Purpose  To evaluate the impact of implant length on failure rates between short (<10 mm) and long (≥10 mm) dental implants.   Materials and methods A search was undertaken in three electronic databases, complemented by manual search of some journals. Implant failure was the outcome evaluated, with the estimate of relative effect expressed in risk ratio (RR). Heterogeneity among studies was evaluated by I2statistic. Inverse variance method was used for random- or fixed-effects models. Quality assessment of the studies was performed, and a funnel plot was drawn. A meta-regression was performed in order to verify how the RR was associated with the follow-up time.   Results The reviews included 353 publications. Altogether, there were 25,490 short implants and 159,435 long implants. Pairwise meta-analysis showed that short implants had a higher risk of failure than long implants (RR 2.437, p<0.001). The meta-regression observed that the follow-up time did not have any effect of the RR of failure between short and long implants. A sensitivity analysis plotting together only the studies with follow-up up until 7 years, resulted in an estimated increase of 0.6 in RR for every additional month of follow-up.   Conclusion Short implants showed (< 10 mm) a 2.5 times higher risk of failure than long implants (≥ 10 mm). Implant failure is multifactorial and the implant length is only one of the many factors contributing to the loss of implant. A good treatment plan and the patient’s general health should be taken into account when planning for an implant treatment.       Keywords: dental implant, failure, implant length, systematic review, meta-analysis

Bakgrund: Radiologi används inom tandvårdsyrket för diagnostik. Det är strikt reglerat via lagar och förordningar så att patienter inte i onödan utsätts för joniserande strålning, vilket innebär att en tandläkare måste ha tillräcklig kunskap om dess användning. Detta inkluderar kunskap om när och var den radiologiska metoden kan användas och vilken bildteknik som är mest pålitlig. Dessutom är det viktigt att kunna tolka röntgenbilder och därigenom kunna identifiera eventuell patologi i de undersökta områdena. Syftet: Jämföra teman som ingår i olika kursmål inom odontologisk radiologi vid tandläkarutbildningar vid universitet i Europa. Metod: Kursmål i odontologisk radiologi begärdes från olika tandläkarutbildningar via e-post. Webblänkar från universitet analyserades. En påminnelse skickades ut för att förbättra svarsfrekvensen. Svaren analyserades på ett beskrivande sätt.  Resultat: Studien identifierade 123 tandläkaruniversitet. 23 universitet skickade sina kursmål. 17 av dessa ingick i studien. En skillnad identifierades med avseende på hur kursmålen skrevs. Dessutom fanns skillnader i antalet uttryckta kursmål för specifika radiologiska avbildningsmetoder. Konklusion: Kursmål för studenter inom odontologisk radiologi skiljer sig avseende struktur och innehåll mellan studerade utbildningar. Många universitet saknar delar av teman inom ämnet. Mer ingående forskning inom området är angeläget för att säkerställa en likvärdig utbildning inom odontologisk radiologi för tandläkarstudenter i Europa. / Background: Radiology is used in the dental profession for diagnostics. It is strictly regulated so patients won´t be exposed to unnecessarily ionizing radiation, meaning that a dentist must have adequate knowledge. This include knowledge about when and where the radiographic method can be used, and which imaging technique is the most reliable. Furthermore, being able to interpret the radiographs is essential and thereby able to identify any pathology in the investigated areas.  Aim: Compare the themes that are included in various course objectives in the field of oral radiology at dental universities in Europe. Method: Course objectives in oral radiology were requested from different dental universities by email and weblinks, they were later analysed. One remainder were sent to improve the response rate. The answers were analysed in a descripted way.   Results: The study identified 123 dental universities. 23 universities sent their course objectives. 17 of these where included in the study. A difference was identified as to how course objectives were written. In addition, there was a disparate difference in the number of expressions of the course objectives in according to specific type of radiographic imaging methods.  Conclusion: Course objectives in oral radiology for students at dental universities in Europe differ in terms of structure and content. Many universities have no specific part of themes within the subject.

