Bacterial leakage and bending moments of screw-retained, composite-veneered PEEK implant crowns

Assessment of Polyetheretherketone Crown in Patients: An Original Research

Introduction

Polyetheretherketone (PEEK) has a long history of usage in implant abutments, but it has not seen much applications in tooth-supported prosthetics. The purpose of this research was to examine the clinical performance of PEEK crowns as well as the level of patient satisfaction with them. The pilot study was designed as an in vivo longitudinal examination.

Material and Methods

Twenty patients each received a PEEK crown during the procedure. In total, 22 implants were inserted, with 11 going into the maxilla and 9 into the mandible. One operator was responsible for carrying out each phase of the procedure. The resin cement was used to lute the crowns that were produced. Baseline, 3 months, 6 months, and 1 year after the crowns were placed, they were evaluated for various parameters using Modified Ryge's Criteria. These evaluations were performed at intervals of 3 months, 6 months, and 1 year. In addition, a questionnaire was used at the same time to assess the level of satisfaction felt by patients. Fisher's exact test was utilized in the process of analyzing the data that were gathered.

Results

According to the findings, 92.5% of the crowns met the modified version of Ryge's criterion for a satisfactory rating. Three crowns had a fracture recorded. There was some chipping off observed in five of the crowns. There was not any significant difference in the other factors that were examined. The periodontal health of these three patients showed a slight degree of variance (P = 0.02).

Conclusion

The capacity of PEEK crowns to create high-quality prostheses that were deemed satisfactory with a reasonably low rate of fracture during the relative mean duration of 1 year was established by the application of Modified Ryge's Criteria. The PEEK crowns demonstrated their ability to produce quality prostheses.

Complete-arch implant-supported fixed dental prostheses fabricated with PEEK and PEKK framework: a systematic review

PURPOSE

To evaluate the performance of complete-arch implant-supported fixed dental prostheses (FDPs) fabricated with polyetheretherketone (PEEK) and polyetherketoneketone (PEKK) framework in clinical cases.

MATERIALS AND METHODS

This systematic review followed the guidelines of Preferred Reporting Items for Systematic Reviews and Meta-Analyses and was registered in the International Prospective Register of Systematic Reviews with the number CRD42023399494. The electronic database PubMed, Cochrane Library and EBSCOhost were assessed for clinical research and reports on complete-arch implant-supported FDPs fabricated with PEEK and PEKK framework. Human studies with a minimum follow-up of 1 year and published in an English language were the only ones included.

RESULTS

The initial database and hand search provided 564 articles. Finally, 12 articles published between 2018 and 2022 were included in this systematic review. The mean follow-up ranged from 1 year to 6 years. The included studies reported 119 (114 PEEK, 5 PEKK) complete-arch implant-supported FDPs during 1 year follow-up. The cumulative survival rate of prostheses with PEEK as a framework was 97.3%. Prostheses fractures and complications were found with both PEEK and PEKK frameworks. No implant failure reported with both PEEK and PEKK prostheses.

CONCLUSION

In short-term follow-up, the complete-arch implant-supported FDPs with PEEK as a framework showed a good survival rate and acceptable health of the supporting tissues. The PEEK framework had shown adhesion issues as the most common prosthetic complication. Limited data were available on PEKK as framework material, so further long-term clinical trials are required.

Microleakage along the implant-abutment interface: a systematic review and meta-analysis of in vitro studies

PURPOSE

This systematic review aimed to evaluate the incidence of microleakage events (IME) and to identify the potential factors influencing the sealing ability of the implant-abutment interface (IAI) under in vitro investigation.

MATERIAL AND METHODS

An electronic search of MEDLINE (PubMed), EMBASE, and Web of Science databases, combined with a manual literature search was conducted up to September 2022. In vitro studies that reported the degree of microleakage at IAI under dynamic loading conditions were included. A meta-analysis was performed to calculate the mean values of the incidence of microleakage events. Subgroup analysis and meta-regression were conducted to further investigate the effect of different variables.

RESULTS

675 studies were identified following the search process and 17 in vitro studies were selected according to the eligibility criteria. The weighted mean incidence of microleakage events was 47% (95% confidence interval: [0.33, 0.60]), indicating that contamination was observed in nearly half of the samples. Concerning possible factors that may influence microleakage (e.g., loading condition, assessment method, implant-abutment connection design, types of abutment material, the use of sealing agents), loading condition (p = 0.016) was the only variable that significantly influenced IME in the meta-regression analysis.

