Swedish dental journal. Supplement最新文献

Background & aim: Tobacco smoking exerts a harmful effect on the periodontal tissues manifested by periodontal pockets, attachment loss and periodontal bone loss. Current evidences on the effects of tobacco on periodontal health mainly concern cigarette smoking. In view of the increasing popularity of water pipe smoking in Arabian countries and reports confirming that water pipe smoking has health effects similar to those of cigarette smoking, there is a need for a better understanding of the potential harm of this smoking habit. The present thesis was carried out in order to explore whether water pipe smoking is associated with periodontal health in a manner similar to cigarette smoking.

Material & methods: Residents in Jeddah City, Saudi Arabia, were invited to participate in the study by means of announcements in two daily newspapers. 355 individuals, 100 women and 255 men (17-60 years) responded to a standardized questionnaire and digital panoramic dental radiographs were taken. The questionnaire included information about oral hygiene practices, dental care and smoking habits. Of these subjects, 262 (73%) also volunteered for clinical examination, including assessments of oral hygiene, gingival inflammation and probing depth. Subgingival microbial test was carried out in 198 individuals for the detection of 12 different bacterial species most commonly associated with periodontal disease using the checkerboard DNA-DNA hybridization technique. Participants were stratified into water pipe smokers 33%, cigarette smokers 20%, smokers of both water pipe and cigarettes (mixed smokers 19%) and non-smokers 28%.

Results: Tobacco smoking is associated with a suppression of the gingival bleeding response to plaque accumulation. A suppressive effect was observed in both cigarette and water pipe smokers compared to non-smokers (Study I). Both cigarette and water pipe smoking were associated with the presence of more than 10 pockets of > or = 5 mm probing depth. The relative risk for periodontal disease was 5.1-fold and 3.8-fold increased in water pipe and cigarette smokers, respectively, compared to non-smokers (p < 0.01). The relative risk associated with heavy smoking was about 8-fold elevated in water pipe smokers and 5-fold elevated in cigarette smokers, suggesting an exposure-response effect (Study II). Tobacco smoking was associated with a reduction of the periodontal bone height. The reduction was of similar magnitude in water pipe smokers and cigarette smokers. The relative risk of periodontal bone loss of more than 30% of the root length was 3.5-fold and 4.3-fold elevated in water pipe and cigarette smokers, respectively, compared to non-smokers (p < 0.01). The relative risk associated with heavy smoking was 7.5-fold elevated in water pipe smokers and 6.3-fold elevated cigarette smokers (Study III). Further more, cigarette smokers, water pipe smokers and non-smokers exhibited simil

The aim of this series of studies was to investigate the relationship between skeletal bone mineral density (BMD) and mandibular alveolar bone mass (MABM), structure, and thickness, as well as to evaluate the possible effect of local functional factors on MABM and alveolar thickness. A further aim was to elucidate whether longitudinal changes in mandibular radiographic characteristics and the bucco-lingual dimension of the alveolar process were related to alterations of BMD. BMD was measured in 160 dentate women using dual X-ray absorptiometry of the forearm. On periapical radiographs MABM was estimated using densitometry and the grey-level value. The alveolar bone structure was evaluated with a visual index and by examining the bone texture on periapical radiographs. The thickness of the masseter was assessed with ultrasound imaging to estimate the masticatory functional factor, and the bucco-lingual alveolar thickness was measured on casts. MABM and alveolar structure were significantly correlated to BMD. The best correlation was found between BMD and trabecular pattern evaluated with the visual index (r = 0.62, p < 0.001). The alveolar thickness was correlated to BMD, and to masseter thickness. MABM was influenced of age, the alveolar thickness, the number of occluding teeth, and the masseter muscle thickness but these factors had no effect on the trabecular structure. After five years, all measurements except the ultrasound imaging of the masseter muscle were repeated in 136 women. The mean BMD, MABM, and alveolar thickness decreased significantly during this period, whereas no significant change was found in the bone structure. In posterior region, the alterations in alveolar bone thickness, radiographic grey-level value, and bone texture were significantly correlated to the changes in BMD. In the anterior region, the alterations in alveolar thickness were not correlated with the changes in BMD. Furthermore, no correlation was found between alterations in MABM, estimated by densitometry, and changes in BMD. In conclusion, a significant relationship exists between BMD and mandibular alveolar bone mass, structure, and thickness. The local functional factors mainly influence MABM and the alveolar thickness in the molar region, whereas BMD influences the trabecular structure. Dense trabeculation is a strong indicator of high BMD, whereas sparse trabeculation predicts low bone mass. In peri- and postmenopausal women the alveolar shape in the premolar region can be used to predict BMD level. In the lower premolar region, the longitudinal alterations in BMD are related to longitudinal changes in grey-level value, bone texture and alveolar thickness. The decrease in bucco-lingual alveolar thickness may be due to periosteal resorption related to skeletal bone loss.

