Comparison to the scanning electron microscope of professional dental hygiene methods on metal-free layered structures and metal-free monolithic structures processed by different polymerization cycles

AIM

Aim of the study was to find effective instrumental methodologies and procedures for scaling and deplaquing without compromising the structure of metal-free, monolithic lithium disilicate and layered zirconia prosthetics.

METHODS

Of 14 decontaminated, extracted teeth in good anatomical condition, 7 veneers lithium disilicate monolithic and 7 layered zirconia crowns were prepared for testing and divided into 6 treatment groups. Each group was composed of a veneer and a crown. The division of the groups was carried out according to the type of treatment performed- instrumental carbon fiber and steel tips, prophylaxis paste with high and low RDA (Relative dentin abrasion), bicarbonate powder. Samples were examined and observed through a scanning electron microscope (SEM). Afterwards a detailed comparison of the images of treated and untreated samples was performed. The images were at the same magnification, thus showing the differences in the treated samples.

RESULTS

The monolithic lithium disilicate presents minor damage to the surface but no excessive changes to the structure in general post treatment. The layered zirconia resulted in notable damage with evident abrasions on the layered ceramic structure after the use of ultrasound with a steel tip and air flow with bicarbonate. Carbon fibre tips and prophylaxis paste containing perlite and low RDA did not create notable changes to the properties of the materials in question.

CONCLUSION

The results of the disilicate monolithic appear to show it to be a much more resistant material compared to layered zirconia in ceramic. Its resistance is demonstrated by the lack of notable damage in all the treatment groups.

Histological and functional changes in retrodiscal tissue following anterior articular disc displacement in the rabbit: review of the literature

AIM

Numerous studies have shown how the disc displacement, which usually occurs in an antero-medial direction, can be a factor contributing to temporomandibular joint (TMJ) pain and dysfunction. The aim of this study was to ascertain, through a critical review of the literature, current knowledge relating to anterior articular disc (ADD) in the rabbit that constitutes an extremely suitable animal model for studying the human TMJ.

METHODS

An electronic search of the MEDLINE database was performed without applying time or language restrictions and using the following key words: TMD, anterior disc displacement, rabbit, bilaminar zone. This was followed by a manual search. The articles identified were assessed to verify their pertinence, or otherwise, to the topic of investigation.

RESULTS

The articles examined were divided into the following groups according to the topic (histological and/or functional) they dealt with: experimental animal models, joint changes, elastic fibers, collagen, chondrocytes and nervous tissue.

CONCLUSION

The papers reviewed covered many aspects, both microscopic and histochemical, of the dysfunctional picture o anterior ADD, furnishing a vast body of useful information, not only from the point of view of the results recorded, but also as regards the various surgical and analytical methods used.

Role of psychosocial factors in the etiology of temporomandibular disorders: relevance of a biaxial diagnosis

AIM

The prevalence of temporomandibular disorders (TMD) is higher among women than men, indicating a multifactorial role for gender-related differences in the etiology of TMD: physiological hormonal differences, inflammatory response to stress, and sociocultural differences in response to pain. The aim of this study was to draw a biobehavioral picture of the TMD patient based on Research Diagnostic Criteria for TMD (RDC/TM) Axis II diagnosis and analysis of gender-related differences.

METHODS

Between January 2006 and January 2008, 362 subjects were consecutively enrolled from patients who presented at the Clinic for Temporomandibular Disorders, School of Dental Medicine, University of Pavia, because of orofacial pain, limitation or joint sounds on mandibular movement. Of the 362 subjects evaluated, 308 met the inclusion criteria.

RESULTS

The average age of the study population was 41 years; the female: male ratio was 4:1. When stratified according to chronic pain intensity grade and gender, 26% of the women had grade I, 36.4% grade II, 17% grade III, and 9.7% grade IV; 34.4% of the men had grade I, 32.8% grade II, 6.5% grade III, and 3.3% grade IV. Depression was moderate in 35 women and in 6 men and severe in 138 women and in 24 men; somatization was moderate in 59 women and in 20 men and severe in 143 women and in 19 men.

CONCLUSIONS

Gender-related differences may be considered risk factors for TMD; psychological characteristics, including somatization, depression, and anxiety related to gender, appear to have a significant impact on the prevalence of TMD.

Anxiety symptoms in clinically diagnosed bruxers

The present work was an attempt to investigate for the existence of an association between anxiety psychopathology and bruxism. The presence of bruxism was investigated according to validated clinical criteria in 98 subjects, who also filled out a self-report questionnaire (PAS-SR) for the assessment of panic-agoraphobic spectrum. 34.7% (n = 34) of participants were diagnosed as bruxers. The prevalence of anxiety psychopathology was similar between bruxers and non-bruxers, but Mann-Whitney U-test revealed significant differences in total PAS-SR (P = 0.026) score, indicating that subclinical symptoms of the anxiety spectrum might differentiate bruxers from controls. In particular, significant differences emerged in scores of domains evaluating panic (P = 0.039), stress sensitivity (P = 0.006) and reassurance sensitivity symptoms (P = 0.005) of panic-agoraphobic spectrum. Support to the existence of an association between bruxism and certain psychopathological symptoms has been provided.

Temporomandibular disorders and sleep disorders: which relationship?

