PEEK polymer's properties and its use in prosthodontics. A review.

OBJECTIVE: The aim of this study is to review polyether ether ketone (PEEK), its characteristics and use in prosthodontics. MATERIAL AND METHODS: Information search for articles about PEEK and it's use in prosthodontics between January 2010 and April 2017 was conducted in Medline via PubMed, Science direct, Wiley online library as well as the Web search Google Scholar sources. Twelve full text articles were selected and used in this review. RESULTS: 143 articles were found in the database using keywords: PEEK, prosthodontics, dentistry. Data on the suitability of PEEK polymer were organized according to mechanical, chemical, physical properties and PEEK surface preparation. CONCLUSIONS: PEEK polymer is suitable to use in prosthodontics. However, there are not enough statements about complications, biofilm formation on PEEK surface and its resistance to compression. More research should be done to find out the results.

A review of PEEK polymer's properties and its use in prosthodontics.

OBJECTIVE: The aim of this study is to review polyether ether ketone (PEEK), its characteristics and use in prosthodontics. MATERIAL AND METHODS: Information search for articles about PEEK and it's use in prosthodontics between January 2010 and April 2017 was conducted in Medline via PubMed, Science direct, Wiley online library as well as the Web search Google Scholar sources. Twelve full text articles were selected and used in this review. RESULTS: 143 articles were found in the database using keywords: PEEK, prosthodontics, dentistry. Data on the suitability of PEEK polymer were organized according to mechanical, chemical, physical properties and PEEK surface preparation. CONCLUSIONS: PEEK polymer is suitable to use in prosthodontics. However, there are not enough statements about complications, biofilm formation on PEEK surface and its resistance to compression. More research should be done to find out the results.

Evaluation of the relationship between the occlusion parameters and symptoms of the temporomandibular joint disorder.

BACKGROUND: The aetiology of temporomandibular joint disorders (TMD) is multifactorial, whereas occlusal disharmony is one of the predisposing factors. Researchers still discuss the relation between occlusion and TMD. OBJECTIVE: The study aims to investigate the relation between static occlusal parameters and TMD clinical symptoms using T-Scan II analysis system. MATERIAL AND METHODS: The sample consisted of 44 persons divided into the treatment group of 20 TMD patients and the control group of 24 subjects without TMD. The main task of T-Scan II computerized occlusal analysis system was to record every patient's occlusion and estimate static occlusal parameters: centre of occlusal force, asymmetry index of maximum occlusal force and occlusion time. These results were compared between groups, data related to patients' complaints and clinical symptoms. The analysis was carried out using Mann-Whitney U, Kruskal-Wallis and Chi-square tests. RESULTS: Averages of the centre of occlusal force in TMD subjects were 6.55 ± 0.99 mm, in the control group - 5.88 ± 0.69 mm; the asymmetry index of maximum occlusal force averages: 15.90 ± 2.71 and 12.93 ± 1.88; occlusion time: 0.281 ± 0.036 s and 0.236 ± 0.022 s, respectively. There were no statistically significant differences between two groups but they were found in the centre of occlusal force and the asymmetry index in the two groups (p < 0.05). CONCLUSIONS: There exists a relation between complaints of patients with TMD and static occlusion parameters. Values of the centre of the occlusal force distance and the asymmetry index of occlusal force in TMD patients with pain in the temporomandibular joint (TMJ) were significantly higher than in the control group.

A revised approach of human mastication function rehabilitation through monotypical mastication analysis.

OBJECTIVE: The aim of the simulation was to find the forcing laws, which provide the close-to reality mastication motions of the components of the system and to investigate the contact zones, interaction forces and their action points as they vary in time. The loss of one or few elements of the mastication system can be restored without significant violations of the overall function provided the general correlations among the mastication system elements, which were influenced during the evolutionary development, have been determined in advance. MATERIALS AND METHODS: We present an approach based on the computer simulation of mastication biomechanics on the basis of finite element (FE) models. They were generated by using the data acquired with both optical and CT scanning systems, which enabled to obtain highly accurate three-dimensional geometrical models of all hard parts of the mastication system of a real dead goat. The surfaces of dental arcs of upper and lower jaws mechanically interacting one against another have been used as the main parts of the model. RESULTS: Using FE models we discovered that mastication forces are correlated directly between dental arches and TMJ surfaces. Factors influencing geometry of dental arches results a destroy jaw function. CONCLUSION: In the course of this analysis the mastication system of a goat has been considered as a representative of the ruminant individual and enabled to demonstrate the mechanics of the mastication process with insights for evaluation of the similarities and differences against the human mastication.

New approach towards mini dental implants and small-diameter implants: an option for long-term prostheses.

BACKGROUND. Mini dental implants (MDI) and small diameter implants (SDI) have been extensively used as temporary or orthodontic anchorage; however there have been studies that proved their availability as a mean for long term prosthodontics. Our aim was to review the indications, advantages of MDI and SDI, and their long-term survival. METHODS. Computerized searches were conducted for clinical studies between year 2000 and 2011 that involved either implants with 3.3 mm diameter or less, used in prosthodontics; or provided a follow up of MDI or SDI duration of at least 4 months following implant placement including survival rate data. All studies about implants used in orthodontics were excluded. The range of available MDI and SDI has been found in cataloges of the companies: 3M ESPE IMTEC, Bicon Dental, Zimmer, Implant Direct, Intra lock, Hiossen, Simpler Implant, KAT Implants, OCO Biomedical, American Dental Implant. RESULTS. 41 studies meeting the above criteria were selected, 22 out of them reviewed survival rates of MDI and SDI. The follow up duration varried from 4 months to 8 years with survival rates between 91.17 and 100%. Nevertheless, the companies showed a big variety of MDI and SDI provided in the market for long term prostheses. CONCLUSIONS. Implants with small diameters can be used successfully in a variety of clinical situations. Less surgical time, less postoperative pain, ability of direct loading after surgery with no harm to bone and cost effectiveness are the advantages. The reduced surface implants require correct treatment planning so that the loading force would not cause bone loss or implant failure. MDI and SDI show high survival rates, but special cautions for bone quality and good oral hygiene should be maintained.