Effect of agents affecting bone homeostasis on short- and long-term implant failure

Clinical outcomes and bone marker changes in postmenopausal women with dental implants: a one-year prospective study

OBJECTIVES

The feasibility of dental implants in patients with osteoporosis remains controversial, with limited prospective studies on quantitative changes in bone mineral density (BMD) and bone turnover markers (BTMs). This study assessed implant survival and clinical outcomes while evaluating systemic changes during 1 year of implant treatment.

MATERIALS AND METHODS

Postmenopausal women requiring dental implants were enrolled at the Yonsei University Dental Hospital. BMD and BTMs were evaluated in collaboration with the endocrinology department. Participants were divided into two groups: Group A (T-score ≥ -2) and Group B (T-score < -2). All implants used in the study were surface-treated with hydroxyethyl piperazine ethane sulfonic acid (HEPES), and clinical, radiographic, and systemic parameters were monitored for over 1 year.

RESULTS

Between April 2022 and May 2024, 45 implants were placed in 36 patients (mean age: 68 years). Group A included 17 patients with 21 implants (mean age: 66 years), and Group B included 19 patients with 24 implants (mean age: 70 years). The cumulative survival rate was 100%. Resonance frequency analysis at 12 months revealed a mean implant stability tester value of 71.4 ± 5.52, indicating excellent osseointegration. Peri-implant bone loss averaged 0.54 ± 0.35 mm. No implant failures occurred, with stable plaque scores, probing depths, and bleeding upon probing. BMD and BTMs changes were minimal.

CONCLUSIONS

Both groups achieved high implant survival and stable clinical outcomes. Systemic evaluations confirmed only minor changes in BMD and BTMs over 1 year. Larger multicenter studies are required to confirm the systemic safety of dental implants in patients with osteoporosis.

CLINICAL RELEVANCE

Dental implants show excellent survival and stability in postmenopausal women with osteoporosis, with minimal impact on bone density and turnover-supporting their safe use in this population.

CLINICAL TRIAL REGISTRATION

This study was prospectively registered at the Clinical Research Information Service of the National Research Institute of Health, Republic of Korea (KCT0007100). The registration details can be accessed at https://cris.nih.go.kr .

Analysis of prosthetic risk factors for peri-implant medication-related osteonecrosis of the jaw: an observational study

The study aimed to evaluate clinical characteristics of peri-implant medication-related osteonecrosis of the jaw (PI-MRONJ) and to identify prosthetic risk factors for PI-MRONJ. Demographic and pharmacological data were collected from 32 patients. Radiographic assessments were performed to evaluate potential risk factors related to prosthetic elements, including prosthesis margin, embrasure space, emergence profile and angle, span of prostheses, and cantilever extensions. 24 patients were classified as having implant presence-triggered PI-MRONJ, while 8 were categorized as having implant surgery-triggered PI-MRONJ. Even in well-functioning implants, MRONJ developed after an average of 48.3 months following the initiation of anti-resorptive drug (ARD) therapy. Similarly, in implants placed during ARD therapy and showing successful osseointegration, MRONJ occurred after an average of 23.3 months of implant placement. Comparing prostheses in MRONJ-affected areas to those in unaffected areas, the presence of cantilever extensions showed the only significant difference (p = 0.002). Regression analysis revealed that cantilever extensions (p = 0.001), sex (p = 0.009), duration of ARD (p = 0.042), and age (p = 0.046) were significantly associated with PI-MRONJ. These findings suggest that non-axial loading may be a risk factor for PI-MRONJ. Proper prosthetic design and load management, along with long-term monitoring, are crucial for preventing PI-MRONJ.

USP7 Inhibition Promotes Early Osseointegration in Senile Osteoporotic Mice

Although elderly osteoporotic patients have similar implant survival rates compared with those of normal individuals, they require longer healing periods to achieve proper osseointegration. This may be related to chronic inflammatory responses and impaired stem cell repair functions in the osteoporotic bone microenvironment. Recently, the deubiquitinating enzyme, ubiquitin-specific peptidase 7 (USP7), was found to regulate the macrophage immune response and modulate stem cell osteogenic differentiation. The selective inhibitor of USP7, P5091, has also been found to promote bone repair and homeostasis in osteoporotic conditions. However, the roles of USP7 and P5091 in osteoimmunology and dental implant osseointegration under senile osteoporotic conditions remain unclear. In this study, USP7 depletion and P5091 were shown to inhibit inflammation in senescent bone marrow-derived macrophages (BMDMs) and promote osteogenic differentiation in aged bone marrow mesenchymal stromal cells (BMSCs). Furthermore, mRNA-Seq revealed that USP7 depletion could enhance efferocytosis in senescent BMDMs through the EPSIN1/low-density lipoprotein receptor-related protein 1 (LRP1) pathway and selectively induce apoptosis (senolysis) in aged BMSCs. In senile osteoporotic mice, we found that the osseointegration period was prolonged compared with young mice, and P5091 promoted the early stage of osseointegration, which may be related to macrophage efferocytosis around the implant. Collectively, this study suggests that USP7 inhibition may accelerate the osseointegration process in senile osteoporotic conditions by promoting macrophage efferocytosis and aged BMSCs apoptosis. This has implications for understanding the cellular interactions and signaling mechanisms in the peri-implant bone microenvironment under osteoporotic conditions. It may also provide clinical significance in developing new therapies to enhance osseointegration quality and shorten the edentulous period in elderly osteoporotic patients.

