about the rigidity and, therefore, the possibility of fracture of the zirconium. Certainly the continuous improvement in these materials will ensure that they could be used safely while maintaining their high aesthetic performance.

Zoledronic acid inhibits osteoclastogenesis and bone resorptive function by suppressing RANKL‑mediated NF‑κB and JNK and their downstream signalling pathways

Targeting excessive osteoclast differentiation and activity is considered a valid therapeutic approach for osteoporosis. Zoledronic acid (ZOL) plays a pivotal role in regulating bone mineral density. However, the exact molecular mechanisms responsible for the inhibitory effects of ZOL on receptor activator of nuclear factor (NF)-κB ligand (RANKL)-induced osteoclast formation are not entirely clear. The present study aimed to investigate the role of ZOL in osteoclast differentiation and function, and to determine whether NF-κB and mitogen-activated protein kinase, and their downstream signalling pathways, are involved in this process. RAW264.7 cells were cultured with RANKL for differentiation into osteoclasts, in either the presence or absence of ZOL. Osteoclast formation was observed by tartrate-resistant acid phosphatase staining and bone resorption pit assays using dentine slices. The expression of osteoclast-specific molecules was analysed using reverse transcription-quantitative polymerase chain reaction and western blotting assays to deduce the molecular mechanisms underlying the role of ZOL in osteoclastogenesis. The results showed that ZOL significantly attenuated osteoclastogenesis and bone resorptive capacity in vitro. ZOL also suppressed the activation of NF-κB and the phosphorylation of c-Jun N-terminal kinase. Furthermore, it inhibited the expression of the downstream factors c-Jun, c-Fos and nuclear factor of activated T cells c1, thereby decreasing the expression of dendritic cell-specific transmembrane protein and other osteoclast-specific markers. In conclusion, ZOL may have therapeutic potential for osteoporosis.

Medication-Related Osteonecrosis of the Jaw Subsequent to Peri-Implantitis: A Case Report and Literature Review

The aim of this report was to document a rare case of medication-related osteonecrosis of the jaw (MRONJ) that developed around the already osseointegrated implants in the maxillary right molar region. A 73-year-old woman presented at our university dental hospital in May 2017 with a chief complaint of discomfort near a maxillary implant. Her first visit was in 2006, and the maintenance treatment began in 2007 after the periodontal treatment. During the implant maintenance period there were no complications; however, the patient began taking alendronate sodium hydrate (Fosamac tablets, 35 mg, once weekly), an oral bisphosphonate (BP) since 2013, for treatment of osteoporosis. Eight years after starting implant maintenance, in 2016, peri-implantitis occurred, for which mechanical cleaning and antimicrobial therapy were performed. Peri-implantitis symptoms disappeared, and the medical condition improved. Nonetheless, in 2017, MRONJ developed 4 years after she commenced taking the BP. The patient underwent implant removal and sequestrectomy. There was no postoperative recurrence. Since it was such a rare case, we performed a literature review but only discovered a few similar cases. Because various triggers may lead to the development of MRONJ, even if already osseointegrated implant, it is important to note that implants in patients taking BPs should be more carefully maintained.

Titanium implant alters the effect of zoledronic acid on the behaviour of endothelial cells

OBJECTIVES

To evaluate the effect of zoledronic acid (ZA) on human umbilical vein endothelial cells (HUVECs) attached to different surfaces.

MATERIALS AND METHODS

A total of three groups were evaluated in this study: sandblasting and acid etching (SLA) + HUVECs; mechanically polished (MP) + HUVECs; and plastic cell culture plates + HUVECs. Scanning electron microscopy, energy-dispersive X-ray spectroscopy, surface roughness and water contact angle were tested for titanium surface characterisation. ZA was added at different concentrations (0, 1, 10, 50 and 100 μM). Cell adhesion, proliferation, viability, apoptosis and gene expression were evaluated.

RESULTS

Mechanically polished and SLA surfaces showed negative effects on cell adhesion and proliferation and promoted cell apoptosis with 100 μM ZA (p < .05). The highest expression of intercellular adhesion molecule-1 (ICAM-1) and angiopoietin-1 was found on SLA surfaces (p < .01). The lowest expression of platelet-endothelial cell adhesion molecule-1 and ICAM-1 was found on MP surfaces (p < .05). A significant decrease in von Willebrand factor was detected on MP and SLA surfaces (p < .001).