Dental caries on approximal tooth surfaces in adolescents is still a problem in Sweden, as well as in many other industrialised countries. The aims of the present thesis were therefore: 1) to study whether caries prevalence is underestimated, 2) to evaluate the effect of cessation of fluoride mouth rinse (FMR) programme in schoolchildren with low caries prevalence, and 3) to reconsider the school as an arena for population-based fluoride (F) varnish and FMR programmes in order to minimise caries development in 13-16-year-olds. Paper I and II showed that the adolescents' own dentists consistently registered less caries compared to the recordings made by calibrated dentists from outside. Based on 420 16-year-olds at 12 different dental clinics in two neighbouring counties in Sweden, the differences were statistically significant at 10 of the 12 clinics when caries prevalence both was high in 1984 (Paper I) and somewhat lower in 1987 and 1990 (Paper II). About 80% of all approximal caries lesions were enamel lesions and are therefore not reported to the Swedish authorities, as only dentin lesions and fillings are currently included in the official caries data. The basis for Paper III was that many counties in Sweden abandoned school-based FMR programmes in the mid-late 1980s, as the official caries data revealed low caries prevalence among children. The cessation of FMR for 3 years for a group of 13-16-year-old adolescents (n=60) with low caries prevalence did not reveal any statistically significant differences in new caries lesions and fillings or in the progression of existing enamel lesions compared to a group of 13-16-year-olds (n=60) who continued to rinse for 3 years. Nor did a supplementary cross-sectional study reveal any differences in caries prevalence among adolescents who had or had not taken part in FMR programmes for the last 3 years. In Papers IV and V, new models for school-based F treatment were evaluated in two 3-year randomised controlled trials (RCT studies). Fluoride varnish (Duraphat) treatment, carried out at school by specially trained dental nurses using a simple mobile unit, among 854 13-16-year-olds from low, medium and high caries risk areas showed that the control groups developed more caries than the varnish groups (Paper IV). The largest difference was found in the high-risk area. The prevented fraction (PF) with approximal enamel lesions as the diagnostic threshold was 69% in high, 66% in medium and 20% in low risk areas for F varnish applied twice a year at six-month intervals. Supervised school-based FMR among 788 13-16-year-olds with low to moderate caries risk (Paper V) showed that FMR on the first three and the last three school days during the school term, i.e. 12 rinses/year, had a PF of 59%. Enamel lesions constituted > 90% of the new approximal caries lesions in both Papers IV and V. The main conclusions from this thesis are: (1) that enamel caries lesions on approximal surfaces should be included in e