CONCLUSIONS

The results demonstrated that dynamic loading significantly increases the potential of bacterial penetration at the implant-abutment junction. The results should be interpreted carefully due to the data heterogeneity and further well-conducted in vitro studies with homogeneous samples are needed to standardize the methodologies.

Description of Poly(aryl-ether-ketone) Materials (PAEKs), Polyetheretherketone (PEEK) and Polyetherketoneketone (PEKK) for Application as a Dental Material: A Materials Science Review

Poly(aryl-ether-ketone) materials (PAEKs), a class of high-performance polymers comprised of polyetheretherketone (PEEK) and polyetherketoneketone (PEKK), have attracted interest in standard dental procedures due to their inherent characteristics in terms of mechanical and biological properties. Polyetheretherketone (PEEK) is a restorative dental material widely used for prosthetic frameworks due to its superior physical, mechanical, aesthetic, and handling features. Meanwhile, polyetherketoneketone (PEKK) is a semi-crystalline thermoplastic embraced in the additive manufacturing market. In the present review study, a new way to fabricate high-performance polymers, particularly PEEK and PEKK, is demonstrated using additive manufacturing digital dental technology, or 3-dimensional (3D) printing. The focus in this literature review will encompass an investigation of the chemical, mechanical, and biological properties of HPPs, particularly PEEK and PEKK, along with their application particularly in dentistry. High-performance polymers have gained popularity in denture prosthesis in advance dentistry due to their flexibility in terms of manufacturing and the growing interest in utilizing additive manufacturing in denture fabrication. Further, this review also explores the literature regarding the properties of high-performance polymers (HPP) compared to previous reported polymers in terms of the dental material along with the current advancement of the digital designing and manufacturing.

Double-Crown Prosthesis Retention Using Polyetherketoneketone (PEKK): An In Vitro Study

PURPOSE

To assess the retentive force of telescopic crowns using polyetherketoneketone (PEKK) high-performance polymer in relation to conventional materials over a long period of time in an in vitro setting.

MATERIALS AND METHODS

Thirty-six sets of primary and secondary crowns were fabricated as per the double crown-retained prostheses approach. Six samples were included in each of the five test groups (1: zirconia/PEKK [Zr/PEKK]; 2: titanium/PEKK [Ti/PEKK]; 3: cobalt-chrome/PEKK [CoCr/PEKK]; 4: PEKK/PEKK; and 5: gold/PEKK [Au/PEKK]) and the single control group (gold/galvano-gold [Au/GA]). The insertion-removal test was performed for 20,000 cycles, and the surface condition was observed. Retentive forces were analyzed using two-way ANOVA (α<0.05).

RESULTS

The retention forces in groups Zr/PEKK and Ti/PEKK significantly decreased over time (group 1: p = 0.035 and group 2: p = 0.001), whereas retentive force increased significantly in groups PEKK/PEKK, Au/PEKK, and control (group 4: p = 0.001, group 5: p = 0.008, and control: p = 0.042). Similar wear was observed on the primary crown in groups PEKK/PEKK, gold/PEKK, and control.

CONCLUSIONS

Groups PEKK/PEKK and Au/PEKK showed a transition of retentive force similar to the control group. Groups PEKK/PEKK and Au/PEKK had similar wear on the surface compared to control. Therefore, PEKK has a promising clinical potential.

Microbiological analysis of bacterial sealing of internal conical implants with different taper angles

The present study evaluated the effect of the taper angle of different internal conical connection implants and cyclic loading on the implant-abutment bacterial seal. A total of 96 implant-abutment sets were divided into eight groups. Four groups of different taper degrees with cyclic mechanical loading of 500,000 cycles per sample, with a 120-N load at 2 Hz before analysis [16DC (16-degree, cycled), 11.5DC (11.5-degree, cycled), 3DC (3- degree, cycled) and 4DC (4- degree, cycled)] were compared to four control groups without cyclic loading [16D (16-degree), 11.5D (11.5-degree), 3D (3-degree), and 4D (4-degree)]. Microbiological analysis was performed by immersing all samples in a suspension containing Escherichia coli and incubating them at 37°C. After 14 days, the presence of bacterial seals was evaluated. Fisher-Freeman-Halton exact tests and binomial tests were performed (5% significance level). The groups showed significant differences in bacterial seal, and mechanical load cycling improved the bacterial seal in the 3DC group. In all other groups, no significant differences in bacterial seal were found between cycled and uncycled samples. To conclude, the internal conical connection with a 3-degree taper angle showed better results than the other connection with different angles when subjected to load cycling. However, none of the angles tested were fully effective in sealing the implant-abutment interface.

