Swedish dental journal. Supplement最新文献

Unlabelled: The main aim of this thesis was to study the oral health and the self-perceived oral treatment need of adults in Sweden. The first step was to analyse the self-perceived oral treatment need in a random national sample of young adults (20 to 25-year-olds). This study used one patient and one dentist questionnaire. The patient questionnaire was sent to 611 young adults and the response rate was 78%. After permission from 377 of these individuals, a questionnaire was sent to their dentists and answers were received from 85% (321 dentists). How the individuals perceived their oral treatment need was used as a dependent variable in a multivariate logistic regression model. Independent variables were self-assessed socio-economic situation, general health and dental attitudes together with information from the dentists on their patient's dental status. The results showed that having a high educational level, poorer oral health compared to one's peers, and being concerned about one's oral health significantly increased the odds for a high perceived oral treatment need. In this group of young adults, 33% perceived a high oral treatment need. In order to study if the oral treatment need was the same in all adult age groups and how the perceived oral health was in an adult Swedish population, a new questionnaire was sent to a random sample of 9 690 individuals, 20 to 89-year-olds, living in Skåne, Sweden. The response rate was 63%. The results showed that a majority of the adult population in Skåne had a positive perception of their oral health, in particular the individuals in the youngest age group. Most individuals had lost few teeth and removable dentures were uncommon. One third rated their dental treatment need as high. The highest proportion of individuals with a perceived high oral treatment need was found in the age group 70-79. In order to study the perceived oral treatment need in all adult age groups, the questionnaire was further analysed. The Andersen behavioural model was used as a theoretical framework for a multivariate logistic regression model. Questions that fit the components of individual characteristics, health behaviour and outcomes in the model were used as independent variables. The self-perceived oral treatment need was used as a dependent variable. The results showed that the Andersen behavioural model was found to be a useful tool when studying the perceived oral treatment need, and variables from all of the components in the model were significant. Important factors for the prediction of a high oral treatment need were a low educational level, previous unmet perceived oral treatment need, frequent visiting pattern, perception of worse oral health, external locus of control, and to have received information from one's dental caregiver about a need for oral treatment. The evaluated oral health was also studied using another sample of adults from the same region and of the same age. 966 individuals

Preterm birth is associated with medical complications and treatments postnatally and disturbances in growth and development. Primary and permanent teeth develop during this postnatal period. The overall aim of the present thesis was to elucidate the effects of preterm birth and postnatal complications on oral health and the dentoalveolar development during adolescence, and to study the effects of preterm birth on caries during childhood, in a well-defined group of preterm infants. In the same group, explore the development of the primary and permanent teeth and compare the results with a matched control group and control teeth. The subjects consisted of 40 (45) of 56 surviving infants, born < 29 weeks of gestational age (GA), and matched healthy children born at term. The material consisted of 44 teeth from 14 of the preterm adolescents and 36 control teeth from healthy children. Clinical examinations and dental cast analysis were performed during adolescence and morbidity was noted. Retrospective information from medical and dental records was obtained. Dental enamel was analyzed in a polarized light microscopy, and scanning electron microscopy. Further, chemical analyses of enamel and dentin were performed with X-ray microanalysis. The results showed that during adolescence, more preterms had plaque and gingival inflammation, lower salivary secretion, more S. mutans and severe hypomineralization. Retrospectively, less caries was noted at six years of age, but more children had hypomineralization in the primary dentition. Angle Class II malocclusion, large over-bite and deep bite associated with medical diagnoses were frequent. Furthermore, smaller dental arch perimeters in girls, at 16 years of age, and smaller tooth size in the incisors, canines and first molars were found. The morphological findings were confirmed in the XRMA analyses. In postnatal enamel, varying degrees of porosities > 5% and incremental lines were seen. Lower values of Ca and Ca/C ratio and higher values of C were found. Ca/P ratio in both enamel and dentine indicates normal hydroxyapatite in both groups. No single medical diagnosis, postnatal treatment or morbidity in adolescents could explain the findings. As a conclusion, there are indications for poor oral outcome in this group of preterm infants during adolescence, and disturbed mineralization in primary teeth.

