Xerostomia in 75-85-year-olds: A longitudinal population study.

BACKGROUND: Xerostomia can pose significant problems for many elderly people. OBJECTIVES: To investigate longitudinal changes in prevalence, persistence, progression, remission and incidence of xerostomia from age 75 to 85 years. METHODS: All 75-year-olds (born 1932) from two Swedish counties, Sweden were mailed a questionnaire in 2007 (N = 5195), and again in 2017 when they were aged 85 (N = 3323). The total response rates at ages 75 and 85 years were 71.9% and 60.8%, respectively. A 'panel', those who participated in both surveys, comprised 1701 individuals (response rate 51.2%). RESULTS: At age 85, there was almost a doubling of self-reported 'yes often' xerostomia compared with age 75 (from 6.2% to 11.3%) and was almost twice as common in women than men (p < .001). When combining 'yes often'/'yes sometimes', xerostomia increased from 33.4% to 49.0%, and was more so among women (p < .001). Xerostomia was commoner at night than daytime, with 23.4% reporting 'yes often' night-time xerostomia at 85 compared with 18.5% at 75, and was also higher in women (p < .001). Progression rates for daytime and night-time xerostomia were 34.2% and 38.1%, for persistence 67.4% and 68.6%, and for remission 24.4% and 16.5%. Average yearly incidence was higher in women than men for both daytime (3.6% vs. 3.2%) and night-time (3.9% vs. 3.7%). Regression analyses predicted protective factors for developing xerostomia reported at age 75 as good general and oral health, absence of medications/intraoral symptom/s, good chewing function and social interaction. CONCLUSIONS: Xerostomia increases markedly from age 75 to 85 years.

Satisfaction with dental appearance in two cohorts of 75-year-olds examined in 2007 and 2017: A repeated cross-sectional study.

BACKGROUND: Satisfaction with dental appearance plays an important role in the self-esteem and psychological well-being of the elderly, the significance of which the attending dentist may not always be fully cognisant of. OBJECTIVES: To assess the level of satisfaction with dental appearance, its associated factors and temporal changes in two cohorts of 75-year-old Swedes born 10 years apart. METHODS: In 2007, a questionnaire was mailed to all those living in Örebro and Östergötland counties, Sweden, who were born in 1932 (n = 5195), and in 2017 to all born in 1942 (n = 7204). The evaluation was carried out with a global question 'Are you satisfied with the appearance of your teeth?', and four attitude-related statements about dental appearance. RESULTS: About 80% in both cohorts were 'very satisfied' or 'to large extent satisfied' with their dental appearance. The 1932 cohort was significantly more concerned about their dental appearance than the 1942 cohort, and women were generally also significantly more concerned than men. In the regression analysis, 'very satisfied' with dental appearance was predicted by good chewing efficiency, having complete dentures, no impact from Oral Impacts on Daily Performance, disagreement that 'minor esthetic imperfections of the teeth have no importance, only they should function well', better perceived general health than same-aged peers and belonging to the 1932 cohort. CONCLUSION: Satisfaction with dental appearance among 75-year-olds was generally high, with attitudes varying by gender and temporally. Women and the earlier-born generation (1932) were more concerned about dental appearance than men and the later-born generation (1942), respectively.

Changes in conditions related to reported oral and general health over a ten-year period as reflected in two cohorts of 75-year-old subjects examined in 2007 and 2017.