CONCLUSIONS

Zoledronic acid has an anti-angiogenic effect on HUVECs attached to titanium implants, while the SLA surface might stimulate HUVECs to express angiogenic and adhesive factor genes despite ZA treatment.

Influence of bisphosphonates on oral implantology: Sodium alendronate and zoledronic acid enhance the synthesis and activity of matrix metalloproteinases by gingival fibroblasts seeded on titanium

OBJECTIVE

This study aimed to assess the influence of the bisphosphonates zoledronic acid and sodium alendronate on MMP-2 and MMP-9 synthesis and activity by gingival fibroblasts seeded onto titanium substrate.

DESIGN

Titanium discs were placed in 24-well cell culture plates and gingival fibroblasts were seeded (1 × 10⁵ cells/discs) on them using Dulbecco's Modified Eagle's Medium (DMEM) + 10 % fetal bovine serum (FBS) for 24 h. After this period, a fresh serum-free DMEM containing zoledronic acid or sodium alendronate at 0.5 μM, 1 μM or 5 μM was applied on the cells for an additional of 24 h. Serum-free DMEM and tumor necrosis factor alpha (TNF-α) were used as negative and positive controls, respectively. MMP-2 and MMP-9 synthesis and activity were determined by ELISA (Enzyme-Linked Immunosorbent Assay) and conventional/in situ zymography. Quantitative data were analyzed by one-way ANOVA and Tukey's tests (α = 0.05). The in situ zymography data were qualitatively described.

RESULTS

Despite both bisphosphonates increased the MMPs synthesis, this effect was significant higher in zoledronic acid groups. MMPs activity resembled by gelatinolytic activity was also enhanced by sodium alendronate and zoledronic acid in a similar pattern.

CONCLUSIONS

Zoledronic acid and sodium alendronate increased in a dose-dependent manner MMP-2 and MMP-9 synthesis by gingival fibroblasts seeded on titanium. MMP-2 activity was up-regulated by zoledronic acid treatment.

Dental implants: a potential cause of bone marrow edema in the jaw-preliminary report

BACKGROUND

Different magnetic resonance imaging (MRI) sequences are frequently used to examine bone marrow in the jaw, including short tau inversion recovery (STIR). MRI is a sensitive method for detecting bone marrow lesions. Currently, pantomography and computed tomography (CT) are used frequently for preoperative dental implant treatment. However, no study has evaluated bone marrow edema around dental implants using MRI. This study aimed to assess bone marrow edema in the jaw around dental implants using brain magnetic resonance images.

METHODS

This retrospective cohort study was approved by our university ethics committee (EC19-011). A total of 17 patients (170 sites) who underwent brain MRI between April 2010 and March 2016 were analyzed. All subjects underwent scanning more than 3 years after implant placement. This study investigated two bone marrow signals (with implant site and without implant site). These two groups were then compared using Fisher's exact test. The Mann-Whitney U test was used to analyze bone marrow signal intensity as the dependent variable and the long and short-axis diameters of the implant as the independent variables.

RESULTS

The were 22/31 sites (71%) and 38/139 sites (27%) of bone marrow edema in the dental implants and without dental implants groups, respectively (p < 0.001). Furthermore, there was a significant correlation between bone marrow signal intensity and the short-axis diameter of the implant (p < 0.001).

CONCLUSION

The signal intensity in the bone marrow sites in the jaw with dental implants was significantly higher than that in the sites without dental implants. The present study findings suggest that dental implants are a potential cause of bone marrow edema in the jaw.

