Background: Substandard technical quality of root fillings is strongly correlated with apical periodontitis. The introduction of Nickel-Titanium rotary system has improved the technical quality. However, the overall treatment outcome of root canal treatments has not improved. Root canal treatment has been shown to be associated with stress, anxiety and lack of control.  Aim: To investigate the experience of endodontic treatment among general dental practitioners with focus on difficulties and barriers.  Methods: A digital questionnaire survey was sent by email to general dental practitioners (GDPs) in five counties in northern Sweden. The participants were asked questions regarding general information and questions related to their endodontic work divided into three main groups; the patient, education and stress, time and material.  Results: The response rate was 58% (n=96). Sixty percent of the participants had a very or quite positive attitude towards endodontic treatment. Sixty-three percent often or sometimes experience stress when performing root canal treatment. Lack of time was frequently answered as a cause of stress (59%). Most respondents had a good (40%) or quite good (54%) education in endodontics. Twenty-two percent of the GDPs felt very confident and 62% felt quite confident when performing root canal treatment. Conclusion: The participants generally had a positive attitude toward endodontic work. Although, stress was frequently experienced when performing root canal treatment, in many situations due to lack of time. Results from the present study indicates that education is of great value to further develop the dentists’ confidence in endodontics.

ABSTRACT Aim: To understand endodontic infections and their prognosis knowledge of which bacteria are present, viable, and part of perpetuating the late stages of the infection. The aim of this study was to investigate three different methods for mapping the composition of the microbiota in infected root canals. Methods: (i)Culturing on agar discs; (ii)real-time polymerase chain reaction (qPCR) processing; and (iii)qPCR processing of samples pre-treated with propidium monoazide (PMA). Samples were collected from 32 teeth and stored in buffer solution. Culturing was conducted on Fastidious Anaerobe Agar plates using 200 µL sample solution. Another 400 µL was treated with PMA dye and photoactivation prior to qPCR processing, while the remaining 400 µL was processed by qPCR without pretreatment. The sampled diagnoses were asymptomatic apical periodontitis, asymptomatic apical periodontitis with sinus tract, and symptomatic apical periodontitis. Results: The study found no significant difference in amount of bacteria between the three diagnoses, but found that different methods yielded significantly different results when applied to each diagnosis. qPCR detected the highest absolute numbers of bacteria, and qPCR with PMA the lowest. Conclusions: Results indicate that different methods yield different results, but that the diagnoses do not differ much in terms of bacterial load. To confidently conclude whether or not there is a connection between diagnosis and amount of bacteria, a larger sample size is needed. The results in this study are suspected to be skewed by compromised data, and no certain conclusions can be drawn.

No description available.

Relationship between oral health-related quality of life and teeth whitening Summary Aim: The aim of the study was to study the relationship between oral health-related quality of life and teeth whitening. Method: Literature Study. Scientific articles were searched in databases DOSS, PubMed and Medline with keyword combinations "Oral health-related quality of life" AND "teeth whitening" and "quality of life" AND "teeth whitening". The literature study included 13 quality-reviewed articles. Results: The thematic analysis resulted in three main themes and under each central main theme has several sub-theme identifiers. Main themes showed that there was a connection between oral health-related quality of life and teeth whitening: Aesthetic impact, Psychological impact and Pain impact. Teeth whitening led to reduced aesthetic anxiety, improved aesthetic self-perception, color change, reduced discomfort, improved self-confidence that had a positive effect on the oral health-related quality of life. On the other hand, teeth whitening could cause tooth sensitivity and soft tissue irritation, which had a negative effect on the oral health-related quality of life. Keywords: Bleaching, discolored teeth, quality of life , whiter teeth.

No description available.

Objectives: Azithromycin is a second-generation macrolide active against a wide range of bacteria, including obligate anaerobes implicated as bacterial pathogens in human periodontitis. Clinical studies indicate short-term systemic azithromycin therapy to be beneficial in the treatment of acute periodontal abscesses and as an adjunct to mechanical periodontal therapy of periodontitis patients. Only sparse recent data is available on the susceptibility or resistance of putative periodontal bacterial pathogens to azithromycin, particularly among subgingival isolates from periodontitis patients residing in the United States. Thus, the present degree to which major periodontal bacterial pathogens in United States periodontitis patients exhibit resistance to azithromycin is not known. As a result, the purpose of the present study was to determine the prevalence of in vitro resistance to azithromycin, as compared to metronidazole, among selected red/orange complex periodontal pathogens isolated from severe periodontitis patients in the United States. / Oral Biology