In the year 2002, about 275,000 inhabitants around the world developed oral cancer and over half of them will die of their disease within 5 years. Oral and oropharyngeal squamous cell carcinoma (OOSCC) accounts for about 1% of all cancers in Sweden - which is low compared to the incidence on the Indian subcontinent and in other parts of Asia, where it is one of the most common forms of cancer. The incidence in Sweden is increasing, however. The study comprised 80% (132/165) of all consecutive cases living in the Southern Healthcare Region, born in Sweden and without previous cancer diagnosis (except skin cancer), who were diagnosed with OOSCC during the period September 2000 to January 2004. Using the Swedish Population Register, 396 cancer-free controls were identified and matched by age, gender and county. Of these individuals, 320 (81%) agreed to take part in the study. Cases and controls were subjected to a standardised interview, identical oral examinations including panoramic radiographs, and cell sampling for human papillomavirus (HPV) analysis. In total 128 patients with planned curative treatment were followed for a median time of 22 months (range 0 - 36). The aims were to assess different potential risk factors in OOSCC such as oral hygiene, dental status, oral mucosal lesions, alcohol and tobacco use, virus infection, and some related to lifestyle. A further aim was to assess the influence of these factors on recurrence or occurrence of a new second primary tumour (SPT) of squamous cell carcinoma. In multivariate analysis average oral hygiene (OR 2.0; 95% CI 1.1-3.6) and poor oral hygiene (OR 5.3; 95% CI 2.5-11.3), more than 5 defective teeth (OR 3.1; 95% CI 1.2-8.2) and more than 20 teeth missing (OR 3.4; 95% CI 1.4-8.5), as well as defective or malfunctioning complete dentures (OR 3.8; 95 % CI 1.3-11.4) were identified as significant risk factors for development of OOSCC. Regular dental care reduced the risk of OOSCC (OR 0.4; 95% CI 0.2-0.6). The cases reported a higher consumption of alcohol than the controls. More than 350 g of alcohol per week (OR 2.6; 95% CI 1.3-5.4) and 11-20 cigarettes per day (OR 2.4; 95% CI 1.3-4.1) were dose-dependent risk factors. The results showed a tendency for women to have a greater risk (OR 1.8) than men at any given level of tobacco consumption. There was no increased risk of OOSCC among users of Swedish moist snuff. There was a significant relationship between high-risk human papillomavirus (HPV) infection and OOSCC (OR 63; 95% CI 14-280). Forty-seven of the cases (36%) were high-risk HPV infected and 7 (5.3%) were low-risk HPV infected in the specimens collected from the oral cavity. The corresponding figures for the controls were 3 (0.94%) and 13 (4.1%), respectively. The high-risk HPV types found in the oral cavity were the same types as observed in cervical cancer. Tumour stage was associated with both higher relative rate (RR) of recurrence or second primary tumour (SPT) of squamous cell

The aim of the present studies was to investigate a possible relationship between the human leukocyte antigen (HLA) complex, colonization of mutans streptococci and salivary immunoglobulin A (IgA) antibodies against mutans streptococcal antigens. In the first study a strong inverse relationship between HLA-DR4 and levels of mutans streptococci was observed for a group of renal transplant patients (I). In a group with healthy blood-donors a similar trend was observed (I). This tendency was also seen for a selected population investigated in the second study (II). Since the HLA molecules regulate the production of antibodies in saliva, the salivary IgA activity to three oral streptococci in a population of HLA-DR4-positive and DR4-negative subjects was investigated in the following study (III). It was found that the HLA-DR4-positive subjects, especially the DRB1*0401 and DRB1*0404 subgroups, showed a weaker IgA activity, in particular to Streptococcus mutans, as compared to the HLA-DR4-negative. However, immune response patterns revealed by Western blotting are often complex and for further studies with larger study populations it was crucial to unravel the nature of the detected antigens. In the fourth study (IV), untreated saliva, as well as saliva, in which cell-surface reactive IgA had been absorbed with whole bacteria cells, were analysed in Western blot against different oral streptococci. The high molecular bands, that were absent after absorption, likely represented cell-surface antigens and were thus of interest as they might be involved in adhesion mechanisms and available for blocking in vivo. In the next study (V), the salivary IgA activity to cell-surface antigens of three oral streptococci in relation to different HLA-DRB1*4 alleles was studied in a larger population. The immunoblots were analysed in a computer program and intensity graphs revealed that the DRB1*0401 and *0404 subgroups, compared to other DRB1*04 types, showed fewer as well as less intense immunoblot bands to antigens from S. mutans, S. sobrinus and streptococcal antigen (SA) I/II, but not S. parasanguis. The main conclusion from this thesis is that the HLA profile of the individual seems to influence the salivary IgA response to mutans streptococcal antigens and might thus also affect the conditions for the bacteria in the oral cavity.

Introduction: Our hypothesis is that any effects on craniofacial growth and morphology induced by altering the masticatory function will vary according to the species involved. The general aim of this thesis was to test the possible effects of altering the masticatory function on craniofacial growth and morphology, as well as features of masticatory muscles in ferrets. To better elucidate these mechanisms involved, the anatomy of the skull, craniofacial growth pattern and development of occlusion in the ferret were investigated to serve as baseline data.

