Olaf Bernhardt

Polymerization shrinkage-strain and microleakage in dentin-bordered cavities of chemically and light-cured restorative materials.

OBJECTIVES The aim of this study was to evaluate in vitro the relationship between polymerization shrinkage and microleakage in dentin-bordered restorations. METHODS Four light-cured restorative materials in combination with their respective dental bonding agents (DBA) were investigated: Tetric Ceram/Syntac classic (Vivadent), Solitaire/Gluma Solid bond (Heraeus Kulzer), Definite/Etch & Prime 3.0 (Degussa), Solitaire 2/Gluma Solid bond (Heraeus Kulzer). The chemically cured resin Degufill sc microhybrid (Degussa) in combination with ART Bond (Coltène) was also included. Polymerization shrinkage of the restorative materials was measured using three different methods (dilatometer, linometer, buoyancy method) and analyzed with ANOVA. For the determination of microleakage, caries-free human molars were embedded in acrylic resin and subsequently abraded with a wet abrasion machine to produce four level dentin surfaces. One hundred sixty cavities (3 mm diameter/1.5 mm deep) were randomly assigned to four groups of equal size. The groups were restored without (group 1 and 2) and with DBA (group 3 and 4), and either not subjected (group 1 and 3) or subjected (group 2 and 4) to 2000 cycles from 5-55 degrees C. Each group was further divided into five material subgroups of eight cavities each. Microleakage was determined using a dye penetration test assessed at depths of 200, 400 and 600 microm into the fillings. Data were analyzed with the Kruskal-Wallis and the Mann-Whitney test. RESULTS All three methods of measuring polymerization shrinkage (PS) generated the same, statistically secured ranking for the four light-cured restorative materials: PS Definite < PS Tetric Ceram < PS Solitaire 2 < PS Solitaire. In the microleakage study, only a few statistically significant differences were observed. Etch & Prime 3.0/Definite in group 3 and Solid Bond/Solitaire 2 in group 4 tended to exhibit the least microleakage. Correlation coefficients between aggregated shrinkage and microleakage data were 0.3 for group 3 and -0.2 for group 4. SIGNIFICANCE The results do not suggest any correlation between polymerization shrinkage and microleakage in dentin of direct adhesive restorations.

Depressive and Anxiety Symptoms as Risk Factors for Temporomandibular Joint Pain: A Prospective Cohort Study in the General Population

UNLABELLED Previous studies have associated depression and temporomandibular joint disorders (TMDs). The temporality, however, remains to be clarified. Most patient studies have selected subjects from treatment facilities, whereas in epidemiological studies a clinical examination has not been performed. In this study the 5-year follow-up data of the population-based Study of Health in Pomerania (SHIP) were analyzed. To estimate the effect of symptoms of depression and those of anxiety on the risk of TMD pain, the Composite International Diagnostic-Screener (CID-S) and a clinical functional examination with palpation of the temporomandibular joint and the masticatory muscles were used. After exclusion of subjects having joint pain at baseline, a sample of 3,006 Caucasian participants with a mean age of 49 years resulted. Of those, 122 participants had signs of TMD joint pain upon palpation. Subjects with symptoms of depression had an increased risk of TMD joint pain upon palpation (rate ratio: 2.1; 95% confidence interval: 1.5-3.0; P < .001). Anxiety symptoms were associated with joint and with muscle pain. The diagnosis, prevention, and therapy of TMD pain should also consider symptoms of depression and those of anxiety, and appropriate therapies if necessary. PERSPECTIVE Depressive and anxiety symptoms should be considered as risk factors for TMD pain. Depressive symptoms are specific for joint pain whereas anxiety symptoms are specific for muscle pain, findings that deserve detailed examination. These findings may support decision-making in treating TMD.

Association of malocclusion and functional occlusion with signs of temporomandibular disorders in adults: results of the population-based study of health in Pomerania.

The objective of this study was to determine whether associations exist between occlusal factors and signs of temporomandibular disorders (TMD) in adults using the population-based Study of Health in Pomerania (SHIP), Germany. A representative sample of 4310 men and women aged 20 to 81 years (response 68.8%) was investigated for TMD signs, malocclusions, functional occlusion factors, and sociodemographic parameters. Multiple logistic regression analysis, adjusted for sex, age, and socioeconomic status, was used. The results were compared with other population-based studies identified by a systematic review. Few malocclusions and no factors of functional occlusion except socioeconomic parameters were associated with TMD signs, and these associations were mostly weak. Only bilateral open bite up to three mm appeared to be clinically relevant and was associated with TMD signs (odds ratio [OR] = 4.0). This malocclusion, however, was of rare occurrence, with a prevalence of 0.3% (n = 9), and this finding was not confirmed by other representative studies. Occlusal factors examined in this study explained only a small part of the differences between normal subjects and those with TMD signs. This and other population-based studies indicate that malocclusions and factors of functional occlusion surveyed should be seen as merely cofactors in the sense of one piece of the mosaic in the multifactorial problem of temporomandibular dysfunction. Single occlusal factors that showed significant effects throughout several studies could not be detected. In view of the large number of occlusal variables already investigated, other variables including nonocclusal ones probably also play a role and should be looked at more intensely.