AIM

The aim of this case-control study was to establish statistically significant associations between temporomandibular disorders (TMD) and obstructive sleep apnea (OSA) or excessive daytime sleepiness (EDS) using, respectively, the Douglass Sleep Disorders Questionnaire and the Epworth Sleepiness Scale.

METHODS

A total of 100 patients affected by TMD and 100 age- and sex-matched controls randomly chosen from the general population, answered the 2 questionnaires, which investigated their sleep habits, sleep hygiene and sleep disorders. OSA was considered as present if the total Douglass questionnaire score reached or exceeded the cut-off point of 32 for women and 36 for men. The total score on the Epworth Sleepiness Scale was calculated for each subject, a total >10 considered to indicate the presence of EDS. The data were analysed by using the chi squared test.

RESULTS

EDS was found in 19% of the patients and in 10% of the control subjects, and OSA in 6 patients and in 4 control subjects. No statistically significant association emerged between TMD and OSA. EDS was more frequent in patients with myofascial pain. On the basis of the results of the first questionnaire, we were able to develop a profile of OSA patients: they are predominantly smokers, middle-aged (40-60 years old), overweight men.

CONCLUSIONS

Although most TMD patients complain of poor sleep quality, the age and sex prevalence of OSA was lower than that of TMD, and EDS was found to be present in only a few cases.

Diagnosis of temporomandibular disorders according to RDC/TMD axis I findings, a multicenter Italian study

AIM

The aim of the present study was to evaluate the prevalence of the different Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD) Axis I types of temporomandibular disorders (TMD) in a population of subjects seeking for TMD treatment at 2 University Departments in Italy and to compare it with data from similar studies in the literature, in order to assess the usefulness of the RDC/TMD classification system as a tool for epidemiological data gathering and multicenter and cross-cultural comparison.

METHODS

A total of 210 consecutive patients seeking for TMD treatment at the Section of Prosthetic Dentistry, Department of Neuroscience, University of Pisa, Italy, and 109 consecutive patients seeking treatment at the Section of Prosthetic Dentistry and Temporo-mandibular Disorders, University of Pavia, Italy, were assessed using RDC/TMD.

RESULTS

Only 181 of the patients referring to the University of Pisa and 104 of those referring to the University of Pavia satisfied the criteria for inclusion. Findings from the 2 study populations were very similar. Mean age of the patients was 40 years, with a female:male ratio of 3.5:1 (222 females, 77.9%; 63 males, 22.1%). The prevalence of RDC/TMD Axis I diagnoses was 50.2% (143/285) for Group I disorders (muscle disorders), 38.6% (110/285) for Group II disorders (disc displacement), and 50.2% (143/285) for Group III disorders (arthralgia, osteoarthritis, osteoarthrosis).

CONCLUSION

Results from the present investigation have confirmed the usefulness of the RDC/TMD classification system for research purposes and for data gathering in cross-cultural and multicenter comparisons.

[Quality of life in patients with temporomandibular disorders]

AIM

Oral disorders have a psycho-social impact on the quality of life, that can be measured with instruments as the Oral Health Impact Profile questionnaire (OHIP). Using the OHIP, we evaluated if and how the orofacial pain can affect the quality of life in temporomandibular disorders (TMD) patients.

METHODS

A transversal case-control study was carried out. Study subjects were patients referred to the Section of Prosthetic Dentistry and Temporomandibular Disorders of the University of Pavia (Italy). Subjects were recruited sequentially until the target of 124. The controls were 61 "pain free" subjects, who were recruited from the same clinic. In analyzing the data, the chi squared test was used for categorical data, and t test and one-way analysis of variance were used for numerical scores.

RESULTS

The subjects in this study were predominantly females (83.9%). The mean age of subjects was 35.1 years (standard deviation= 14.0). The most frequently reported symptoms were pain in the temporomandibular joint (TMJ) (87.1%). The data showed that orofacial pain had an important impact on daily life (p<0.05) and that its most common outcomes were psychological.

CONCLUSIONS

Comparison with a "pain free" population clearly indicated that orofacial pain and associated symptoms negatively affect the quality of life of TMD patients.

[Pathogenesis of tension headache: role of temporomandibular disorders. A research protocol]

BACKGROUND

The purpose of this research is to verify through a blind, controlled study if there is a positive correlation between tension-type headache and the most likely causative factors. In accordance with the headache classification of the international headache society, they are: oro-mandibular dysfunction; psychosocial stress; anxiety; depression; headache as a delusion or an idea; muscular stress; drug overuse for tension-type headaches.

METHODS

The subjects who participated in the study were selected from patients diagnosed as having tension-type headache. The patients were of both sexes and aged between 18 and 60 years. A control subject was joined to every case. 102 subjects entered the study. The protocol includes the following examinations: questionnaire about the headache's characteristics; questionnaire about muscular stress; questionnaire about sleep; physiologic and pathologic history; structured Clinical Interview for DSMIII-R (Diagnostic and Statistical Manual of Mental Disorders) for diagnosis of anxiety, depression and somatoform disorder; DSMIII-R questionnaire about psychosocial stressors; EMG; algometry; evaluation of the TMJ; evaluation of the muscles of mastication; evaluation of the denture.

RESULTS AND CONCLUSIONS

A positive correlations between oro-mandibular dysfunction, anxiety, muscular stress and tension-type headache was found.