SAMMANFATTNING Vedbildning är en underliggande mekanism för så skilda områden som industri, boende och en hållbar miljö. Vedbildning sker i det vaskulära kambiet där organiserade celldelningar åtföljs av differentiering till specialiserade vedceller. Ved består av sekundärt xylem som är starka, stora celler med tjocka cellväggar som är lignifierade. Dessa celler transporterar vatten och näringsämnen samt ger trädet dess styrka. Grunden för de starka cellerna är en avancerad komposit bestående av cellulosafibrer tvärbundna av hemicellulosa och slutligen ingjutet i lignin. Denna fiberkomposit är den sekundära cellväggen i vedartade växter. Celldelning och differentiering regleras genom att sätta igång och stänga av gener. Proteiner som kodas av dessa gener utför de viktigaste funktionerna i cellerna. De styr hela maskineriet som upprätthåller cellernas struktur och funktion, underhåller tillväxt samt tillverkar nödvändiga produkter såsom cellväggskolhydraterna. Träbioteknologiforskningsgruppen har varit en del av ett kraftfullt åtagande att identifiera de proteiner som är ansvariga för nyckelprocesser i vedbildning. Detta har utförts genom att övervaka genexpressionen vid olika tidpunkter av vedcellsmognad i Populus tremula x tremuloides. Här beskriver vi undersökningen av proteiner som är inblandade i cellexpansion och bildandet av sekundär cellvägg liksom utvecklandet av ett modellsystem som kommer vara en hjälp i den funktionella analysen av cellulosabiosyntes. Expansin är ett protein som verkar i cellexpansionen i alla växtens vävnader. Vi har studerat ett expansin, PttEXPA1, som visat sig vara särskilt närvarande i celler som genomgår vedbildning. Dessutom har vi undersökt glykosyltransferaser som tycks spela en viktig roll i bildandet av sekundär cellvägg. En av dessa, PttGT43A har uttryckts i jästen Pichia pastoris och i baculovirusinfekterade insektsceller. Dessvärre var proteinnivåerna för låga för biokemisk karakterisering. Dessutom har vi demonstrerat att flytande cellkulturer av hybridasp kan användas som ett modellsystem för cellulosabiosyntes. Genom att bemästra proteinerna som är ansvariga för vedbildning får vi verktyg att utveckla skogsproduktsmarknaden. En vision är nya produkter som till exempel träd som växer snabbare, ändrade fiberegenskaper, produktion av vedkolhydrater såväl som utvecklandet av intelligenta material genom biomimetisk ingenjörskonst. / ABSTRACT Wood formation or xylogenesis is a fundamental process for so diverse issues as industry, shelter and a sustainable environment. Xylogenesis originates from the vascular cambium where organised cell divisions are followed by differentiation into specialised wood cells. Wood is comprised of secondary xylem, rigid large cells with thick cell walls that are lignified. These cells transport water and nutrients as well as give the tree its strength. The basis for the sturdy cells is an advanced composite made up of cellulose fibers cross-linked by hemicelluloses and finally embedded in lignin. This fiber-composite is the secondary cell walls of woody plants. Cell division and differentiation is regulated by switching on and off genes. Proteins encoded by these genes execute the major functions in the cells. They steer the entire machinery operating the structure and function of the cells, maintaining growth and synthesising essential products such as the cell wall carbohydrates. The Wood Biotechnology research group has been part of a massive undertaking of identifying proteins responsible for the key processes of xylogenesis. This has been achieved by monitoring the gene expression at different time points of wood cell maturation in Populus tremula x tremuloides. Here we describe investigation of proteins involved in cell expansion and secondary cell wall formation as well as the development of a model system that will aid the functional analysis of cellulose synthesis. Expansin is a protein involved in cell expansion in all tissues of the plant. We have studied one expansin, PttEXPA1, found to be especially abundant in cells undergoing wood formation. Also, we have examined glycosyltransferases that seemingly play a part in secondary cell wall formation. One of these, PttGT43A is expressed in the yeast Pichia pastoris as well as in baculovirus infected insect cells. However, protein levels were too low for biochemical characterisation. We have also demonstrated that hybrid aspen cell suspension cultures can be used as a model system for cellulose synthesis. By mastering proteins involved in xylogenesis we acquire the tools to improve and develop the wood product market. New products envisioned include e.g. faster growing trees, changed fiber characteristics, production of wood carbohydrates as well as invention of intelligent materials by biomimetic engineering. / QC 20101122