Effects of Bisphosphonates on Osseointegration of Dental Implants in Rabbit Model

This study is to investigate the effect of bisphosphonates on the osseointegration of dental implants in a rabbit model. Twenty female New Zealand White rabbits were equally assigned into control and experiment groups which received saline or zoledronic acid treatment 4 weeks prior to surgery. Titanium dental implant was placed on the calvarial bone. Zoledronic acid or saline treatment continued after surgery for 4 weeks (short-term subgroup) or 8 weeks (long-term subgroup) until sacrifice. Three different fluorochrome labeling solutions were administrated for assessing bone growth rates. Samples of the calvarial bone and mandible were subjected to microcomputed tomography (micro-CT), confocal microscope, and histology analysis. Zoledronic acid treatment significantly reduced bone growth rates in the calvarial bone, but had no significant influence in bone mineral density and trabecular microarchitecture. Significantly lower bone-to-implant contact ratios were found in zoledronic acid-treated animals compared to controls at week 4 but not at week 8. Oncologic dose zoledronic acid suppresses the bone growth rates of the calvarial bone; ZA may have an adverse effect on osseointegration of dental implant in short term, but this effect tends to diminish in long term.

Oral Rehabilitation With Dental Implants and the Importance of a Preventive Evaluation for Osteonecrosis of the Jaws Associated With Medications

Osteonecrosis of the jaw is a possible oral complication resulting from antiresorptive therapies, such as bisphosphonates (Bfs). Although the etiology is not entirely clear, it has been shown to be dependent on several factors, with the traumatic stimulation caused by the placement of teeth implants indicated as one of the predisposing factors to this pathology. The indications and preventive methods for performing these procedures have been questioned, making it essential to determine the proper protocols. Thus, the present study aims to discuss the risks of the development of osteonecrosis in patients undergoing dental implant surgery who use Bfs as well as to discuss related local and systemic factors and possible methods for preventing this side effect. The study also aims to present a clinical case of an osteopenic patient who used Bfs and underwent rehabilitation through implants according to specific protocols, which resulted in successful treatment.

Cone Beam Computed Tomography Imaging in Dental Implants: A Primer for Clinical Radiologists

With the introduction of cone beam computed tomography (CBCT) into dentistry in the 1990s, radiologists have become more frequently involved in dental implant planning. This article describes the information that should be included in a radiology report to achieve a successful implantation. The justification to use CBCT during the preoperative planning phase is based on the need to evaluate patient-specific anatomy in detail (general condition of the jaw, bone quantity, and bone quality), the application of more advanced surgical techniques (maxillary sinus augmentation procedure, zygomatic implants), and the integrated presurgical planning and virtual patient approach. Postoperatively, CBCT is used when implant retrieval is anticipated and two-dimensional radiographs have not provided sufficient information, for evaluation of graft healing, or to assess complications, mostly related to neurovascular trauma.

Enhancement of peri-implant bone formation via parathyroid hormone administration in a rat model at risk for medication-related osteonecrosis of the jaw

Purpose

Dental implant-associated medication-related osteonecrosis of the jaw has been frequently reported in patients administered bisphosphonates (BPs) to prevent osteoporosis. The aim of this study was to investigate the effect of intermittent administration of parathyroid hormone (PTH) on peri-implant bone in the maxillae of ovariectomized rats systemically administered BPs.

Methods

Thirty 8-week-old female Sprague-Dawley rats were randomly divided into 3 groups. The OVX-ZP group included ovariectomized rats administered 60 µg/kg of zoledronate once a week for 6 weeks and 30 µg/kg PTH after implant installation. The OVX-Z group included ovariectomized rats administered 60 µg/kg of zoledronate once a week for 6 weeks and saline after implant installation, and the control group included rats that underwent a sham operation and were then administered saline. Rats were sacrificed 4 weeks after implant placement for histomorphometric and micro-computed tomography (CT) analyses.

Results

The average bone area percentage was greater in the OVX-ZP group than in the OVX-Z group (53.4%±4.0% vs. 28.9%±9.5%, P=0.01). The bone-to-implant contact ratio was 50.8%±1.4% in the OVX-ZP group and 16.9%±2.4% in the OVX-Z group (P=0.012). The average bone volume ratio as shown on micro-CT was 31.3%±19.8% in the OVX-ZP group and 19.4%±9.3% in the OVX-Z group (P=0.045). The OVX-ZP and OVX-Z groups displayed similar trabecular thickness (0.06±0.004 mm vs. 0.06±0.002 mm) (P>0.05) and trabecular separation (0.21±0.02 mm vs. 0.29±0.13 mm) (P>0.05). However, the number of trabeculae in the OVX-ZP group was significantly higher than that in the OVX-Z group (4.3±1.33/mm³ vs. 2.2±0.19/mm³) (P=0.024).