Materials and methods: The description of the anatomy and the radiographic features of the skull was based on observations of 100 skulls of adult ferrets of both sexes. The craniofacial growth pattern was studied in 16 young ferrets of both sexes using serial cephalograms taken on 5 occasions according to age: 25 days, 35 days, 55 days, 80 days and 300 days. To follow the development of occlusion, these animals underwent dental examinations every other day. Forty male ferrets were divided into two groups from the age of 5 weeks. One group was fed hard pellets (hard-diet group), and the other the same diet but softened with water (soft-diet group). After six months, specimens of masticatory muscles were dissected and analysed histochemically, and cephalograms were analysed cephalometrically.

Results: The ferret skull is relatively elongated with a short facial region, being longer and broader in males than in females. The viscero- and neurocranium follow an orderly pattern of expansive growth. The growth of the mandible is mainly characterized by an anteroposterior body elongation, and enlargement of the coronoid process. Craniofacial growth in ferrets ceases earlier in female than in male animals. The deciduous teeth erupted between the 19th and 31st postnatal day, and exfoliated approximately between days 51 and 76. The time of eruption of the permanent teeth ranged from 42 to 77 days. The female ferrets were generally ahead of the males regarding the eruption age of permanent teeth. The alteration of the masticatory function by feeding the animals a soft diet caused a hard palate plane more distant from the cranial base plane, smaller inter-frontal and inter-parietal widths, and a slenderer zygomatic arch, as well as a generally shorter and narrower coronoid process. Variations of most variables are greater in animals fed on soft diet. The mean cross-sectional area of type I and type II fibres in the temporalis and the masseter, and type II fibres in the digastricus, as well as the number of capillaries per fibre were significantly smaller in the soft-diet animals.

Conclusion: Altered masticatory function has induced changes in masticatory muscles and certain effects on craniofacial growth in ferrets. These changes are not the same as those reported in other species (e.g. rats). It appears that reduced mast

The miswak, a traditional chewing stick for cleaning teeth, is made from the plant Salvadora persica. For religious and cultural reasons, miswak use is firmly established and widespread in Saudi Arabia and most other Muslim countries. Only recently has scientific evaluation of the miswak been undertaken. The aims of the thesis were: 1) to explore current oral hygiene habits and oral health awareness among urban Saudi Arabians in relation to age, gender and educational level (papers I and II); 2) to compare mechanical plaque removal and gingival health after miswak use and toothbrushing (paper III); 3) to compare the effect of miswak use and toothbrushing on subgingival plaque microflora (paper IV). In papers I and II, structured interviews were conducted with 1200 regular patients at two centres in the city of Makkah, providing dental care for university and military staff and their families, respectively. Consecutive patients were stratified according to gender and age, into 6 age groups from 10 to 60 years, with 50 male or female subjects in each group at each centre. Oral hygiene habits were correlated with the subjects' age, gender, and educational levels and analysed statistically by a generalized linear model and ANOVA. In papers III and IV, the subjects comprised 15 healthy Saudi Arabian male volunteers aged 21 to 36 years, attending the Dental Center at Al-Noor Specialist Hospital in Makkah City. A single-blind, randomised crossover design was used. The Turesky modified Quigley-Hein plaque and Löe-Silness gingival indices and digital photographs of plaque distribution were recorded in Paper III and in Paper IV plaque was sampled for DNA-testing. Inhibition zones around miswak material were examined on agar plates with Actinobacillus actinomycetemcomitans and the leukotoxicity of this bacterium was analysed in a bioassay with macrophages +/- miswak extracts (paper IV). In papers I and II, 73% of the subjects used a toothbrush and 65% used a miswak daily. There were significant differences between genders and age groups, and between the centres. Regular miswak use was more prevalent among men (p < 0.01), while women used a toothbrush more often than a miswak (p < 0.05). For the majority (88%) of the individuals, oral hygiene began late, after the age of 7 yrs. Oral hygiene habits were strongly correlated to educational level (p < 0.001). The miswak was preferred by less educated people. Tooth brushing started earlier among the better educated (p < 0.001). In paper III, compared to tooth brushing, use of the miswak resulted in significant reductions in plaque (p < 0.001) and gingival (p < 0.01) indices. In paper IV, A. actinomycetemcomitans was significantly reduced by miswak use (p < 0.05) but not by tooth brushing. These results were supported by the in vitro observations that extracts from S. persica interfered with growth and leukotoxicity of A. actinomycetemcomitans. It was concluded that oral hygiene practice is introduced very l