Unlabelled: OVERALL AIM: The general objective of this thesis was to enhance the understanding of Molar Incisor Hypomineralization (MIH) in areas of the histological, chemical and mechanical properties of the hypomineralized enamel, objective and subjective clinical symptoms in relation to bacteria findings. Further, to estimate a time for onset of the disturbance and investigate possible etiological factors.

Material & methods: 22 teeth diagnosed with MIH were used in the histological and chemical studies. A number of analytical methods were used; Light microscopy, Polarized light microscopy, Scanning electron microscopy, X-ray microanalysis, Vickers hardness test and X-ray Micro Computed Tomography. Decalcified sections were stained with bacterial staining. An ozone device was tested for the ability to kill strains of oral bacteria. In collaboration with the prospective ABIS study, 17.000 individuals were examined and possible etiological causes of severe demarcated opacities were tested.

Results & conclusions: The hypomineralized enamel was mainly located in the buccal enamel of the teeth and had a high degree of porosity extending from enamel-dentin-junction with a distinct border to the normal cervical enamel. Teeth diagnosed MIH had lower hardness values in hypomineralized enamel and differences in the chemical composition. Bacteria were observed in the enamel and deep into the dentin. Ozone treatment for 20 seconds or more was effective to kill oral microorganisms. Significant relations were found between MIH in first molars and breast feeding more than 6 months, late introduction to gruel and infant formula (later than 6 months). The onset for the hypomineralized enamel was estimated to around 200 days from start of the enamel mineralization.

The overall goal of this thesis was to broaden our knowledge of chronic intraoral pain. The research questions were: What methods can be used to differentiate inflammatory, odontogenic tooth pain from pain that presents as toothache but is non-odontogenic in origin? What is the prognosis of chronic tooth pain of non-odontogenic origin, and which factors affect the prognosis? Atypical odontalgia (AO) is a relatively rare but severe and chronic pain condition affecting the dentoalveolar region. Recent research indicates that the origin is peripheral nerve damage: neuropathic pain. The condition presents as tooth pain and is challenging to dentists because it is difficult to distinguish from ordinary toothache due to inflammation or infection. AO is of interest to the pain community because it shares many characteristics with other chronic pain conditions, and pain perpetuation mechanisms are likely to be similar. An AO diagnosis is made after a comprehensive examination and assessment of patients' self-reported characteristics: the pain history. Traditional dental diagnostic methods do not appear to suffice, since many patients report repeated care-seeking and numerous treatment efforts with little or no pain relief. Developing methods that are useful in the clinical setting is a prerequisite for a correct diagnosis and adequate treatment decisions. Quantitative sensory testing (QST) is used to assess sensory function on skin when nerve damage or disease is suspected. A variety of stimuli has been used to examine the perception of, for example, touch, temperature (painful and non-painful), vibration, pinprick pain, and pressure pain. To detect sensory abnormalities and nerve damage in the oral cavity, the same methods may be possible to use. Study I examined properties of thermal thresholds in and around the mouth in 30 pain-free subjects: the influence of measurement location and stimulation area size on threshold levels, and time variability of thresholds. Thresholds for cold, warmth and painful heat were measured in four intraoral and two extraoral sites. Measurements were repeated 3 times over 6 weeks, using four sizes of stimulation area (0.125-0.81 cm2). The threshold levels were highly dependent on location but less dependent on measuring probe size and time variability was small, and this knowledge is important for the interpretation of QST results. Study II applied a recently developed standardized QST examination protocol (intended for use on skin) inside the oral cavity. Two trained examiners evaluated 21 pain-free subjects on three occasions over 1-3 weeks, at four sites-three intraoral and one extraoral. Most tests had acceptable reliability and the original test instruments and techniques could be applied intraorally with only minor adjustments. Study III examined the value of cone-beam computed tomography (CBCT) in pain investigations. Twenty patients with AO and 5 with symptomatic apical periodontitis (inflammatory tooth pain)

Aim: The main aim of this thesis was to investigate how attitudes influence the latent and manifest need, desire, demand, and utilization for dental implant treatment, considering the gatekeeping process between need and demand, and between demand and utilization of dental treatment.