Periodontal disease, but not edentulism, is independently associated with increased plasma fibrinogen levels Results from a population-based study

The systemic response to periodontal disease was analyzed in the cross-sectional Study of Health in Pomerania (SHIP). The completed data of 2,738 subjects aged 20 to 59 years were used for logistic regression analysis with an increased plasma fibrinogen level (> or =3.25 g/L according to Clauss) as the dependent variable. Participants were divided into four groups according to the number of periodontal pockets > or =4 mm (0, 1-7, 8-14, > or =15 pocketing). An additional group comprised the 52 edentulous subjects. The adjusted odds ratio (OR) of > or =15 periodontal pockets for increased plasma fibrinogen levels was 1.88 (95% CI: 1.25-2.83). Edentulism per se was not associated with increased plasma fibrinogen levels but was contained in a two-way interaction with the number of cigarettes/day in current smokers (p = 0.031). For edentulous nonsmokers the adjusted OR was 1.10 (95% CI: 0.51-2.39). Furthermore, body mass index, the interaction between gender and body mass index, serum LDL cholesterol, medication, the interaction between LDL cholesterol and medication, aspirin, smoking, school education, chronic bronchitis, and the interaction between alcohol consumption and chronic gastritis were associated with plasma fibrinogen levels. Our results show that periodontal disease but not edentulism per se is associated with an increased plasma fibrinogen level.

Signs and symptoms of temporomandibular disorders and the incidence of tinnitus

In a cross-sectional analysis of data from the Study of Health in Pomerania (SHIP 0), temporomandibular disorders (TMD) were the strongest predictors for tinnitus beside headache. The aim of this study was to investigate whether signs and symptoms of TMD can be identified as risk factors for developing tinnitus. The SHIP 1 is a population-based 5-year longitudinal study intended to systematically describe the prevalence of and risk factors for diseases common in the population of Pomerania in northern Germany. A total of 3300 subjects (76% response) were reevaluated after 5 years for tinnitus and signs and symptoms of TMD using the same questionnaires and examination tools as baseline. To estimate the relative risk (RR) appropriately, a modified Poisson regression was used. After exclusion of prevalent cases with diagnosed tinnitus, 3134 subjects were analysed. Among the 191 exposed subjects with palpation pain in the temporomandibular joint (TMJ), 24 subjects (12·6%) received diagnosed tinnitus after 5 years, whereas among the 2643 unexposed subjects 142 subjects (5·8%) received tinnitus yielding a risk difference of 7·7% (95% confidence interval [CI]: 3·0%-12·5%) and a risk ratio of 2·60 (95% CI: 1·7-3·9). The risk ratio was 2·4 (95% CI: 1·6-3·7) after adjustment for gender, age, school education and frequent headache. Pain on palpation of the TMJ, however, did not worsen the prognosis for tinnitus in prevalent tinnitus cases (RR = 0·8, P = 0·288). Signs of TMD are a risk factor for the development of tinnitus.

Malocclusions and clinical signs or subjective symptoms of temporomandibular disorders (TMD) in adults. Results of the population-based Study of Health in Pomerania (SHIP).