Conclusions

The present findings indicate that intermittently-administered PTH can promote peri-implant bone formation and suggest that PTH administration may aid in effective treatment for medication-related osteonecrosis of the jaw after dental implantation.

Are There Contraindications for Placing Dental Implants?

There are few absolute contraindications to dental implant placement. Relative contraindications include cognitive decline, American Society of Anesthesiology patient status IV or higher categories, or medical conditions that may jeopardize the life or lifespan of the patient. Precautions for placing dental implants should be viewed with respect to the evidence-based exposures that can contribute to risk of failure, including but not limited to local, behavioral, and medical factors. Risk for dental implant failure increases in association with (1) past history of periodontal disease, (2) bruxism, (3) smoking, and (4) radiation therapy.

Chronic osteomyelitis induced by the placement of dental implants on cemento-osseous dysplasia

Cemento-osseous dysplasia is a well-known condition in which healthy bone becomes sclerotic. Hypovascularity of the lesion (caused by cementum-like deposits) increases the risk of secondary infection and osteomyelitis, which can also be induced by the placement of implants.

Impact of bisphosphonate therapy on dental implant outcomes: An overview of systematic review evidence

The purpose of this overview was to assess the methods, quality, and outcomes of systematic reviews conducted to evaluate the impact of bisphosphonates on dental implants and the risk of developing bisphosphonate-related osteonecrosis of the jaw after dental implant surgery. An electronic search without date or language restriction was performed in the PubMed/MEDLINE, Cochrane CENTRAL, Web of Science, and LILACS databases (to January 2018). Eligibility criteria included systematic reviews that evaluated the impact of bisphosphonates on implant outcomes. The quality assessment of the included reviews was done using AMSTAR 2 guidelines. The protocol of this overview was registered in PROSPERO (CRD42018089617). The search and selection process yielded seven reviews, published between 2009 and 2017. None of the systematic reviews included in this study obtained the maximum score in the quality assessment. The scientific evidence available demonstrates that patients with a history of bisphosphonate use do not present a higher risk of dental implant failure or marginal bone loss compared to patients who have not used bisphosphonates. The literature also suggests that patients who undergo surgical trauma during the installation of dental implants may be more susceptible to bisphosphonate-related osteonecrosis of the jaw.

Severe Case of Osteonecrosis Following Implant Placement in a Patient in Therapy With Bisphosphonates: A Case Report

Osteonecrosis of the jaw is a rare complication that has been associated with the use of bisphosphonates. A 77-year-old patient presented in April 2013 asking for a consultation. She reported that in May 2009, she underwent an implant rehabilitation with 8 implants and an immediately loaded fixed prosthesis in the maxilla. After a few months the patient started to report pain and purulent secretions that were neglected by the clinician for several years. She decided to refer to the Dental Clinic after another acute pain episode. Once the fixed prosthesis was removed, exposed necrotic bone was found in relation to the implants. The patient reported having taken oral alendronic acid to treat osteoporosis since before 2006. The patient underwent a functional endoscopic sinus surgery and a removal of necrotic bone blocks. Three years of follow-up showed healed tissues with no recurrence, although the alveolar crest appeared irregular on radiographs.

Dental Implant Placement in Patients on Bisphosphonate Therapy: a Systematic Review

Objectives

The review aims to study dental implant placement purposefulness for patients who have been treated or are on treatment with bisphosphonate medication.

Material and Methods

Structured search strategy was applied on electronic databases: MEDLINE, PubMed, PubMed Central and ResearchGate. Scientific publications in English between 2006 and 2017 were identified in accordance with inclusion, exclusion criteria. Publication screening, data extraction, and quality assessment were performed. Outcome measures included implant failure or implant-related osteonecrosis of the jaw.