Material and methods: A conceptual analysis of the need and demand concept from the literature was a first step in the study. A second step was to examine changes in attitudes toward desire for implant treatment over time, also in relation to dental status, in a population of middle aged and older individuals in Sweden based on two questionnaire studies, one in 1989 and the other in 1999 among the same 3000 participants. The individuals who responded both in 1989 and 1999 constituted a panel of 56% of the 1989 survey sample. Logistic regression models were done with desire of implant treatment as dependent variable. In paper V, a qualitative study using grounded theory was done on the treated patients' subjective perspective on receiving a fixed implant-supported denture.

Results: An emancipatory perspective with the patient-dentist dialogue was regarded as central for an optimal treatment result in the prosthetic treatment decision-making process. A main finding was that need is established only in a communicative dialogue with mutual respect between the profession and the patient. The study implied that the gatekeeping concept relates to a complex process rendering great differences between demand and actual utilization. The main result from the questionnaires was the huge increase in interest for implant-treatment from 1989 to 1999. In 1999 almost all (94%) of the study population expressed desire for implant treatment; as many as 92 % percent of those who did not express a desire for implants in 1989 had changed their mind 10 years later. The regression analysis showed that older people, non-city residents, and those with one or several missing and unreplaced teeth, changed desire for implant treatment between the study years. Effects of age, residence, and better dental status disappeared during the ten year study period. Those edentulous and those with removable dentures expressed less desire than those with all teeth remaining, or only one or a few teeth missing, in 1989. High income significantly increased the probability to desire implant treatment for the study panel at both study occasions. The qualitative study, using the method for grounded theory, gave as core category and main finding the importance of the patients' trust and confidence in the dentist and his/her staff, in the process of transforming desire for dental implant treatment into manifest demand, and also making it more likely for the patients' to become satisfied with the treatment result regardless of complications.

Conclusion: There is no objective need in prosthodontic treatment. Manifest need and de

Unilateral posterior crossbite of dento-alveolar origin is a transverse discrepancy of the maxillo-mandibular relationship and is one of the most common malocclusions in the mixed dentition. If untreated, the crossbite and the abnormal lateral movement of the lower jaw may strain the orofacial structures, causing adverse effects on the temporomandibular joints, the masticatory system and facial growth. Thus, early orthodontic intervention is usually undertaken to correct the condition at the mixed dentition stage and the orthodontist may choose from a range of treatment methods. The method of choice for orthodontic treatment should not only be clinically effective, with long-term stability, but also cost-effective. The overall aim of this thesis was to compare and evaluate different methods of correcting unilateral posterior crossbite, in terms of clinical effectiveness, stability and cost-effectiveness. The approach was evidence-based; randomized controlled trial (RCT)-methodology was used in order to generate a high level of evidence.