BACKGROUND: The rapidly ageing and increasingly dentate population puts great demands on society regarding the provision of adequate medical and dental care facilities. OBJECTIVES: To present changes in reported demographic, general and oral health factors in two cohorts of 75 year olds in 2007 and 2017, and to analyse factors associated with self-reported number of remaining teeth and chewing efficiency. MATERIAL AND METHODS: All 75-year-old people living in two Swedish counties received a questionnaire in 2007 and in 2017. The response rates in 2007 and in 2017 were 71.9% (n = 3735) and 70.7% (n = 5091), respectively. Reported number of teeth was clinically validated in a selected subgroup. RESULTS: The 2017 cohort reported significantly better general health and dental state. Edentulousness was 7.8% in 2007 and 2.3% in 2017, while 'very good' chewing efficiency was 55.2% and 60.5%, respectively. Born outside Sweden, single living, not feeling healthy and smoking predicted reduced number of teeth in both cohorts. Impaired chewing efficiency in both cohorts was predicted by being born outside Sweden, lower education, not feeling healthy, reduced number of teeth and denture wearing. CONCLUSIONS: Seventy-five-year-old people in Sweden reported much better oral and general health in 2017 compared to 2007. In 2017, 75% had practically all natural teeth present and only 2% were edentulous. This development of an increasingly dentate and partially dentate ageing population will put high demands on the oral healthcare system and will need adapting undergraduate/postgraduate education and management strategies to meet the requirements of the elderly.

Self-reported dry mouth in 50- to 80-year-old Swedes: Longitudinal and cross-sectional population studies.

Xerostomia is a common condition among elderly. The objectives were to examine prevalence, persistence, progression, yearly incidence of xerostomia, associated background factors and its influence on oral impacts on daily performances (OIDP) in 50- to 80-year-old people. In 1992, a questionnaire was sent to all 50-year-old (n = 8888) and in 2007 to all 75-year-old persons (n = 5195) living in two Swedish counties. In 2012, the same questionnaire was sent to both age cohorts, now 70- and 80-year-old. Response rate was for the 50-, 70- 75- and 80-year-old groups 71.4%, 72.2%, 71.9% and 66.4%, respectively. In the 50- to 70-year-old sample, 40.3% of the participants answered all five examinations and in the 75-80 group 49.5% (intact samples). In all age groups, xerostomia was significantly more prevalent in women than in men. At age 80, "often mouth dryness at night" was reported by 24.3% and 16.2% of women and men, respectively. Prevalence increased with age and was more frequent at night-time. Persistence of xerostomia was reported by 61.4%-77.5%, progression by 11.5%-33.0% and remission by 5.7%-11.3%. Average yearly incidence was 0.99%-3.28%. Xerostomia was more prevalent in those who reported a negative impact on OIDP. Highest odd ratios for xerostomia were burning mouth (OR 12.0), not feeling healthy (OR 5.1) and medicine usage (OR 3.9). Xerostomia is common in older age, persistence is high and progression common. The comorbidity between xerostomia, oral health problems and impaired general health needs to be taken into consideration when providing dental care to elderly patients.

An International Survey among Prosthodontists of the Use of Mandibular Implant-Supported Dental Prostheses.

PURPOSE: To evaluate the use of implant-supported overdentures (IOD) and implant-supported fixed dental prostheses (IFDP) in patients with edentulous mandibles among international prosthodontists. MATERIALS AND METHODS: A questionnaire was sent by e-mail to all clinically active prosthodontists in the International College of Prosthodontists with questions related to implant treatment of the edentulous mandible performed in 2015. RESULTS: One hundred and sixteen prosthodontists from 33 countries responded to the questionnaire. The vast majority of the responding prosthodontists was faculty or worked in private practice, and the great majority had performed treatment with mandibular implant-supported dental prostheses; however, two thirds of the respondents reported that <20% of the implant patients in their clinic had received treatment related to edentulous mandibles. The majority reported using 2 implants (84%), while 13% used 4 for overdenture retention. There were great variations regarding retention systems used for mandibular IODs; the most common was individual Locator attachments. Cost was considered the most common reason to choose mandibular IOD, There was a wide variation of materials used for mandibular IFDPs. The most common combination included milled titanium frameworks and acrylic resin teeth. CONCLUSIONS: This survey, completed by 116 prosthodontists from 33 countries, showed that implant treatment for edentulous mandibles is common, but there was great variation among the respondents regarding amount of treatments performed, design, and materials used for the implant prostheses.

Zirconia abutments for single-tooth implant restorations: a 10- to 11-year follow-up study.