Annual review of selected scientific literature: A report of the Committee on Scientific Investigation of the American Academy of Restorative Dentistry

The Scientific Investigation Committee of the American Academy of Restorative Dentistry offers this review of select 2023 dental literature to briefly touch on several topics of interest to modern restorative dentistry. Each committee member brings discipline-specific expertize in their subject areas that include (in order of appearance here): prosthodontics; periodontics, alveolar bone, and peri-implant tissues; dental materials and therapeutics; occlusion and temporomandibular disorders; sleep-related breathing disorders; oral medicine, oral and maxillofacial surgery, and oral radiology; and dental caries and cariology. The authors have focused their efforts on presenting information likely to influence the daily dental treatment decisions of the reader with an emphasis on current innovations, new materials and processes, emerging technology, and future trends in dentistry. With the overwhelming volume of literature published daily in dentistry and related disciplines, this review cannot be comprehensive. Instead, its purpose is to inform and update interested readers and provide valuable resource material for those willing to subsequently pursue greater detail on their own. Our intent remains to assist colleagues in navigating the tremendous volume of newly minted information produced annually. Finally, we hope readers find this work helpful in providing evidence-based care to patients seeking healthier and happier lives.

Medications Affecting Treatment Outcomes in Dentistry: Part 2

Today, it is common for medically complex patients who are receiving multiple medications, to seek routine and emergent dental care. It is essential for the practitioner to recognize and comprehend the impact of such medications on the patient's ability to tolerate the planned dental treatment and on dental treatment outcomes. An active appraisal of current literature is essential to stay abreast of emerging findings and understand their treatment implications. This article outlines the process of such active critical appraisal, illustrating key paradigms of the models that describe the impact of medications on treatment outcomes.

Implant presence-triggered osteonecrosis: A scoping review

Unlike medication-related osteonecrosis of the jaw (MRONJ), implant presence-triggered osteonecrosis of the jaw (IPTO) is not well appreciated. Recent reports have suggested a mechanical aetiology unique to osseointegrated dental implants that may be responsible for this phenomenon. A scoping review was performed to consolidate the available evidence. Two reviewers independently searched the PubMed, EMBASE, CINAHL, and Cochrane Library databases. The study was performed according to the Preferred Reporting Items for Systematic Review and Meta-Analyses (PRISMA) extension for scoping reviews. Studies that described or evaluated the development of IPTO in osseointegrated implants, which were placed prior to the commencement of anti-resorptive or anti-angiogenic agents, were included. Twenty-three (23) articles were included in this study. Patient characteristics, aetiopathogenesis, presentation, and treatment of the disease were evaluated. Most studies suggested a 6-month period between dental implant insertion and the commencement of anti-resorptive therapy as a criterion for IPTO. Both infective and mechanical processes were reported to be involved in the pathogenesis of IPTO. Most patients required surgical intervention to achieve resolution. While there are several knowledge gaps regarding IPTO, the evidence points towards a continuum in the pathogenesis of the disease, whereby there is a mechanical cause followed by secondary infection. Similar to typical MRONJ, the severity and treatment required also vary. Persistent peri‑implantitis features around a dental implant should alert the clinician to the possibility of IPTO in patients taking anti-resorptive or anti-angiogenic agents. Prompt identification of the disease may play a role in timely management or appropriate referrals.

Comparison of the effects of submucosal hyaluronidase and dexamethasone on postoperative edema, pain, trismus, and infection following impacted third molar surgery

BACKGROUND

Limiting postoperative edema, pain, trismus, and infection is crucial for smooth healing. This prospective, controlled clinical trial investigated and compared the effectiveness of dexamethasone and hyaluronidase in relieving these complications.

METHODS

In groups Ia and IIa, 8 mg of dexamethasone and 150 IU of hyaluronidase were administered following the removal of impacted teeth, respectively. The contralateral sides (groups Ib and IIb) were determined as control groups. Edema, pain, trismus, and infection were clinically evaluated on the 1st, 2nd, 3rd, and 7th postoperative days.

RESULTS

60 patients were enrolled in the study. Hyaluronidase provided significantly more edema relief than dexamethasone on the 1st, 2nd, 3rd, and 7th postoperative days (P = 0.031, 0.002, 0.000, and 0.009, respectively). No statistical difference was found between dexamethasone and hyaluronidase in VAS and rescue analgesic intake amount values for all time points. Hyaluronidase was more effective in reducing trismus than dexamethasone on the 2nd and 3rd postoperative days (P = 0.029, 0.024, respectively). Neither of the agents significantly increased the postoperative infection rate.