In the late 1990s a new imaging modality, Cone Beam CT (CBCT) that enables high quality three-dimensional imaging at lower doses than Computed Tomography (CT), was introduced in dento-maxillofacial imaging. In 2005 the Swedish Council on Health Technology Assessment (SBU), in a review of scientific articles on Malocclusions and Orthodontic Treatment in a Health Perspective, found low or contradictive evidence for an association between orthodontic treatment and risks for negative side effects. It was apparent that some of the issues raised only could be addressed by the use of a radiographic technique enabling three-dimensional imaging with high accuracy and reproducibility. A new medical technology needs to be evaluated before implemented in research. This was the aim of two initial studies that, in vitro, examined the accuracy and precision in CBCT imaging using a Plexglas object and a dry human skull and, in vivo, assessed its reproducibility in 13 patients. The results showed small differences between actual values and those obtained from measurements in CBCT tomograms and high reproducibility in measurements of root lengths and marginal bone levels. A prospective radiographic study aimed to investigate root resorption and marginal bone level alterations during orthodontic treatment was conducted on 152 adolescent patients with a common type of malocclusion. CBCT examinations were made before (Baseline) and after treatment (Endpoint) and, in a randomly chosen group of 97 patients, six months after treatment initiation. Root lengths, from those of incisors to those of first molars, and the marginal bone height at root surfaces around the teeth were measured in multiplanar reconstructed tomograms. The results showed that 95% of the patients had at least one tooth with a root resorption > 1 mm. Maxillary lateral incisors and premolars were most often affected and showed the most severe resorptions. Resorptions were also found at buccal and palatal root surfaces, only accessible with a tomographic technique. Jaw, tooth group, and root length at the six-month examination were significantly associated with the degree of root resorption at Endpoint. Before treatment start, large differences in marginal bone height were found, particularly between tooth surfaces. At the end of treatment large changes in bone height among teeth and tooth surfaces could be seen. The largest changes were found at lingual and buccal surfaces, that is, surfaces that cannot be evaluated in conventional radiographs. In contrast, proximal surfaces at posterior teeth, hitherto subjected to most research, showed only small changes. The decrease of marginal bone height was larger in the mandible than in the maxilla and larger in girls than in boys, with respect to palatal/lingual surfaces. A high quality CBCT technique is well suited for research on root resorption and marginal bone level changes during orthodontic treatment as it provides access to anatomic structures th

Loss of teeth can affect a person's appearance and functions such as eating and speaking. There is thus a need for prosthetic rehabilitation to improve quality of life. For many patients, a fixed dental restoration is preferred, and a common restoration is a porcelain-fused-to-metal bridge retained by teeth or implants. Metal-based restorations can potentially cause adverse reactions though, and this is cause for the search for alternative materials. All-ceramic materials are characterized by strong atomic bonds that make them reluctant to react with the environment, and thus unlikely to cause adverse reactions. All-ceramic materials have other attractive material properties and excellent aesthetic properties and have been successfully used in dentistry, mostly for smaller anterior restorations. Ceramics, however, do not withstand tensile forces as well as metals, and are susceptible to brittle fractures with the connector area being especially prone to fracture. More recently, a new type of ceramic material, based on zirconium dioxide, has been developed. Yttria-stabilized tetragonal zirconia polycrystal, Y-TZP, has a unique ability to resist crack propagation by being able to transform from one crystalline phase to another, and the resultant volume increase stops the crack and prevents it from propagating. This material has the potential to be used for larger restorations and in the molar area. Not enough information, however, is available on clinical follow-up of zirconia-based restorations, especially long-term, and information about all-ceramic restorations supported by implants is lacking. The aim of this thesis was to evaluate designs of zirconia-based restorations in relation to achieving increased fracture resistance and evaluate the clinical performance of implant-supported zirconia-based restorations. In paper I implant-supported all-ceramic fixed partial dentures of two different ceramic materials were compared; a zirconia-toughened alumina material (group 1) and a fully-sintered Y-TZP material (group 2). Eighteen patients were randomly divided between the two groups. At the one-year follow-up, all restorations were in function and no complete fractures were noted. However, fractures of the veneering material were noted. There was a significant difference between the two materials: 54% of the restorations in group 2 showed veneer fractures compared to 8% of the restorations in group 1. Paper IV is a five-year follow-up of the same patient groups. All restorations were still in function without complete fractures, but an increase in veneer fractures was noted: 69% of the restorations in group 2 showed veneer fractures compared to 17% in group 1. In paper II the fracture strength was evaluated for 4-unit Y-TZP fixed dental prosthesis frameworks with different connector dimensions: 2.0, 2.5, 3.0, 3.5 and 4.0 mm. The results showed a significant increase in load at fracture for each increase in connector diameter and recommendations