Abstract.Aim and Method:The objective was to determine with reference to a representative sample of 4310 men and women aged 20 to 81 (response rate 68.8%) drawn from the population-based Study of Health in Pomerania (SHIP-0) whether associations exist between malocclusions and temporomandibular dysfunctions in adults. Besides clinically investigated signs, subjectively perceived symptoms of temporomandibular disorders (TMD) were studied in each individual together with malocclusions (plus normal occlusion), functional occlusion factors, and sociodemographic parameters. A multivariate logistic regression analysis was used, adjusted for age and discriminated for gender. The results were compared with those of other population-based studies identified by a systematic review undertaken by the present authors.Results:Some malocclusions were associated with signs or symptoms of TMD but tended to occur only rarely: unilateral open bite, negative overjet, and unilateral scissors-bite in men, and edge-to-edge bite in women. However, malocclusions (and functional occlusion factors) accounted for only a small part of the differences between the control population and the study population with signs or symptoms of TMD. In terms of the multifactorial problem of temporomandibular disorders they should be seen as cofactors. The results, together with those of other population-based studies, revealed no specific, i. e. recurring malocclusions (or other occlusal factors) presenting as risk markers.Zusammenfassung.Ziel und Methodik:Ziel war es, auf Basis der bevölkerungsrepräsentativen Study of Health in Pomerania (SHIP-0) anhand einer repräsentativen Stichprobe von 4310 Männern und Frauen im Alter von 20 bis 81 Jahren (Responserate 68,8%) festzustellen, ob Zusammenhänge bestehen zwischen Malokklusionen und temporomandibulären Dysfunktionen (TMD) bei Erwachsenen. Neben klinisch untersuchten Zeichen wurden anamnestisch erhobene, subjektiv empfundene TMD-Symptome je Studienteilnehmer untersucht sowie Malokklusionen (plus Eugnathie), Faktoren der funktionellen Okklusion und soziodemographische Parameter. Verwendet wurde die multivariate logistische Regressionsanalyse, adjustiert nach Alter und differenziert nach Geschlecht. Die Ergebnisse wurden mit anderen bevölkerungsrepräsentativen Studien eines eigenen systematischen Reviews verglichen.Ergebnis:Einige Malokklusionen waren mit TMD-Zeichen und -symptomen assoziiert, kamen jedoch nur eher selten vor: Bei Männern waren dies der einseitig offene Biss, die umgekehrte Frontzahnstufe und die einseitige bukkale Nonokklusion, bei Frauen der anteriore Kreuzbiss. Malokklusionen (und Faktoren der funktionellen Okklusion) erklärten jedoch nur einen kleinen Teil der Unterschiede zwischen der Kontrollpopulation und der Population von Fällen mit TMD-Zeichen oder -symptomen. Bezüglich des multifaktoriellen Problems der TMD sollten sie als Kofaktoren gesehen werden. Zusammen betrachtet mit anderen bevölkerungsrepräsentativen Studien stachen keine bestimmten, d. h. wiederholt auftretenden Malokklusionen (oder andere okklusalen Faktoren) als Risikomarker hervor.

Prevalence and distribution of root caries in Pomerania, North-East Germany.

The aim of this study was to assess the prevalence and distribution of root caries in the adult population of Pomerania, Germany. The study sample comprised 6,267 randomly selected subjects who were scheduled for examination from 1997 to 2001 (population-based cross-sectional study, response rate: 69%, age range 20–79 years). 499 edentulous persons were excluded from the dental examination (12%) performed according to WHO guidelines (1997). In the statistical analysis, frequency distributions, means and median values were calculated and subdivided for different age groups. The percentage of exposed and affected root surfaces increased with age (root caries index 4.6–10.6%). The mean number of carious/filled root surfaces (RDFS) rose from 0.4 per person (25–34 years) to 2.3 (55–64 years) and dropped for seniors due to the low number of retained teeth. Fillings comprised the largest proportion of the RDFS (69.5%). Most caries/fillings were found on buccal surfaces, the highest rate in mandibular premolars. With about half of over-45-year-olds having at least one carious/filled root surface and increasing number of retained teeth in seniors, root caries is a relevant and probably growing disease in Pomerania and East Germany.

Malocclusions and Clinical Signs or Subjective Symptoms of Temporomandibular Disorders (TMD) in Adults