CONCLUSIONS

Hyaluronidase can be selected when postoperative excessive edema and trismus are anticipated. Dexamethasone may be a cost-effective option if postoperative pain control is merely targeted.

TRIAL REGISTRATION

This trial was registered in the Clinical Trials Protocol Registration and Results System (ClinicalTrials.gov identifier number: NCT05466604) on 20/07/2022.

Tooth- and implant-related prognostic factors in treatment planning

Following a comprehensive patient examination, including the assessment of periodontal and peri-implant diseases as well as considering the patient's needs, a pretherapeutic prognosis for each tooth and implant is given. Teeth and implants with a secure pretherapeutic prognosis require simple procedures and may be regarded as secure abutments for function and with a doubtful pretherapeutic prognosis usually need a comprehensive therapy. Such teeth and implants must be brought into the category with a secure prognosis by means of additional therapy such as endodontic, restorative, and surgical procedures. Teeth and implants with a hopeless pretherapeutic prognosis should be extracted/explanted during the initial phase of cause-related therapy (i.e., infection control). For example, teeth with vertical root fracture or unrestorable caries and implants with mobility or unrestorable malposition fall into the category of hopeless units. The primary goal of periodontal and peri-implant therapy should be to arrest disease progression. The latest consensus statement highlights that periodontitis can be successfully controlled and treated teeth can be retained for life. Nevertheless, for patients with uncontrolled contributing factors, the endpoints might not always be achievable, and low disease activity may be an acceptable therapeutic goal. Similarly, the management of peri-implantitis frequently requires surgical intervention following nonsurgical therapy due to incomplete treatment outcomes. Different surgical modalities can be effective and lead to significant improvement; however, achieving complete resolution of peri-implantitis is challenging, not always predictable, and can depend on multiple baseline factors. Therefore, this review aims at summarising available evidence on the rationale for incorporating systemic, lifestyle-related, clinical, and radiographic prognostic factors into treatment planning of patients diagnosed with periodontal and peri-implant diseases.

Biomechanical analysis of alveolar bones with compromised quality supporting a 4-unit implant bridge; a possible association with implant-related sequestration (IRS)

OBJECTIVES

This study aimed to investigate the strain in the bone surrounding dental implants supporting a 4-unit bridge and assess the role of excessive strain as a possible risk factor for implant related sequestration (IRS) or peri-implant medication-related osteonecrosis of the jaw (PI-MRONJ).

MATERIALS AND METHODS

A 3D-mandibular model was constructed using computed tomography and segmented it into cortical and cancellous bones. The 4-unit implant-supported bridges replacing the mandibular posteriors were constructed, and each featuring two, three, and four implants, respectively. The Young's modulus was assigned based on the quality of the bone. A maximum occlusal force of 200 N was applied to each implant in the axial and in a 30-degree oblique direction.

RESULTS

The maximum principal strain of the fatigue failure range (> 3000 µε) in the bone was analyzed. The volume fraction of fatigue failure was higher in poor-quality bone compared to normal bone and oblique load than in axial load. An increasing number of implants may dissipate excessive strain in poor-quality bones.

CONCLUSIONS

Occlusal force applied to poor-quality bone can result in microdamage. Given that unrepaired microdamage may initiate medication-related osteonecrosis of the jaw, long-term occlusal force on fragile bones might be a risk factor.

CLINICAL RELEVANCE

When planning implant treatment for patients with compromised bone status, clinical modifications such as strategic placement of implants and optimization of restoration morphology should be considered to reduce excessive strain which might be associated with IRS or PI-MRONJ.

A Mapping Review of the Pathogenesis of Peri-Implantitis: The Biofilm-Mediated Inflammation and Bone Dysregulation (BIND) Hypothesis

This mapping review highlights the need for a new paradigm in the understanding of peri-implantitis pathogenesis. The biofilm-mediated inflammation and bone dysregulation (BIND) hypothesis is proposed, focusing on the relationship between biofilm, inflammation, and bone biology. The close interactions between immune and bone cells are discussed, with multiple stable states likely existing between clinically observable definitions of peri-implant health and peri-implantitis. The framework presented aims to explain the transition from health to disease as a staged and incremental process, where multiple factors contribute to distinct steps towards a tipping point where disease is manifested clinically. These steps might be reached in different ways in different patients and may constitute highly individualised paths. Notably, factors affecting the underlying biology are identified in the pathogenesis of peri-implantitis, highlighting that disruptions to the host-microbe homeostasis at the implant-mucosa interface may not be the sole factor. An improved understanding of disease pathogenesis will allow for intervention on multiple levels and a personalised treatment approach. Further research areas are identified, such as the use of novel biomarkers to detect changes in macrophage polarisation and activation status, and bone turnover.