Syfte Studien handlar om att undersöka ifall tatueringar påverkar uppfattningen om professionalism hos tandläkarstudenter och personal på tandvårdshögskolan i Malmö. Syftet är att lyfta fram vad olika grupper anser om dessa kroppsmodifikationer men också bidra till ökad insikt inom och bland dessa grupper. Material och metod En enkätundersökning granskade deltagarnas förhållning till professionalism gällande tatueringsmotiv, storlek, kompetens, ansvarsfullhet, hygien, etik, pålitlighet, anställningsbarhet och klinikens/yrkesgruppens rykte. Resultat 196 deltagare deltog i studien, 132 studenter och 64 personal. Mellan dessa grupper påvisades ingen statistisk signifikans förutom gällande yrkesgruppens och klinikens rykte. Datan visade att män var mer negativa än kvinnor, yngre kvinnor var mer positiva än övriga deltagare och tatuerade var mer accepterande. Ett stötande motiv eller stor tatuering hade en negativ påverkan på professionalismen. Slutsats Inga skillnader kunde påvisas mellan studenter och personalen gällande synen på professionalism och tatueringar. Variabler som påverkade synen på professionalismen var deltagarnas ålder, kön och om hen var tatuerad eller ej. / Purpose The aim of this study is to investigate whether tattoos affect the perception of professionalism among dental students and staff at the School of Dentistry in Malmö. The purpose is to highlight what different groups think about these body modifications but also contribute to increased insight within and among these groups. Material and method A survey was used to examine participants' attitudes towards professionalism regarding tattoo motifs, size, competence, responsibility, hygiene, ethics, reliability, employability and the clinic / occupational group's reputation. Results 196 participants participated in the study, 132 students and 64 staff. No statistical significance was demonstrated between these groups other than the reputation of the clinic and the occupational group. The data showed that men were more negative than women, younger women were more positive than other participants and tattooed were more accepting. An offensive motive or large tattoo had a negative impact on professionalism. Conclusion No differences could be demonstrated between students and staff regarding the view of professionalism and tattoos. Variables that affected the view of professionalism were the participants' age, gender and whether they were tattooed or not.

Aim: The aim of this study is to investigate if biaxial flexural strength for pressed glass ceramic with glazed, polished and grinded surface is affected by the acidic beverages Coca Cola and red wine. Material and method: 63 specimens were manufactured in IPS e.max Press®, divided into 6 test groups and one control group (KG) with 9 specimens in each group, in the dimensions 12 mm in diameter and in thickness, 1,8 mm without notch and 2,2 mm with notch. The specimens subdivided by different surface treatments; glazed surface (CCG, RVG), polished surface (CCP, RVP) and ground surface (CCS, RVS). Three groups underwent thermocycling for 970 cycles in 8°C Coca Cola® and three groups red wine at room temperature. Results: The results show significant difference between the groups with α=0,001. Biaxial flexural strength test showed that the CCS group had the highest mean value (340 MPa) and CCP the lowest mean value (214 MPa). CCS showed significant differences to all groups except RVP and RVS. Furthermore the RVP group showed no significant difference to any other group and RVS only towards CCP. Conclusion: Within the limitations of this in vitro study the following conclusions can be made; Acidic beverages do not affect the flexural strength for pressed lithium disilicate based glass ceramics. The flexural strength is affected by surface treatment, where grinding with sandpaper results in higher flexural strength. / Syfte: Syftet med föreliggande studie är att undersöka om den biaxiala böjhållfastheten på litiumdisilikatbaserad glaskeram som framställts genom pressteknik med tre olika ytbehandlingar (glansbränd yta eller för att efterlikna ocklusal inslipning eller abraderat slitage) påverkas av de sura dryckerna Coca Cola® och rödvin.Material och metod: 63 provkroppar tillverkades av IPS e.max Press®. Provkropparna delades in i 6 testgrupper, och en kontrollgrupp (KG), á 9 i varje, med måtten 12 mm i diameter och tjocklek 1,8 mm utan notch och 2,2 mm med notch. Provkropparna delades in utifrån olika ytbehandlingar, glansbränd (CCG, RVG), polerad (CCP, RVP) och slipad med sandpapper (CCS, RVS). 