T emporomandibular disorders (TMDs) are a set of craniofacial pain-related disorders associated with impaired function in the jaw, temporomandibular joint and muscles of mastication. 1 A 2015 clinical review found that pain was most frequently reported in both the muscles of mastication and the temporomandibular joint (myalgia with arthralgia in 73% of cases), followed by myalgia alone (23% of cases). 2 Pain associated with TMD is found in 13% of the Canadian population. 3 Like other musculoskeletal disorders including chronic low back pain, fibromyalgia and headache, chronic painful TMD cannot be explained by physical conditions. The cause of TMD has changed substantially from a mechanistic origin to one that is multifactorial and biopsychosocial in nature. 1,4 Chronic TMD has been associated with somatization, anxiety, depression, parafunctional behaviours, jaw injury and other chronic pain syndromes. 1,2 Some authors have previously suggested a potential association between TMD and gastroesophageal reflux disease (GERD). 5 Gastroesophageal reflux disease is diagnosed when reflux of stomach contents precipitates troublesome symptoms. 6 Sufficient evidence supports the relation between GERD and mental disorders including somatization, anxiety and depression. 7-9 Psychological factors and somatic symptoms are closely associated with onset of TMD and persistence. 10 Mental disorders are either potential mediators connecting GERD and TMD or comorbidities caused by shared pathophysiological processes. 5 Undermined sleep mediates the effect of stress on painful TMD. 11 Considering the association between GERD and undermined sleep, 9 it is possible that undermined sleep is a mediator linking GERD with TMD. Current evidence of an association between TMD and GERD from a case-control study provides only descriptive

The high-performance thermoplastic polyetheretherketone (PEEK) has excellent mechanical properties, biocompatibility, chemical stability, and radiolucency. The present article comprehensively reviews various applications of PEEK in removable dental prostheses, including in removable partial dentures (RPDs) (frameworks and clasps), double-crown RPDs, and obturators. The clinical performance of PEEK in removable dental prostheses is shown to be satisfactory and promising based on the short-term clinical evidence and technical complications are scarce. Moreover, the accuracy of RPDs is a vital factor for their long-term success rate. PEEK in removable dental prostheses is fabricated using the conventional lost-wax technique and CAD/CAM milling, which produces a good fit. Furthermore, fused deposition modeling is considered to be one of the most practical additive techniques. PEEK in removable prostheses produced by this technique exhibits good results in terms of the framework fit. However, in light of the paucity of evidence regarding other additive techniques, these manufacturers cannot yet be endorsed. Surface roughness, bacterial retention, color stability, and wear resistance should also be considered when attempting to increase the survival rates of PEEK removable prostheses. In addition, pastes represent an effective method for PEEK polishing to obtain a reduced surface roughness, which facilitates lower bacterial retention. As compared to other composite materials, PEEK is less likely to become discolored or deteriorate due to wear abrasion.

No abstract

No abstract