The impact of Morse taper implant design on microleakage at implant-healing abutment interface

The microbial leakage at the implant-abutment interface (IAI) is one cause of peri-implant infection that puts long-term implant stability at risk. The present study compared two types of Morse taper implants in terms of sealing performance at the implanthealing abutment interface. Three implant systems, one of which exhibited a partial face-contact design (TSO) and the other two a line-contact design (TSM and BLT), were analyzed in vitro using two quantitative implant leakage measuring techniques: air-injection pressure measurement test and microbial examination. An in-house-developed device was used to determine implant leakage by recording the initial drop in pressure while injecting air through the implant. The microbial examination measured the absorbances of culture mediums in which the inoculated implants were contained. Significant difference was found between the partial face- and line-contact groups (p<0.001). Both tests revealed that partial face-contact implants are more prone to leakage than line-contact implants.

PEEK Biomaterial in Long-Term Provisional Implant Restorations: A Review

Polyetheretherketone (PEEK) has become a useful polymeric biomaterial due to its superior properties and has been increasingly used in dentistry, especially in prosthetic dentistry and dental implantology. Promising applications of PEEK in dentistry are dental implants, temporary abutment, implant-supported provisional crowns, fixed prosthesis, removable denture framework, and finger prosthesis. PEEK as a long-term provisional implant restoration has not been studied much. Hence, this review article aims to review PEEK as a long-term provisional implant restoration for applications focusing on implant dentistry. Articles published in English on PEEK biomaterial for long-term provisional implant restoration were searched in Google Scholar, ScienceDirect, PubMed/MEDLINE, and Scopus. Then, relevant articles were selected and included in this literature review. PEEK presents suitable properties for various implant components in implant dentistry, including temporary and long-term provisional restorations. The modifications of PEEK result in wider applications in clinical dentistry. The PEEK reinforced by 30-50% carbon fibers can be a suitable material for the various implant components in dentistry.

Polyetheretherketone versus titanium CAD-CAM framework for implant-supported fixed complete dentures: a retrospective study with up to 5-year follow-up

PURPOSE

To evaluate the performance of polyetheretherketone (PEEK) versus titanium computer-aided designed and manufactured (CAD-CAM) framework for implant-supported fixed complete dentures (ISFCDs) with a follow-up for a duration of up to 5 years.

METHODS

Consecutively edentulous patients who underwent ISFCDs with a PEEK framework or titanium framework at one dental specialist center were included in this retrospective study. Implant/prosthesis survival rates, mechanical/biological complications, and bone and soft tissue parameters were analyzed. Overall survival was analyzed using Kaplan-Meier survival curves and the log-rank test.

RESULTS

Sixty ISFCDs (29 PEEK, 31 titanium) performed on 43 edentulous patients (331 implants) were included. An implant survival rate of 100% was obtained. There was no significant difference in the cumulative prosthesis survival rate between the PEEK (93.1%) and titanium groups (93.5%). The most common mechanical complications were fracture of the artificial veneer in both the PEEK (13.8%) and titanium (16.7%) groups. Bruxers had a higher prevalence of mechanical complications than non-bruxers (p<0.05). The biological complications included bleeding upon probing (13.8% for the PEEK group; 16.1% for the titanium group), soft tissue inflammation (3.4% for the PEEK group; 3.2% for the titanium group), and temporomandibular disorders (6.5% for the titanium group). The vertical bone loss was significantly lower in the PEEK group (0.70 mm) than in the titanium group (0.96 mm). Smokers had a significantly higher prevalence of biological complications than non-smokers.

CONCLUSIONS

Within the limitations of this study, ISFCDs with PEEK frameworks can provide good prognosis for edentulous patients, still requiring longer-term validation.