OBJECTIVES: To evaluate the clinical outcome of custom-made zirconia abutments for implant-supported single-tooth restorations 10-11 years after insertion. MATERIAL AND METHODS: The study comprises a clinical examination of 23 patients with 30 restorations placed 10-11 years ago. Oral surgeons placed the implants. The prosthodontic treatment was provided at a prosthodontic specialist clinic. The restoration was either an all-ceramic crown for cementation or a screw-retained one-piece restoration with the veneering porcelain baked directly to the zirconia abutment. Besides the clinical and radiographic examination at the 10- to 11-year follow-up, the patients' records were scrutinized regarding clinical and radiographic data from insertion of the restoration up to the last visit at the clinic. RESULTS: The zirconia abutments performed well. Both technical and biological complications were rare; most patients were in general extremely satisfied with the restorations. No all-ceramic crowns fractured during the observation period. One implant was lost after 5½ years in service. There were no significant differences for changes in any of the soft tissue registrations or the peri-implant marginal bone level between the conventional two-piece abutment-crown restoration and the one-piece restoration. The peri-implant bone level changes from placement to the clinical examination 10-11 years later were small (mean 0.26 mm, SD 0.6 mm). CONCLUSIONS: Zirconia abutments for single-implant crowns demonstrated excellent technical and biological results over 10-11 years of function, and most patients were extremely satisfied with the aesthetics and the function of their single-implant restorations.

Some issues related to evidence-based implantology.

This article reviews relevant dental literature to answer some frequent questions related to evidence-based implantology. There are hundreds of implant systems on the market, but the majority lack clinical documentation. Recommended number of implants for full-arch fixed prostheses is four or five in the mandible but at least six in the maxilla. Less expensive implant-retained overdentures make implant treatment available to a greater portion of edentulous subjects. Mandibular overdentures on two implants, and even one implant, have shown excellent long-term outcomes. In the maxilla, less than four implants are not recommended for good results. Single implant restorations have good prognosis, but placement of the implant should be postponed until adulthood. Osseointegrated implants have revolutionized clinical dentistry. However, in a global perspective, implants make up only a small part of all prosthodontic treatment. Knowledge and skill in conventional prosthodontics must be maintained as it will remain the most common part of the specialty.

Is there a trend of decreasing prevalence of TMD-related symptoms with ageing among the elderly?

OBJECTIVE: Older adults have not been studied as much as younger ones regarding prevalence of TMD-related symptoms. The aim was to assess the prevalence of TMD-related symptoms in two population samples, 70 and 80 years old. MATERIALS AND METHODS: Identical questionnaires were in 2012 sent to all subjects born in 1932 and 1942 living in two Swedish counties. The response rate was 70.1%, resulting in samples of 5697 70- and 2922 80-year-old subjects. The questionnaire comprised 53 questions. Answers to questions on problems regarding TMD-related symptoms and awareness of bruxism were analysed. RESULTS: Twelve per cent of the women and 7% of the men in the 70-year-old group reported some, rather great or severe problems regarding TMD pain. In the 80-year-olds the prevalence was 8% and 7%, respectively. Subjects who had problems with TMJ sounds reported difficulty to open the jaw wide 6-times and TMJ pain 10-13-times more frequently than subjects without such problems. Changes of taste and awareness of bruxism were the only variables significantly associated with TMD symptoms in both age groups. Number of teeth was not significantly associated with any of the TMD-related symptoms. CONCLUSIONS: Most of the elderly subjects had no severe problems with TMD-related symptoms, but 12% of the 70-year-old women reported some, rather great or severe problems. The marked gender difference at age 70 had disappeared in the 80-year-old group. The prevalence was lower among the 80- compared with the 70-year-old subjects of both sexes. The results support the comorbidity between TMD-related symptoms and general health problems.

Use of implant-supported prostheses in edentulous mandibles among prosthodontists in Sweden.