Results

In total, 32 literature sources were reviewed, and 9 of the most relevant articles that are suitable to the criteria were selected. Heterogeneity between the studies was found and no meta-analysis could be done. Five studies analysed intraoral bisphosphonate medication in relation with implant placement, three studies investigated intravenous bisphosphonate medication in relation with implant placement and one study evaluated both types of medication given in relation with implant placement. Patients with intraoral therapy appeared to have a better implant survival (5 implants failed out of 423) rate at 98.8% vs. patients treated intravenously (6 implants failed out of 68) at 91%; the control group compared with intraoral bisphosphonate group appeared with 97% success implant survival rate (27 implants failed out of 842), showing no significant difference in terms of success in implant placement.

Conclusions

Patients treated with intravenous bisphosphonates seemed to have a higher chance of developing implant-related osteonecrosis of the jaw. The intraorally treated patient group appeared to have more successful results. Implant placement in patients treated intraorally could be considered safe with precautions.

Development of Antiresorptive Agent-Related Osteonecrosis of the Jaw After Dental Implant Removal: A Case Report

Dental implant treatment is a highly predictable therapy, but when potentially lethal symptoms or complications occur, dentists must remove the implant fixture. Recently, reports on antiresorptive agent-related osteonecrosis of the jaw have increased in the field of dental implants, although the relationship between dental implant treatment and antiresorptive agents remains unclear. Here, we report a case of antiresorptive agent-related osteonecrosis of the jaw that developed after dental implant removal. A 67-year-old Japanese woman with a medical history of osteoporosis and 7 years of oral bisphosphonate treatment was referred to our hospital with a chief complaint of painful right mandibular bone exposure. A family dentist removed the dental implants from the right mandible using a trephine drill without flap elevation in August 2016. However, the healing was impaired; she was referred to our hospital 3 months after the procedure. We performed a sequestrectomy of the mandible under general anesthesia. In conclusion, this patient's course has two important implications: First, the removal of dental implants from patients who are prescribed oral bisphosphonates for long durations can cause antiresorptive agent-related osteonecrosis of the jaw. Second, meticulous procedures are required to prevent and treat the development of antiresorptive agent-related osteonecrosis of the jaw after dental implant removal.

Influence of bisphosphonates on the adherence and metabolism of epithelial cells and gingival fibroblasts to titanium surfaces

OBJECTIVES

To evaluate the effects of sodium alendronate (SA) and zoledronic acid (ZA), on the adhesion and metabolism of epithelial cells and gingival fibroblasts to titanium surfaces considering cell functions related to an effective mucosal barrier around the implant.

MATERIALS AND METHODS

Cells were seeded onto titanium discs and incubated for 24 h. Then, serum-free DMEM containing selected bisphosphonates (0, 0.5, 1, or 5 μM) was added for 24 and 48 h. Factors related to the achievement of an effective mechanical and immunological barrier-cell adhesion, viability, collagen epidermal growth factor, and immunoglobulin synthesis-were evaluated. Data were analyzed by Kruskal-Wallis and Mann-Whitney tests as well as by ANOVA and Tukey's tests, (α = 0.05).

RESULTS

The presence of bisphosphonates culminated in lower cell adhesion to the titanium discs, particularly for SA at 5 μM (40%) and ZA at all concentrations (from 30 to 50%, according to increased concentrations). Reduced cell viability occurred after exposing these cells to ZA (40%); however, only 5 μM SA-treated cells had decreased viability (30%). Reduced synthesis of growth factors and collagen was observed when cells were reated with ZA (20 and 40%, respectively), while about 70% of IgG synthesis was enhanced.

CONCLUSION

Bisphosphonates negatively affected the adhesion and metabolism of oral mucosal cells, and this effect was related to the type of bisphosphonate as well as to concentration and period of treatment.

CLINICAL RELEVANCE

The negative effects of bisphosphonates on oral mucosal cells can hamper the formation of an effective biological seal in osseointegrated implants.

Dental implants in patients treated with antiresorptive medication - a systematic literature review

Objective

Bisphosphonate-associated osteonecrosis of the jaws (BP-ONJ) is triggered by inflammatory processes. Typical trigger factors are periodontal disease, denture pressure sores, and surgical interventions such as tooth extractions. Unfortunately there is only little data on how to proceed with implant therapy in patients with bisphosphonate treatment. This topic is not addressed in the German guidelines on medication-associated osteonecrosis. Therefore a systematic literature review was performed.