Abstract.Aim and Method:The objective was to determine with reference to a representative sample of 4310 men and women aged 20 to 81 (response rate 68.8%) drawn from the population-based Study of Health in Pomerania (SHIP-0) whether associations exist between malocclusions and temporomandibular dysfunctions in adults. Besides clinically investigated signs, subjectively perceived symptoms of temporomandibular disorders (TMD) were studied in each individual together with malocclusions (plus normal occlusion), functional occlusion factors, and sociodemographic parameters. A multivariate logistic regression analysis was used, adjusted for age and discriminated for gender. The results were compared with those of other population-based studies identified by a systematic review undertaken by the present authors.Results:Some malocclusions were associated with signs or symptoms of TMD but tended to occur only rarely: unilateral open bite, negative overjet, and unilateral scissors-bite in men, and edge-to-edge bite in women. However, malocclusions (and functional occlusion factors) accounted for only a small part of the differences between the control population and the study population with signs or symptoms of TMD. In terms of the multifactorial problem of temporomandibular disorders they should be seen as cofactors. The results, together with those of other population-based studies, revealed no specific, i. e. recurring malocclusions (or other occlusal factors) presenting as risk markers.Zusammenfassung.Ziel und Methodik:Ziel war es, auf Basis der bevölkerungsrepräsentativen Study of Health in Pomerania (SHIP-0) anhand einer repräsentativen Stichprobe von 4310 Männern und Frauen im Alter von 20 bis 81 Jahren (Responserate 68,8%) festzustellen, ob Zusammenhänge bestehen zwischen Malokklusionen und temporomandibulären Dysfunktionen (TMD) bei Erwachsenen. Neben klinisch untersuchten Zeichen wurden anamnestisch erhobene, subjektiv empfundene TMD-Symptome je Studienteilnehmer untersucht sowie Malokklusionen (plus Eugnathie), Faktoren der funktionellen Okklusion und soziodemographische Parameter. Verwendet wurde die multivariate logistische Regressionsanalyse, adjustiert nach Alter und differenziert nach Geschlecht. Die Ergebnisse wurden mit anderen bevölkerungsrepräsentativen Studien eines eigenen systematischen Reviews verglichen.Ergebnis:Einige Malokklusionen waren mit TMD-Zeichen und -symptomen assoziiert, kamen jedoch nur eher selten vor: Bei Männern waren dies der einseitig offene Biss, die umgekehrte Frontzahnstufe und die einseitige bukkale Nonokklusion, bei Frauen der anteriore Kreuzbiss. Malokklusionen (und Faktoren der funktionellen Okklusion) erklärten jedoch nur einen kleinen Teil der Unterschiede zwischen der Kontrollpopulation und der Population von Fällen mit TMD-Zeichen oder -symptomen. Bezüglich des multifaktoriellen Problems der TMD sollten sie als Kofaktoren gesehen werden. Zusammen betrachtet mit anderen bevölkerungsrepräsentativen Studien stachen keine bestimmten, d. h. wiederholt auftretenden Malokklusionen (oder andere okklusalen Faktoren) als Risikomarker hervor.

Craniomandibular disorders — comparative investigations with clinical examination and electronic axiography

An essential problem in the diagnosis of craniomandibular disorders is still the evaluation of the type and severity of the TMJ diseases. For a differential classification of TMJ diseases, we developed an electronic axiography system which facilitates a recording of lower jaw movements. It works 3-dimensionally and relates to the joints. The measuring system, which was internationally patented, is based on a linear resistive foil for the sagittal plane and an inductive gauge for the horizontal plane. The aim of this pilot study was to evaluate the usefulness of our electronic axiography system in obtaining a differential diagnosis of craniomandibular disorders. We examined 30 patients (60 joints) with complaints in the TMJ area (pain and TMJ sounds). Clinical examinations yielded only uncertain indications of TMJ disease. With the help of electronic axiography we could differentiate the TMJ diseases into microtrauma and macrotrauma. Both forms may show a loss of function and an audible TMJ clicking. 23 joints had a macrotrauma (disk displacement with reduction, 20 times; disk displacement without reduction, 3 times). In 8 joints, a microtrauma was found. 3 joints showed a subluxation. In 4 uncertain cases, the diagnosis was confirmed with the help of magnetic resonance imaging (MRI). All patients with a diagnosed arthrogenic disorder received adequate treatment with reposition splints. Our initial results show that 3-dimensional electronic axiography can be a good aid in further characterization of craniomandibular disorders and permits an effective therapy.

Oral bony outgrowths: Prevalence and genetic factor influence. Study of twins

OBJECTIVE The aim of the study was to verify the influence of a genetic factor on the etiology of oral bony outgrowths and to determine the prevalence and type of oral bony outgrowths (tori and exostoses) among a group of Lithuanian twins. MATERIALS AND METHODS In total, 162 twins (81 twin pairs) were analyzed for the presence or absence, type, and size of oral bony outgrowths. Statistical analysis was carried out to find the prevalence of bony protuberances and the relationship between zygosity and occurrence of oral bony enlargements. Zygosity of twins was confirmed by DNA analysis. RESULTS 59.9% of the subjects had oral bony outgrowths. Mandibular tori were found in 56.8% and palatal tori in 1.8% of the sample. Palatal exostoses and mandibular exostoses were present in 1.8% and 3.1% of the sample, respectively, whereas maxillary exostoses were not found. A higher percentage of tori and exostoses were found in the group of older subjects (>18 years old, p=0.025). No significant difference was found between men and women in the prevalence of bony outgrowths. High κ and r values (0.91±0.062) showed very good concordance of oral bony outgrowths between monozygotic and moderate concordance (0.58±0.141) between dizygotic co-twins (p<0.001). The calculation of heritability estimate verifies dominant influence of genetic factor on the etiology of oral bony outgrowths (h(2)=0.658). CONCLUSION The most common bony outgrowth was torus mandibularis. Our results show that the genetic factor is dominant in the etiology of oral bony outgrowths.