The aim of this study was to investigate the production of mandibular implant-supported fixed and removable prostheses among prosthodontic specialists in Sweden and to compare the results with findings in a similar study made in 2001 (17). Questionnaires regarding treatment with mandibular implant prostheses during 20011 were mailed to all specialists in prosthodontics in Sweden (n = 156, according to available data). Of the 156 questionnaires, 129 (83%) were returned and of those 114 were completed. The reported number of treatments with mandibular implant-supported prostheses varied much among the specialists. Fixed implant prostheses were more common than overdentures (means 11 and 3, median values 8 and 2, respectively). However, the range was large for both alternatives. Ten (9%) of the specialists reported no treatment with fixed implant prostheses while 29 (25%) had not made any implant overdenture during 2011. The most common anchorage system for overdentures in 2011 (as well as in 2001) was two un-splinted implants with ball attachments or Locator abutments. The most common reasons for choosing overdenture treatment instead of a fixed implant prosthesis in 2011 were the reduced cost and the patient's main wish to improve denture retention. A majority of the prosthodontists (58%) reported that patients with implant overdentures were as satisfied as those with fixed implant-supported prostheses, whereas 40% claimed they were less satisfied. Two respondents (2%) considered that overdenture patients were more satisfied than those with a fixed prosthesis. It can be concluded that the general attitude among Swedish prosthodontists towards implant overdentures has not changed much during the 10-year period between the present and the previous investigation.An overdenture is still a seldom-used option in implant treatment of patients with edentulous mandibles in Sweden. Instead, a fixed implant-supported prosthesis continues to be the preferred option,

Building Markov state models with solvent dynamics.

BACKGROUND: Markov state models have been widely used to study conformational changes of biological macromolecules. These models are built from short timescale simulations and then propagated to extract long timescale dynamics. However, the solvent information in molecular simulations are often ignored in current methods, because of the large number of solvent molecules in a system and the indistinguishability of solvent molecules upon their exchange. METHODS: We present a solvent signature that compactly summarizes the solvent distribution in the high-dimensional data, and then define a distance metric between different configurations using this signature. We next incorporate the solvent information into the construction of Markov state models and present a fast geometric clustering algorithm which combines both the solute-based and solvent-based distances. RESULTS: We have tested our method on several different molecular dynamical systems, including alanine dipeptide, carbon nanotube, and benzene rings. With the new solvent-based signatures, we are able to identify different solvent distributions near the solute. Furthermore, when the solute has a concave shape, we can also capture the water number inside the solute structure. Finally we have compared the performances of different Markov state models. The experiment results show that our approach improves the existing methods both in the computational running time and the metastability. CONCLUSIONS: In this paper we have initiated an study to build Markov state models for molecular dynamical systems with solvent degrees of freedom. The methods we described should also be broadly applicable to a wide range of biomolecular simulation analyses.

Management of tinnitus and jaw-muscle tenderness using an intraoral appliance and acupuncture.

Associations between signs and symptoms from the masticatory system and tinnitus have been reported.The aim of the study was to evaluate the effect of intraoral splint therapy and acupuncture on jaw-muscle tenderness and tinnitus. The study comprised 45 patients (24 men, 21 women; mean age 48 +/- 12 years) with long-standing tinnitus (duration 6.5 +/- 5.9 years).The patients were referred from the audiology department at the University hospital in Orebro, Sweden, where a complete audiological survey was performed. Jaw muscles were palpated and the subjective tinnitus evaluated on a 100 mm scale (VAS) at baseline and after one year. All patients received stabilization (Michigan type) splints at start of treatment. After 6 months, nonresponders (n=25) were subjected to acupuncture (6 sessions with duration of 30 minutes). Standard statistical methods were used. All patients had tender jaw muscles at palpation. Patients reported a significant decrease of the intensity of tinnitus during the observation period (from 78 +/- 20 mm to 52 +/- 24 mm after one year; P < 0.001). Only 6 (13%) of the 45 patients did not report any improvement of their tinnitus.The number of jaw muscles tender to palpation also decreased significantly from 7.9 +/- 5.9 to 4.6 +/- 5.3; (P<0.001). In conclusion, all 45 patients with tinnitus had tenderjaw muscles. Intraoral splint therapy and acupuncture had a favorable effect on tinnitus and the jaw muscle symptoms. One year after the start of treatment, all but 6 of the 45 patients reported improvement of their tinnitus. Based on the results it is suggested that many tinnitus patients with jaw muscle tenderness can benefit by a treatment including intraoral splint and acupuncture.