In patients with congestive heart failure (CHF), sleep disordered breathing (SDB)--including obstructive and central sleep apnoea as well as periodic breathing--is a common condition and is believed to increase the risk of mortality. Treatment of SDB is considered important in the management of CHF. Improvements in SDB have a positive effect on cardiac output, measured with left ventricular ejection fraction (LVEF); on neurohormonal activity, measured as brain natriuretic peptide (BNP); and on the quality of life. Continuous positive airway pressure has been the traditional method used to treat SDB in patients with CHF, but compliance and tolerability are poor. A mandibular advancement device (MAD) is a dental device recommended for the treatment of sleep apnoea, but the method has never been evaluated in patients with CHF. The aims of the present studies were to evaluate the practical use of the MAD for the treatment of SDB in patients with CHF and to test the hypothesis that this intervention increases the dimensions of the pharyngeal airway (PAW), reduces SDB and BNP, and improves LVEF and the quality of life. Patients with mild to moderate CHF and SDB were evaluated using a portable polysomnographic device, lateral radiographs, cardiological and odontological examinations, and quality of life measures prior to and following intervention with an custom-made MAD. At the short-term follow-up 4-6 weeks after habituation with the MAD, the severity of SDB according to the apnoea-hypopnoea index had decreased from 25.1 +/- 9.4 (mean +/- SD) to 14.7 +/- 9.7 (p = 0.003). An increase in the inferior region of the PAW (7 +/- 5 mm) was observed on radiographs (p = 0.0001). However, no correlation between the effect of the MAD on the dimensions of the PAW and its effect on SDB was found. At the 6-month follow-up, the sleep apnoea-related symptoms had decreased by 31% (p = 0.003). Quality of life remained stable. BNP were reduced from 195.8 +/- 180.5 pg/ml to 148.1 +/- 139.9 pg/ml (p = 0.035). LVEF, however, remained unchanged. At the 12-month follow-up, 64 % of the patients were still using the MAD. Three patients withdrew from the study because of discomfort with the MAD. In most patients, MAD treatment had no severe side effect on the signs or symptoms of temporomandibular disorders. However, dental complications were observed. In conclusion, in patients with stable CHF who are experiencing problems with SDB, MAD intervention appears to reduce the severity of SDB, sleep apnoea-related symptoms, and neurohormonal activity. A lower tendency for PAW collapse may explain the effect observed on SDB. The reduction in plasma BNP may indicate decreased cardiac strain as a result of treatment of SDB. The 5-year survival rate, measured from the start of MAD intervention, was higher in the group that used a MAD than in the group that did not use a MAD (p = 0.036). No severe side effects on the stomatognathic system were observed during the intervention, and

Objectives: The general aim of this thesis was to identify and study factors that affect bonding between resin and dentin, including operator variability.

Materials and methods: Bonding sites were generated in vivo and in vitro and compared using SEM. The effects of experimental water- or acetone-based primers on shear bond strength to dentin were studied in vitro. Fourier transform infrared spectroscopy was used to establish any detrimental effects from water on polymerization by determining the degree of conversion of thin films of resin. The interaction between phosphoric acid and dentin was analyzed by measuring calcium leaching by use of atomic absorption spectroscopy. Bond strength of composite resin was measured to dentin with various degrees of demineralization. Gap formation adjacent to composite restorations in standardized dentin cavities was studied in vitro by confocal microscopy.

Results: A similar morphological appearance was found for bonding sites generated in vitro vs. in vivo. An acetone-based primer was more dependent on a moist bonding technique than was a water-based system. However, water might influence bonding by interfering with the polymerization of the resin. Calcium leaching from dentin can be predicted by use of a solubility phase diagram. No correlation could be established between calcium leaching and bond strength. Gap formation was more dependent on the operator than the choice of material. A simplified all-in-one adhesive showed less operator variability compared to more complex bonding systems.

Conclusions: In vitro bond testing may well indicate the outcome of in vivo trials. The solvents used in bonding agents will influence the performance and, presumably, technique sensitivity. Water rinse time after etching might be a more important consideration than etch time. In spite of the relative importance of the results presented above, the outcome of the multi-operator trial could not be predicted.