Elements of Implant-Supported Rehabilitation Planning in Patients With Bruxism:

Biomechanical effects of different materials for an occlusal device on implant-supported rehabilitation in a tooth clenching situation: A 3D finite element analysis

PURPOSE

The purpose of this 3D finite element analysis was to evaluate the biomechanical effects of different materials used to fabricate occlusal devices to achieve stress distribution in simulated abutment screws, dental implants, and peri-implant bone tissue in individuals who clench their teeth.

MATERIALS AND METHODS

Eight 3D models simulated a posterior maxillary bone block with three external hexagon implants (Ø4.0 × 7.0 mm) supporting a 3-unit screw-retained metal-ceramic prosthesis with different crown connection (splinting), and the use of an occlusal device (OD). The OD was modeled to be 2-mm thick. ANSYS 19.2 software was used to generate the finite-element models in the pre-and post-processing phases. Simulated abutment screws and dental implants were evaluated by von Mises stress maps, and simulated bone was evaluated by maximum principal stress and microstrain maps by using a finite element software program.

RESULTS

The highest stress values in the dental implants and screws were observed in single crowns without OD (M1). Furthermore, the highest stress values and bone tissue strain were found in single crowns without OD (M1). The simulated material for the OD did not cause many discrepancies in terms of the stress magnitude in the simulated dental implant and abutment screw for both single and splinted crowns; however, more rigid materials exhibited lower stress values.

CONCLUSION

The use of OD was effective in reducing stress in the simulated implants and abutment screws and stress and strain in the simulated bone tissue. The material used to simulate the OD influenced the biomechanical behavior of implant-supported fixed prostheses, whereas splints with rigid materials such as PEEK and PMMA exhibited better biomechanical behavior.

Prosthetic complications and failures of implant-supported fixed partial dentures: A scoping review

STATEMENT OF PROBLEM

Although high survival rates of implant-supported fixed partial dentures (ISFPDs) have been reported, evidence for complications, failures, and factors that interfere with their longevity is lacking.

PURPOSE

The purpose of this scoping review was to review the literature to investigate the most common failures and complications of ISFPDs.

MATERIAL AND METHODS

This review followed the preferred reporting items for systematic reviews and meta-analyses scoping review (PRISMA ScR) guidelines, and the methodology was registered on the open science framework (osf.io/5xqkp). An electronic search was conducted in PubMed/MEDLINE, Embase, Cochrane Library, Scopus, and Web of Science databases and nonpeer-reviewed literature for articles published from 2013 to January 2023. Studies that evaluated the clinical performance of ISFPDs with at least 1 year of follow-up and described the concepts of failure and success were included.

RESULTS

The search yielded 5695 studies. Fourteen articles were included in this review for data extraction. Veneering porcelain fracture, screw fracture, and implant loss were the most common failures reported. Technical complications mainly involved screw loosening, loss of retention, and wear of the screw-access restoration.

CONCLUSIONS

Bruxism, mismatch of the thermal expansion coefficient, unsatisfactory support of the framework, choice of cement, shape of the titanium abutments, and extended length of the cantilever were associated with the longevity of the ISFPD. Despite the high survival rate of ISFPDs, data must be carefully interpreted because of the variation in the materials used to manufacture the ISFPD and the heterogeneity of the studies in this review.

Dental Implant Treatment in Bruxers: A Case Report and Literature Review

This case report presents a literature review and a case report of a full-mouth implant rehabilitation for a 65-year-old woman with a history of Bruxism. The patient's oral condition showed dentition with severe occlusal wear, extensive dental work, and missing teeth replaced with bridges and implants. The existing dental work was failing due to recurrent caries and the mechanical failure of long-span bridges. The unique aspect of the treatment presented in this report is the management of existing osseointegrated implants of different systems with different platform designs, which adds to the treatment's complexity. The existing implants were incorporated into the planned treatment, and other implants were added to support maxillary zirconia and mandibular hybrid full-arch prostheses. After 2 years of function, extensive wear was evident on the milled acrylic, even though an occlusal guard was used. New acrylic teeth were processed using the same milled titanium bar of the mandibular hybrid prosthesis, and the occlusal surfaces of the acrylic teeth were protected with gold onlays. The patient is seen regularly for maintenance every 6 months with no further complications. Careful evaluation, planning, and treatment execution are paramount in managing patients with a history of bruxism. Patients should be prepared and informed about possible mechanical failure and seen regularly for maintenance.

Analysis of divergence between the axes of dental implants installed using a classic freehand technique

Accuracy is a common challenge in dental implant placement. A successful clinical outcome is largely determined by accurate positioning of the implant at the prepared site and proper angulation. This study aimed to compare the divergence between the axes of the implants installed using a classic freehand technique. Cartesian coordinates of implant necks were determined on the CT images of 34 patients in the XOY (horizontal) plane, followed by the coordinates of implant apices. The obtained data were submitted to the original software developed by the authors (patent 2018661716) that automatically computed an angle between the insertion axes of the installed implants. We found that in 87% of cases, this angle was significantly greater (up to 27°) than recommended by implantation dentistry guidelines (7°). In 100% of the studied cases, the implants were not parallel; in sector 1, the deviation was 27° 4`.