Topological data analysis in medical imaging: current state of the art.

Machine learning, and especially deep learning, is rapidly gaining acceptance and clinical usage in a wide range of image analysis applications and is regarded as providing high performance in detecting anatomical structures and identification and classification of patterns of disease in medical images. However, there are many roadblocks to the widespread implementation of machine learning in clinical image analysis, including differences in data capture leading to different measurements, high dimensionality of imaging and other medical data, and the black-box nature of machine learning, with a lack of insight into relevant features. Techniques such as radiomics have been used in traditional machine learning approaches to model the mathematical relationships between adjacent pixels in an image and provide an explainable framework for clinicians and researchers. Newer paradigms, such as topological data analysis (TDA), have recently been adopted to design and develop innovative image analysis schemes that go beyond the abilities of pixel-to-pixel comparisons. TDA can automatically construct filtrations of topological shapes of image texture through a technique known as persistent homology (PH); these features can then be fed into machine learning models that provide explainable outputs and can distinguish different image classes in a computationally more efficient way, when compared to other currently used methods. The aim of this review is to introduce PH and its variants and to review TDA's recent successes in medical imaging studies.

Prevalence of troublesome symptoms related to temporomandibular disorders and awareness of bruxism in 65- and 75-year-old subjects.

OBJECTIVE: To assess the prevalence of three troublesome temporomandibular disorder (TMD) symptoms and awareness of bruxism in two cohorts of subjects aged 65 and 75 years. BACKGROUND: Epidemiological studies have demonstrated varying prevalence of TMD symptoms. The results concerning elderly people are inconclusive. MATERIAL AND METHODS: In 2007 identical questionnaires were sent to all subjects born in 1942 and 1932 living in two Swedish counties. The response rate was 73.1% for the 65- and 71.9% for the 75-year-old subjects, totally 9093 subjects. RESULTS: The great majority reported no or only a few TMD problems. Less than 4% considered their TMD symptoms to be rather great or severe. The mean prevalence of TMD-related symptoms and bruxism was greater in women than in men in both age groups. The 75-year-old women reported a marked lower prevalence of TMD symptoms and bruxism than the 65-year-old women, whereas the age differences were small among the men. Self-reported bruxism was associated with a higher prevalence of TMD symptoms. CONCLUSIONS: The great majority of the subjects did not report any troublesome TMD related symptoms. However, 5.4% of the 65-year-old women and 3.8% of the 75-year-old women considered their symptoms severe or rather severe.

Self-reported dry mouth in Swedish population samples aged 50, 65 and 75 years.

BACKGROUND: Reduced salivary flow may have a negative impact on general well-being, quality of life and oral health. OBJECTIVES: To examine xerostomia in 50-, 65- and 75-year-olds, background factors and effect on Oral Impacts on Daily Performances (OIDP). METHODS: In 1992, a questionnaire was sent to all 50-year-old persons (n = 8888) in two Swedish counties. In 2007, the same questionnaire was sent to all 65-year-olds (n = 8313) in the two counties and to all 75-year-olds (n = 5195). Response rate was for the 50, 65 and 75 year olds 71.4, 73.1 and 71.9%, respectively. RESULTS: Xerostomia was higher in women than in men in all age groups. There was higher prevalence of xerostomia with increasing age in both sexes and it was more frequent at night than during daytime. 'Often mouth dryness' was 2.6-3.4 times more prevalent in those who reported an impact from OIDP. The highest odd ratios were for daytime xerostomia and for the variables burning mouth (17.1), not feeling healthy (4.5), daily smoking (4.4), and medication (4.1). CONCLUSIONS: The dramatic increase of xerostomia between age 50 and 75, especially amongst women, needs to be considered in the management of this age group.

Prediction of xerostomia in a 75-year-old population: A 25-year longitudinal study.