Methods

The PICO design was used: (Patients) For which subclientel of patients with antiresorptive therapy (intervention) do dental implants have a benefit (control) compared to forgoing dental implants (outcome) in regards to oral rehabilitation and quality of life without having a substantial risk of BP-ONJ development? A PubMed search was performed including all studies dealing with this topic. Case reports and studies with less than 5 cases were excluded.

Results

There is only very little data available, mostly retrospective case series. 50 articles were analyzed in detail. BP-ONJ can be triggered by dental implants and by dentures in patients with benign and malignant primary diseases. In most studies, analyzing osteoporosis patients only, no cases of BP-ONJ were observed in patients with implant therapy in the time span observed. There are no studies about implant therapy in patients with malignant diseases. Many case series analyzing the trigger factors for BP-ONJ describe dentures as one of the main causes. Perioperative antimicrobial prophylaxis has a benefit in the prevention of BP-ONJ development.

Conclusion

Successful implant therapy is possible in patients receiving antiresorptive therapy. The possibility of osteonecrosis development needs to be explained to the patient. An individual risk assessment is essential, taking the primary disease with the medication and further wound-healing-compromising diseases and medications into account. If possible, bone augmentations should be avoided, and a perioperative antimicrobiological prophylaxis is strongly recommended in these patients.

Assessing the utility of serum C-telopeptide cross-link of type 1 collagen as a predictor of bisphosphonate-related osteonecrosis of the jaw: A systematic review and meta-analysis

BACKGROUND

The authors of this systematic review and meta-analysis assessed the utility of serum C-telopeptide cross-link of type 1 collagen (sCTX), a biomarker of bone resorption, as a predictor of the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ).

TYPES OF STUDIES REVIEWED

The authors searched for studies involving adult participants, written in English, and published through January 20, 2016, using the following electronic databases: the Cochrane Library, MEDLINE via PubMed, and Web of Science. They also searched Google Scholar and the reference lists of all eligible trials and reviews. They identified 16 articles that met their inclusion criteria (9 controlled studies and 7 case series). They applied the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines for systematic reviews and meta-analyses. They independently extracted data in duplicate, including the characteristics of study participants, risk factors, control groups, and outcomes. They assessed risk of bias, and they resolved any disagreements between review authors through discussion.

RESULTS

A meta-analysis with 9 controlled studies revealed no significant difference in mean sCTX values between patients with BRONJ and control participants (difference in means, -31.417; 95% confidence interval [CI], -91.560 to 28.726; P = .306). A second meta-analysis with 4 studies showed no significant difference in risk of having an sCTX value below 150 picograms per milliliter for patients with BRONJ compared with control participants (risk ratio, 1.892; 95% CI, 0.636-5.626; P = .251).

CONCLUSIONS AND PRACTICAL IMPLICATIONS

A systematic review of the literature with meta-analysis does not support the use of sCTX levels as a predictor of the development of BRONJ. Further prospective large sample studies are needed to understand the role of sCTX as a predictor for BRONJ.

Bisphosphonate and Implant Dentistry - Is it Safe?

Bisphosphonates are a group of drugs that are commonly used to alter bone metabolism in order to prevent bone loss in diseases such as osteoporosis and bone cancers. Unfortunately, the use of bisphosphonates has been associated with bisphosphonate-related osteonecrosis of the jaws. The debate as to whether it is wise to consider implant therapy in patients being treated with bisphosphonate therapy remains a grey area. This review will present the latest evidence and guidelines available on bisphosphonates and their possible effects on implant dentistry. The risk factors, co-morbidities, clinical presentation and findings from various imaging modalities for bisphosphonate-related osteonecrosis of the jaws are highlighted. The management of patients being treated with bisphosphonates, in whom dental implants might be considered or have already been placed, will also be discussed. Finally, the areas requiring future research are considered.