Sammanfattning Syfte: Syftet med studien var att undersöka om böjhållfastheten pålitiumdisilikatbaserad glaskeram som har framställts genom pressteknik påverkasav en energidryck (NOCCO) och apelsinjuice motsvarande 13-års förbrukning. Material och metod: Totalt tillverkades 30 provkroppar genom att pressas i IPSe.max Press®. Provkropparna delades in i tre grupper, varav två grupper utsattesför sura drycker (EMA & EMN) och en grupp som kontrollgrupp (EMK). Antaletprovkroppar var 10 i varje grupp med måtten 12 mm i diameter och 1,7 mm itjocklek. Alla grupper bevarades i varsin behållare fylld med respektive dryck.EMA förvarades i 8°C apelsinjuice, EMN förvarades i 8°C NOCCO focus 4legend soda och EMK förvarades i 37°C destillerat vatten. Efter 14 dygn utsattesprovkropparna för biaxialt böjhållfasthetstest och efteråt analyserades resultatetmed One-way ANOVA, Tukey’s test med en signifikansnivå på α= 0,05. Resultat: Resultatet visade att det fanns en signifikant skillnad mellan grupperna.Testet påvisade att EMK hade lägst medelvärde (215 MPa) och EMA hade högstmedelvärde (432 MPa). Gruppen EMK hade en signifikans i jämförelse medsamtliga grupper medan EMN och EMA inte uppvisade signifikant skillnadgentemot varandra. Slutsats: Följande slutsatser i föreliggande invitro studie kan dras; sura dryckerhar ingen påverkan på böjhållfastheten hos litiumdisilikatbaserade glaskeramerframställt genom pressteknik. / Abstract Aim: The aim of the study is to investigate whether the strength of lithiumdisilicate-based glass ceramics that have been produced by pressing technologyare affected by an energy drink (NOCCO) and orange juice after treatmentcorresponding to 13 years of consumption. Material and method: A total of 30 specimens by IPS e.max Press® weremanufactured, then divided into two groups exposed to acidic beverages (EMA &EMN) and one group was assigned as a control group (EMK) with 10 specimensin each group, measuring 12 mm in diameter and 1.7 mm in thickness. EMA waspreserved with 8 °C orange juice, EMN was preserved with 8 °C NOCCO focus 4legend soda and EMK was preserved in 37 °C distilled water. After 14 days, thespecimens were subjected to biaxial flexural strength and subsequently analyzedwith One-way ANOVA, Tukey's test with a significance level of α = 0.05. Result: The results showed that EMK had the lowest mean (215 MPa) and EMAhad the highest mean (432 MPa). It turned out that EMK had a significance incomparison with all groups, while EMN and EMA have no significant differencefrom each other. Conclusion: The following conclusions are drawn from this in vitro study; acidicbeverages have no effect on the flexural strength of lithium disilicate-based glassceramics produced by pressing technology.

Background: Wisdom tooth surgery is one of the most common dentoalveolar surgical procedure carried out by dentists to remove impacted wisdom teeth. Complications may occur during or after all different types of surgical procedures. At the dentistry program at Umeå University, the students in the 8th term perform operative extraction of a mandibular wisdom tooth under the guidance of an oral surgeon. Although this has been a part of the dental students clinical training for some time, there is no evaluation of the rate of complications that might occur after surgery performed by students. Aim: The aim of this study is to determine if a difference in frequencies and type of complications is present when the operative procedure is carried out by dental students or by oral surgeons. Methods: A retrospective study including data of 74 cases that underwent wisdom tooth surgery done by oral surgeons or dental students at Umeå University Hospital in Sweden. All cases were matched based on age, gender, and degree of difficulty of the surgery and then radiologically evaluated by the authors. Thereafter complications were recorded and divided into subgroups of intraoperative or postoperative complications. Results: The complication rate in total was 31% and there was no significant difference regarding complications between dental students and oral surgeons. Conclusion: As no higher degree of complication rate is present when students perform surgery, the authors of this study advocates continued operative extractions of mandibular wisdom teeth for dental students at the dentistry program at Umeå University.

The objective of this study was to evaluate the faculty perception of case-based learning weekly seminars held in Kuwait University-Faculty of Dentistry. Case-based learning (CBL) has been described in the dental literature as an important method for distilling the basic knowledge learned in texts and lectures and applying it to a patient's circumstances. To enhance the integration between disciplines and minimize isolated learning, the Faculty of Dentistry-Kuwait University created comprehensive dental care 3 (CDC) seminars. Those weekly seminars include real cases presented by fifth, sixth, and seventh-year clinical year students, facilitated by a case-based teaching and learning approach. Literature suggests that a shift to a more problem-based learning curriculum can represent a substantial challenge for many faculty members who may be unfamiliar with the process. This research investigated the experiences and perceptions about CBL of faculty in one dental school. Subjects were invited to volunteer to answer a questionnaire. The survey included 25 "forced choice" questions and three open-ended optional questions. Most participants believed that faculty members do not understand the difference between problem-based learning and case-based learning. In addition, results showed that casebased learning was found to be beneficial not only for students, but also for faculty. Although the majority of the participants agreed that case-based learning was not a useful method for preparing students for written assessments, the majority agreed that case-based learning improves the integration between theory and clinical application. It was noted that case-based learning can be time consuming for both faculty and students. In general, faculty members agreed that case-based learning improves clinical skills, treatment planning skills for comprehensive dental patients, and clinical problem-solving as students progress from their fifth to seventh years.