SAMMANFATTNING Bakgrund: Kunskapen om helkeramiska kronor är begränsad och få studier är gjorda inom allmäntandvård. Syfte: Projektet hade i syfte att undersöka femårsöverlevnaden för helkeramiska kronor samt att utvärdera om patientens kön, typ av porslin, typ av cement, rotfyllnadsstatus och tandposition påverkade överlevnaden. Material och metod: Studien är en retrospektiv journalstudie. Samtliga patienter som under åren 2008-2009 behandlades med en helkeramisk, krona på en kindtand inkluderades, totalt 297 kronor. Kronorna följdes sedan upp i fem år. Resultat: Kronöverlevnaden efter fem år var 91,6 %, ingen skillnad sågs mellan kronor utförda på kvinnor och män eller beroende på typ av porslin och typ av cement. Endokronor hade en något lägre överlevnad, 82,8 %, jämfört med fullkronor, 90,9 % och onlaykronor 100 % (p=0,081). Ingen skillnad sågs i överlevnad beroende på tandposition. Slutsats: Femårsöverlevnaden för keramiska kronor i sidopartier utförda inom allmäntandvården är god Den vanligaste komplikationen, oavsett krontyp, var lossnad krona.

Intra-oral  halitosis  (bad  breath)  is reported  to affect  15-83 % of the adult population. Having intra-oral halitosis is a social and psycho-logical handicap, and may cause people in the  person’s social circle to increase the physical distance or to turn their faces in another direction to avoid the unpleasant smell from the exhaled air. Such behaviours may affect the individual’s self-confidence resulting in insecurity in social and intimate relations. The oral health-related quality of life status has also been reported to be lower in individuals with halitosis. Approximately 90% of what is considered as bad breath is the result of the degradation of organic substrates (proteins) by an- aerobic bacteria of the oral cavity. Intra-oral halitosis can be  assessed using both subjective and objective methods to evaluate the subject’s exhaled air. The most common one and the one often referred to as the ”gold standard”, is the organoleptic scoring system (OLS). OLS is a subjective method  evaluating  the  strength  of halitosis in exhaled air using a scale from 0-5. One objective  method to assess the presence of volatile sulphur compounds in exhaled air is to use a sulphide monitor measuring the total sum of the volatile sulphur  compounds  (T-VSC) in exhaled  air.  The three  gases  (hydrogensulphide (H2S), methyl mercaptan (MM) and dimethyl sulphide (DMS)) in exhaled air related to intra-oral halitosis can be assessed separately using a simplified gas chromatograph. Different treatment models such as periodontal treatment, tongue scraping and rinsing with Zn ion containing products have been used to reduce intra-oralhalitosis. The  present  thesis  has  evaluated  the  efficacy of  different treatment models in the treatment of intra-oral  halitosis.

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The purpose with this in-vitro study is to examine the difference in marginal and internal gap width between bis-acryl composite resins (Luxatemp Fluorescence) and IPS Empress crowns. A maxillary left first phantom Frasaco molar tooth placed in a maxillary Frasaco model was prepared for an all-ceramic crown. 15 provisional Luxatemp crowns were made and silicon replicas of the intermediate space between the prepared tooth and the inside of the Luxatemp crowns were made to measure the internal and marginal gap width. The silicon replicas were divided into four pieces and the gap width was measured at 240 points under microscope. The results were compared to data on internal and marginal gap width for an IPS Empress crown from a published study. The results of this present study showed a slight difference in marginal and internal gap width between the Luxatemp crowns and the IPS Empress crowns (control). The Luxatemp crowns have a slightly minor overall gap width than the IPS Empress crowns. The marginal and occlusal gap width was slightly wider for the Luxatemp crowns (205µm) than for the IPS Empress crowns (170µm). The conclusion of this study is that provisional materials made of bis-acryl composite resins give a marginal and internal fit that can be compared to the marginal and internal fit of an IPS Empress crown.

The clinical knowledge and skills of dental students attending to different Swedish universities is constantly under discussion. In this study ten students attending their eighth semester at the Department of Odontology, Faculty of Medicine, Umea University Sweden were recruited to evaluate if it would be more challenging to prepare abutment teeth for fixed partial dentures (FPD) with the abutment teeth far apart in the dental arch. Questioning whether it is more difficult to achieve an adequate total convergence angle (TOC) for FPD with abutment teeth closer to each other than one with them further apart. The hypothesis that teeth further apart give a larger TOC. For the experiment the students used dental mannequins with plastic maxillae and plastic teeth provided by the simulation clinic at the university. Their task was to prepare for two separate FPD, one with the abutment teeth 14; 16 and a second 21; 13; 15. After preparation, the teeth were drilled and had metal posts placed in them, the posts representing a normal that the TOC could be measured against. Still photos of the plastic maxillae were taken using the program Shape 3D Viewer. A tangent was drawn to measure the TOC. An adequate TOC for crown retention was considered: 10-22 degrees in both mesio-distal and bucco-palatinal plane axis. The results for the two tested models of FPD were relatively similar, likely because the students got to practice preparation for the shorter and FPD first. In conclusion, this study showed no noteworthy difference between the first and second FPD preparation.

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This thesis constitutes a summary of the following series of studies: I Autoradiographic studies on the distribution of zinc-65 in mice. In collaboration with Rune Söremark. The Journal of Nutrition 94,6, 1968. II Comparative study of distribution of injected zinc 65 in the mandibularcondyle and other tissues in rat as determined by gammascintillation. Acta Radiologica, Therapy Physics Biology 1970. Preprint. III Concentration of zinc in some hard and soft tissues of rat determinedby neutron activation analysis. Acta Radiologica, TherapyPhysics Biology 1970. Preprint. IV The distribution of 65Zn in the endochondral growth sites of themandibular condyle and the proximal end of the tibia in youngrats.—An autoradiographic and gamma scintillation study. OdontologiskRevy, 1970. Preprint. V Morphologic and autoradiographic observations on the effect ofzinc deficiency on endochondral growth sites in the white rat. Incollaboration with Ulf Friberg, Stefan Lohmander and TorstenÖberg. Odontologisk Revy, 1970. Preprint. VI The zinc concentration in hard and soft tissues of the rat. Theinfluence of zinc deficient feeding. Acta odontologica Scandinavica,1970. Preprint. These studies will be referred to in the following by the appropriate Roman numerals. / digitalisering@umu.se

digitalisering@umu.se

No description available.