Evaluation of dental implants as a risk factor for the development of bisphosphonate-related osteonecrosis of the jaw in breast cancer patients

It remains unclear whether dental implants are a risk factor for the development of bisphosphonate-related osteonecrosis of the jaw (BRONJ). We retrospectively evaluated the status of dental implants in patients given intravenous bisphosphonates (BPs) in a breast cancer cohort to elucidate the risk for BRONJ at the implant site. We established a BRONJ oral monitoring program for 247 breast cancer patients given intravenous BP in our institution. The 3-year cumulative incidence rate was determined. The systemic and local risk factors of 44 patients who completed comprehensive oral examinations were evaluated by logistic regression analysis. The 3-year cumulative incidence rate of the 247 patients was 0.074 % (8/247, 95 % CI 0.0081-0.014). In the 44 orally examined patients, 6 (13.6 %: 6/44) had dental implants. Of these 6 patients, 1 developed BRONJ at the implant site. There were no significant differences in the age, total BP treatment period, number of residual teeth, time of regular oral monitoring, oral hygiene level, or dental implant insertion. Although a case of ONJ was identified, dental implants which were inserted before intravenous BP administration were not a risk factor for the development of ONJ in breast cancer patients.

All-on-4® Treatment Concept for the Rehabilitation of the Completely Edentulous Mandible: A 7-Year Clinical and 5-Year Radiographic Retrospective Case Series with Risk Assessment for Implant Failure and Marginal Bone Level

BACKGROUND

Studies are needed to evaluate long-term outcomes of the All-on-4® treatment concept (Nobel Biocare AB) for rehabilitation of edentulous mandibles by assessing marginal bone levels and risk indicators for implant failure.

PURPOSE

To evaluate 7-year clinical outcomes and 5-year radiographic outcomes of the All-on-4 treatment concept.

MATERIALS AND METHODS

This retrospective case series included patients admitted for implant rehabilitations in the mandible, who were followed for 7 years clinically and 5 years radiographically. Primary outcome measures were cumulative prosthetic and implant survival using patient as the unit of analysis (Kaplan-Meier product limit estimator). Secondary outcome measure was marginal bone level (MBL) at 5 years. Variables associated with implant failure were analyzed using the Cox proportional hazards regression model to calculate hazard ratios (HRs) with 95% confidence intervals (CIs). Binary logistic regression was used to compute odds ratio (OR) with 95% CIs for variables associated with MBL ≥2.8 mm at 5 years.

RESULTS

A total of 324 patients (194 women, 130 men, average age = 58.9 years) were rehabilitated with 1,296 implants supporting 324 full-arch fixed immediately loaded mandibular prostheses. Sixty-four patients (19.8%) were lost to follow-up. Prosthetic survival was 323/324 (99.7%), and 14 patients lost 18 implants, with an estimated cumulative survival rate of 95.4% at 7 years. Variables associated with implant failure were smoking (HR = 5.28; 95% CI: 1.33, 20.91]) and the learning curve effect (0.69 < HR < 0.33 for more experienced levels). Mean MBL at 5 years was 1.81 mm (95% CI: 1.70, 1.92), and smoking was associated with MBL ≥2.8 mm (OR = 2.4; 95% CI: 1.02, 5.62).

CONCLUSIONS

The high implant and prosthetic survival rates and excellent MBL outcome confirm the predictability and safety of the All-on-4 treatment concept over a longer term than previously reported.

Effect of dental implants on bisphosphonate-related osteonecrosis of the jaws

PURPOSE

Bisphosphonate (BP)-related osteonecrosis of the jaw (BRONJ) is a side effect of BP therapy. Dental implants are believed to be a risk factor for developing BRONJ. In the present study, we analyzed the interval to the development of BRONJ in patients treated with BP who had received dental implants.

PATIENTS AND METHODS

Patients with dental implants and established BRONJ were evaluated at the oral and maxillofacial surgery department (Medical University of Vienna). In addition, studies from 1978 to 2012 were included in a meta-analysis. Three groups were created: implantation before BP treatment, implantation after BP treatment, and implantation during BP treatment. The outcomes were evaluated using linear regression analysis.

RESULTS

Patients who underwent dental implantation during (P < .001) and after (P < .001) treatment with BPs developed BRONJ more rapidly. The treatment duration with oral BPs was significantly related to the rapidity of developing BRONJ (P = .03).

CONCLUSIONS

The insertion of dental implants during or after BP treatment accelerated the development of BRONJ. BRONJ occurred less frequently when the implants had been inserted before BP therapy had been started.