OBJECTIVES: To follow the same individuals from age 50 up to 75 years to report on prevalence, persistence, progression, remission, incidence and predictors for xerostomia. METHODS: A questionnaire was distributed to all 50-years-olds (1992) in two Swedish counties (N = 8888) and repeated at the age of 65 (2007) and 75 years (2017). 3060 individuals responded on all three occasions (response rate 42.5%). Xerostomia was assessed with two questions. Additional questions addressed inter alia general/oral health and oral function. RESULTS: Reported prevalence of daytime xerostomia were 23.3% and 14.7%, and 39.5% and 27.5% in women and men, age 50 and 75, respectively. Night-time prevalence was higher. At age 50, 27.4% women and 24.0% men reported having dry mouth, and at age 75, 61.0% and 53.8%, respectively. At all time points, women reported significantly more xerostomia than men. Progression (deterioration) was common, and persistence (continuing presence) was high, while 25-year incidence for daytime xerostomia was 16.2% and 12.8%, and 33.6% and 29.8% at night-time, for women and men, respectively. Based on reports at age 50, regression analyses showed that prediction for developing xerostomia during the observation period, and reporting xerostomia at age 75 years, were female gender, impaired general health, chewing, jaw opening and intraoral problems, dissatisfaction with dental appearance, low education and having white/plastic filling. CONCLUSIONS: Xerostomia is common in older people, especially at night and in women. It can be predicted by diverse factors reported earlier in life. CLINICAL SIGNIFICANCE: Clinicians need to be made aware of that elderly often suffers from dry mouth so that they can recommend effective measures to eliminate or ease the patients accompanying symptoms and also exclude or lessen possible negative impact on oral health related to xerostomia.

Temporal changes and gender differences related to orofacial symptoms in two cohorts of 75-year-old Swedish subjects examined in 2007 and 2017: A repeated cross-sectional study.

OBJECTIVES: To compare two cohorts of 75-year-old persons, born 10 years apart, in regard to reported symptoms related to temporomandibular disorders (TMD) and orofacial complaints with special reference to gender differences. MATERIAL AND METHODS: In 2007, a questionnaire comprising questions on social factors, general and oral health, and a series of attitude-related questions was mailed to all individuals born in 1932 living in two Swedish counties (N = 5195), and in 2017 to all born in 1942 (N = 7204). The response rate for the cohort examined in 2007 was 71.9% (n = 3735) and 70.7% (n = 5091) for the cohort examined in 2017. Bivariate statistical analyses were applied. RESULTS: Reported bruxism and pain from the temporomandibular joint were significantly higher in the 1942 cohort compared to the 1932 cohort, while reports of oral lesions and daytime dry mouth were lower. Women reported problems significantly more frequently in most of the domains investigated in both 2007 and 2017, that is, TMD, burning mouth, sensitive teeth, oral lesions, taste changes, daytime/night-time dry mouth, except bad breath. CONCLUSIONS: TMD-related symptoms increased while complaints from oral lesions and daytime mouth dryness decreased between 2007 and 2017. Temporal changes were otherwise few, but the findings underline the gender inequalities that exist, to the disadvantage of women. This must be considered when planning for clinical care/dental education to appropriately address the needs of older people.

Comparative study of left atrium epicardial fat tissue pattern using persistent homology approach.

OBJECTIVE: Atrial Fibrillation (A-fib) is an abnormal heartbeat condition in which the heart races and beats in an uncontrollable way. It is observed that the presence of increased epicardial fat/fatty tissue in the atrium can lead to A-fib. Persistent homology using topological features can be used to recapitulate enormous amounts of spatially complicated medical data into a visual code to identify a specific pattern of epicardial fat tissue with non-fat tissue. Our aim is to evaluate the topological pattern of left atrium epicardial fat tissue with non-fat tissue. RESULTS: A topological data analysis approach was acquired to study the imaging pattern between the left atrium epicardial fat tissue and non-fat tissue patches. The patches of eight patients from CT images of the left atrium heart were used and categorized into "left atrium epicardial fat tissue" and "non-fat tissue" groups. The features that distinguish the "epicardial fat tissue" and "non-fat tissue" groups are extracted using persistent homology (PH). Our result reveals that our proposed research can discriminate between left atrium epicardial fat tissue and non-fat tissue. Specifically, the range of Betti numbers in the epicardial tissue is smaller (0-30) than the non-fat tissue (0-100), indicating that non-fat tissue has good topology.