Review on Development and Dental Applications of Polyetheretherketone-Based Biomaterials and Restorations

Polyetheretherketone (PEEK) is an important high-performance thermoplastic. Its excellent strength, stiffness, toughness, fatigue resistance, biocompatibility, chemical stability and radiolucency have made PEEK attractive in dental and orthopedic applications. However, PEEK has an inherently hydrophobic and chemically inert surface, which has restricted its widespread use in clinical applications, especially in bonding with dental resin composites. Cutting edge research on novel methods to improve PEEK applications in dentistry, including oral implant, prosthodontics and orthodontics, is reviewed in this article. In addition, this article also discusses innovative surface modifications of PEEK, which are a focus area of active investigations. Furthermore, this article also discusses the necessary future studies and clinical trials for the use of PEEK in the human oral environment to investigate its feasibility and long-term performance.

The use of PEEK in digital prosthodontics: A narrative review

Background

Advanced computer-aided design and computer-aided manufacturing (CAD-CAM) technology led to the introduction of an increasing number of machinable materials suitable for dental prostheses. One of these materials is polyetheretherketone (PEEK), a high performance polymer recently used in dentistry with favorable physical, mechanical and chemical properties. The purpose of this study was to review the current published literature on the use of PEEK for the fabrication of dental prostheses with CAD-CAM techniques.

Methods

Electronic database searches were performed using the terms “PEEK”, “CAD-CAM”, “dental”, “dentistry” to identify studies related to the use of PEEK for the fabrication of CAD-CAM prostheses. The search period spanned from January 1990 through February 2020. Both in vivo and in vitro studies in English were eligible. Review articles and the references of the included publications were searched to identify relevant articles.

Results

A great number of in vitro studies are available in the current literature pointing out the noticeable properties of PEEK. The use of PEEK has been recommended for a wide range of CAD-CAM fabricated fixed and removable dental prostheses. PEEK was additionally recommended for occlusal splints, intra-radicular posts, implant abutments, customized healing abutments and provisional restorations. However, only a few clinical studies were identified.

Conclusions

PEEK could be considered as a viable alternative for CAD-CAM fixed and removable dental prostheses to well-established dental materials. Due to the scarcity of clinical data, clinical trials are needed to assess the long-term performance of PEEK prostheses.

Clinical evaluation of performance of single unit polyetheretherketone crown restoration-a pilot study

Aim

The aim of this study was to evaluate the clinical performance and patient satisfaction of PEEK Crowns.

Setting and Design

In-vivo longitudinal pilot study.

Materials and Method

20 PEEK crowns were placed in 20 patients. 11 were placed in the maxilla and 9 were placed in the mandible. All procedural steps were performed by the same operator. The teeth were prepared with a chamfer finish line of 0.8 to 1 mm. The crowns fabricated were luted using resin cement. Using Modified Ryge's Criteria, the crowns were examined for anatomic form, marginal integrity, surface roughness, restoration staining, marginal discoloration and color match at a time interval of 1 week, 1 month, 3 months, 6 months, one year. Patient satisfaction was also evaluated at the same interval using a questionnaire.

Statistical Analysis Used

The data collected was evaluated using fisher's exact test.

Results

Based on modified Ryge's criteria, almost 90% of the crowns were rated satisfactory. Fracture was registered in only one crown. Slight chipping off was seen in two crowns. No significant difference was seen in any other factors assessed. Slight variation was seen in the periodontal status of 3 patients.

Conclusion

Within the limitations of this study the following conclusions were drawn that the PEEK crowns demonstrated by the use of Modified Ryge's Criteria, its capability to produce quality prostheses that were rated satisfactory with a relatively low rate of fracture over the relative mean period of one year.

Maxillary zirconia and mandibular composite resin-lithium disilicate-modified PEEK fixed implant-supported restorations for a completely edentulous patient with an atrophic maxilla and mandible: A clinical report

Bimaxillary implant-supported restorations for edentulous patients must include a comprehensive diagnosis, treatment plan, and careful selection of the restorative materials. The present clinical report described a completely edentulous patient rehabilitated with a zirconia framework with a facial ceramic veneer on the maxillary arch and a modified polyetheretherketone (PEEK) framework with gingival composite resin and cemented lithium disilicate crowns on the mandibular arch. The rationale for this combination of restorative materials is reviewed.