Immediate Loading of Tapered Implants Placed in Postextraction Sockets and Healed Sites

OBJECTIVE

The aim of the present study was to compare the survival, stability, and complications of immediately loaded implants placed in postextraction sockets and healed sites.

METHODS

Over a 2-year period, all patients presenting with partial or complete edentulism of the maxilla and/or mandible (healed site group, at least 4 months of healing after tooth extraction) or in need of replacement of nonrecoverable failing teeth (postextraction group) were considered for inclusion in this study. Tapered implants featuring a nanostructured calcium-incorporated surface were placed and loaded immediately. The prosthetic restorations comprised single crowns, fixed partial dentures, and fixed full arches. Primary outcomes were implant survival, stability, and complications. Implant stability was assessed at placement and at each follow-up evaluation (1 week, 3 months, and 1 year after placement): implants with an insertion torque (IT) <45 N·cm and/or with an implant stability quotient (ISQ) <70 were considered failed for immediate loading. A statistical analysis was performed.

RESULTS

Thirty implants were placed in postextraction sockets of 17 patients, and 32 implants were placed in healed sites of 22 patients. There were no statistically significant differences in ISQ values between the 2 groups, at each assessment. In total, 60 implants (96.8%) had an IT ≥45 and an ISQ ≥70 at placement and at each follow-up control: all these implants were successfully loaded. Only 2 implants (1 in a postextraction socket and 1 in a healed site, 3.2%) could not achieve an IT ≥45 N·cm and/or an ISQ ≥70 at placement or over time: accordingly, these were considered failed for stability, as they could not be subjected to immediate loading. One of these 2 implants, in a healed site of a posterior maxilla, had to be removed, yielding an overall 1-year implant survival rate of 98.4%. No complications were reported. No significant differences were reported between the 2 groups with respect to implant failures and complications.

CONCLUSION

Immediately loaded implants placed in postextraction sockets and healed sites had similar high survival and stability, with no reported complications. Further long-term studies on larger samples of patients are needed to confirm these results.

Therapies for bruxism: a systematic review and network meta-analysis (protocol)

BACKGROUND

Bruxism is a sleep disorder characterized by grinding and clenching of the teeth that may be related to irreversible tooth injuries. It is a prevalent condition occurring in up to 31% of adults. However, there is no definitive answer as to which of the many currently available treatments (including drug therapy, intramuscular injections, physiotherapy, biofeedback, kinesiotherapy, use of intraoral devices, or psychological therapy) is the best for the clinical management of the different manifestations of bruxism. The aim of this systematic review and network meta-analysis is to answer the following question: what is the best treatment for adult bruxists?

METHODS/DESIGN

Comprehensive searches of the Cochrane Library, MEDLINE (via PubMed), Scopus, and LILACS will be completed using the following keywords: bruxism and therapies and related entry terms. Studies will be included, according to the eligibility criteria (Controlled Clinical Trials and Randomized Clinical Trials, considering specific outcome measures for bruxism). The reference lists of included studies will be hand searched. Relevant data will be extracted from included studies using a specially designed data extraction sheet. Risk of bias of the included studies will be assessed, and the overall strength of the evidence will be summarized (i.e., GRADE). A random effects model will be used for all pairwise meta-analyses (with a 95% confidence interval). A Bayesian network meta-analysis will explore the relative benefits between the various treatments. The review will be reported using the Preferred Reporting Items for Systematic Reviews incorporating Network Meta-Analyses (PRISMA-NMA) statement.

DISCUSSION

This systematic review aims at identifying and evaluating therapies to treat bruxism. This systematic review may lead to several recommendations, for both patients and researchers, as which is the best therapy for a specific patient case and how future studies need to be designed, considering what is available now and what is the reality of the patient.

SYSTEMATIC REVIEW REGISTRATION

PROSPERO CRD42015023308.

Psychosocial aspects of bruxism: the most paramount factor influencing teeth grinding

In clinical practice, patients suffering from an occlusal parafunctional activity have increased. It can be observed that a negative influence of environment aggravates patient's health. The aim of this paper is to present the impact of environment and development of human civilization on the prevalence of bruxism and the correlation between them. The authors grasp the most relevant aspects of psychological and anthropological factors changing over time as well as their interactions and describe a relationship between chronic stress and bruxism. Current literature shows how contemporary lifestyle, working environment, diet, and habits influence the patient's psychoemotional situation and the way these factors affect the occluso-muscle condition.

Occlusion for implant-supported fixed dental prostheses in partially edentulous patients: a literature review and current concepts

Implant treatment has become the treatment of choice to replace missing teeth in partially edentulous areas. Dental implants present different biological and biomechanical characteristics than natural teeth. Occlusion is considered to be one of the most important factors contributing to implant success. Most literature on implant occlusal concepts is based on expert opinion, anecdotal experiences, in vitro and animal studies, and only limited clinical research. Furthermore, scientific literature regarding implant occlusion, particularly in implant-supported fixed dental prostheses remains controversial. In this study, the current status of implant occlusion was reviewed and discussed. Further randomized clinical research to investigate the correlation between implant occlusion, the implant success rate, and its risk factors is warranted to determine best clinical practices.