Zirconia abutments for single-tooth implant restorations: a retrospective and clinical follow-up study.

OBJECTIVE: To evaluate the clinical outcome of custom-made zirconia abutments for implant-supported single-tooth restorations up to 5 years after insertion. MATERIAL AND METHODS: The study comprises two parts: (Part 1) retrospective evaluation of records of 130 patients treated with 185 single-tooth implant restorations using zirconia abutments; (Part 2) clinical examination of 25 patients with 40 restorations placed >3 years ago. Oral surgeons placed the implants. The prosthodontic treatment was provided at a prosthodontic specialist clinic. The restoration was either an all-ceramic crown for cementation or a screw-retained one-piece restoration with the veneering porcelain baked directly to the zirconia abutment. Registration of all patients' records comprised clinical and radiographic data from insertion of the restoration up to the last visit at the clinic. RESULTS: Parts 1 and 2: The zirconia abutments performed well over the follow-up period. The rates of both technical and biological complications were low, and the patients were in general extremely satisfied with the restorations. No all-ceramic crowns fractured during the observation period. Two abutments (1%) fractured, one at insertion, the other after 2 months. Part 2: There were no significant differences for changes in any of the soft tissue registrations or the peri-implant marginal bone level between the conventional two-piece abutment-crown restoration and the one-piece restoration. The peri-implant bone level changes from placement to the clinical examination 3-5 years later were small (mean 0.29 mm, SD 0.87 mm). CONCLUSION: Zirconia abutments for single-implant crowns seem to demonstrate good short-term technical and biological results.

Some dogmas related to prosthodontics, temporomandibular disorders and occlusion.

It is the aim of this paper to give a few examples of dogmas related to prosthodontics and oral implants and to discuss the controversial role of occlusion in the aetiology of temporomandibular disorders. New knowledge is developing at a rapidly increasing rate in dentistry, as in other areas of society. Our lecturers at university taught us many useful things. But, as time goes by, what is still relevant? Some methods are so well established that they deserve to be called dogmas. It is implied that a dogma is not supported by strong evidence, even though it has existed and been practised for a long time. In the era of evidence-based dentistry it is appropriate to scrutinize such issues. A review of the current literature indicates that conflicting opinions exist concerning a number of common procedures in clinical dentistry, mainly due to a scarcity of good studies with unambiguous results. There is therefore a need for more high-quality clinical research in attempting to reach the goal of evidence-based clinical practice. The dental community should take an active part in this process.

Temporomandibular disorders and oral health-related quality of life. A systematic review.

OBJECTIVE: Oral health-related quality of life (OHRQoL) is considered an important aspect of different oral conditions. It has also gained increased attention in temporomandibular disorders (TMDs) in recent years. The purpose of this study was to systematically review the literature on OHRQoL and TMDs. MATERIAL AND METHODS: A systematic search of the dental literature was performed using the Medline and Cochrane Library databases, supplemented by a hand search. Various combinations of search terms related to OHRQoL and TMDs were used. Among numerous titles found in Medline, abstracts and eventually full papers of potential interest were reviewed. Twelve papers fulfilled the inclusion criteria and were included in the review. RESULTS: Most studies used the Oral Health Impact Profile, an instrument with good psychometric properties, for evaluation. All articles described a substantial impact on OHRQoL in TMD patients. Only a small proportion of all patients, a few percent, reported no impact at all. The difference between men and women was small and not significant. The impact appeared to be more pronounced in patients with more signs and symptoms. The perceived impact of pain on OHRQoL seems to be substantial. Two studies found that the impact increased with age among TMD patients. CONCLUSIONS: The reviewed studies convincingly demonstrated that OHRQoL was negatively affected among TMD patients.