Gold and other alloys have long been used for the production of crowns and bridges as replacements for damaged or lost teeth. However, doubts have arisen on the suitability of using these materials for dental restorations, as gold has also shown a capacity to cause side-effects such as allergic reactions. This is especially valid for alloys, which during the last decades have been used as porcelain-fused-to metal restorations. This fact has led to an interest in using titanium instead of these alloys. Trials to use titanium for this purpose were initiated in Japan in the early 1980s. Titanium as an unalloyed metal differs in two aspects from the above named alloys: it has a phase transformation at 882 degrees C, which changes its outer and inner properties, and it has an expansion that lies between that of the porcelain types available on the market at the time. In Japan a technique for casting titanium was developed, where the after-treatment of the casting was elaborate, to re-establish the original properties of titanium. The porcelain developed for veneering had shortcomings as the rendering produced a rough surface and non satisfactory esthetics. In Sweden a new concept was introduced in 1989. Here the processing of titanium was performed by industrial methods such as milling, spark erosion and laser welding. The idea behind this was to avoid phase transformation. During the 1990s a number of porcelain products were launched and a vast number of both laboratory and clinical studies were performed and published, with varying results. In the first study of this thesis a prospective clinical trial was performed at a public dental health clinic in Sweden. Twenty-five patients were provided with 40 copings of pure titanium, which were veneered with porcelain. After 2 years 36 of these crowns were evaluated and the patients were also interviewed regarding problems such as shooting pains or difficulties in cleaning around the teeth that were crowned. This evaluation showed generally unchanged values for color, form, surface and fit. Regarding surfaces, one porcelain fracture was registered (3%). The patient responses were positive and no case of sensitivity was reported after 2 years, but in 3 cases food impaction was reported. The second study is a systematic review of published articles on bond strength between titanium and porcelain. The review made comparisons of bond strength using three-point bending tests between different porcelain bonds to different alloys and to titanium, between different brands of porcelain and titanium, with porcelain following various types of processing of the titanium surface, with different compositions of the porcelain and with different firing conditions. Generally it could be seen that with this type of test (three-point bending) the bond strength between porcelain and titanium was lower than with alloys. It was also seen that there are differences in bond strengths between different brands of porcelain, t

Unlabelled: Professional organisations present challenges in management compared to producing companies, as control of the work lies within the professional groups themselves. Management in the Public Dental Health Service (PDHS) has an added difficulty in the two-tiered political governance in Swedish public dentistry. The aim of this thesis was to contribute to better understanding of the organisation and management of Human Service Organisations, especially the PDHS in Sweden, thereby contributing to long-term sustainability with due regard to the professionals. The aim was also to point to some future difficulties facing the PDHS and possible solutions to these. Four papers are included in the thesis. The first paper set out to define the professions in dentistry in Sweden from theories on professions. Dentists and, to a lesser degree; dental hygienists were the identified professional groups. The second paper scrutinised the external environment for dentistry in Sweden in the form of political decisions, i.e., laws and regulations. The findings were that there can be a gap between the formal objectives and the factual behaviour from the political level, and that certain politically attractive ideas might reoccur at a later time despite good scientific arguments against them. Also indicated in this paper were ways to influence the political processes, by active participation in the early stages of decision-making The third paper dealt with the heads (CDOs) of the PDHS in the counties and is based on a questionnaire to them on management. It was found that ideas on management and organisation usually were embedded in the way the respective county council was organised. A strong belief in advantages of scale was noted, both for administration and also for dental care itself. The fourth paper compared overall job satisfaction among publicly employed dentists in Denmark and Sweden. A focus on size of clinic, on professional development and on influence at the work place was found to be important. The Danish dentists were generally more satisfied with their overall job situations than the Swedish ones. One explanation might be found in the environment for the respective service, with a much stronger element of competition in Sweden. Another aspect could be that the expectations of the Danish dentists might be more realistic when they entered the public service. In an appendix the history of the Swedish Public Dental Health Service is outlined.

Conclusions: Dentists in Sweden are an established profession and dental hygienists are an emerging profession; they and society would benefit from a clearer delineation and definition of their unique competences. Political decision-making is not necessarily rational, and garbage can models or similar can give a better understanding of political processes. CDOs have a widespread belief in advantages of scale in administration as well as in care, which may pose futur