3 grupper genomgick termocykling i 970 cykler i 8°C Coca Cola®, och 3 grupper i rödvin i rumstemperatur, varvat med destillerat vatten i 37°C. Därefter utfördes biaxialt böjhållfasthetstest och resultaten analyserades med One-way ANOVA, Tukey’s test, signifikansnivå α= 0,05.Resultat: Resultaten visar att det finns signifikant skillnad mellan grupperna α=0,001. Det biaxiala böjhållfasthetstestet påvisade att gruppen CCS hade högst medelvärde (340 MPa) och CCP hade lägst medelvärde (214 MPa). CCS visade signifikant skillnad jämfört med samtliga grupper, förutom RVP och RVS. Vidare uppvisade RVP ingen signifikant skillnad jämfört med någon av de övriga grupperna och RVS endast mot CCP.Slutsats: Inom denna in vitro-studies begränsningar kan följande slutsatser dras; Sura drycker påverkar inte böjhållfastheten på litiumdisilikatbaserad glaskeram som framställts genom pressteknik. Hållfastheten påverkas beroende på ytbehandling. Genom att slipa ytan med slippapper resulterade det i högre biaxial böjhållfasthet.

Syfte: Syftet med föreliggande studie är att undersöka färgstabiliteten hos manuellt färginfiltrerad högtranslucent zirkonia efter upprepade bränningar.   Material och metod: Fem provkroppar av respektive fabrikat; Prettau® Zirconia (PZ) och M+W Zircon HT (MW) kapades fram ur ofärgade zirkonia-diskar. Provkropparna färgades in manuellt med färgen A3 och torkades därefter under en infraröd lampa. Provkropparna sintrades enligt fabrikanternas anvisningar och en första färgmätning utfördes med en spektrofotometer (VITA Easyshade Advance 4.0) mot en matt grå bakgrund. Där efter utfördes bränningar av provkropparna i fyra cykler. Efter varje cykel utfördes färgmätningar.Medelvärdena för L*a*b*c*h* registrerades. Formlerna CIE76 (∆E*ab) och CIEDE2000 (∆E*00) användes för att räkna ut färgskillnader efter bränncyklerna. Värdena registrerades i SPSS och analyserades med One-way ANOVA, Tukey’s test med en signifikansnivå på α=0,05.   Resultat: Statistiskt signifikanta skillnader (p<0,05) i färgförändring hittades både inom och mellan de båda grupperna (MW och PZ). Färgskillnaderna som uppmättes befann sig inom ramen för vad som anses som en acceptabel (∆E*ab≤2,7 och ∆E*00≤1,8) eller mycket god färgmatchning (∆E*ab≤1,2 och ∆E*00≤0,8).   Slutsats: Inom ramen för studiens begränsningar kan följande slutsatser dras: Upprepade bränningar påverkar färgen hos manuellt färginfiltrerad högtranslucent zirkonia. De färgförändringar som sker är inom ramen för vad som räknas som en ”acceptabel färgmatchning” eller ”mycket god färgmatchning” enligt aktuella gränsvärden. Färgförändringarna som sker är inte iögonfallande och har ringa betydelse kliniskt. Färgen och färgskillnader hos manuellt färginfiltrerad högtranslucent zirkonia är beroende av fabrikat. / Purpose: The purpose of this study is to investigate color stability in manually color infiltrated high translucent zirconia after repeated firings. Material and methods: Five specimens of each manufacturer; Prettau® Zirconia (PZ) and M+W Zircon HT (MW) were cut from uncolored zirconia discs. The specimens were manually colored with shade A3, and dried. The specimens were sintered and a first color measurement was performed with a spectrophotometer (VITA Easyshade Advance 4.0) against a matte gray background. Firings of the specimens were performed in four cycles. After each cycle, color measurements were performed. The mean values for L*a*b*c*h* ​​were registered. The formulas CIE76 (∆E*ab) and CIEDE2000 (∆E*00) were used to calculate color differences after firing cycles. The values were registered and analyzed with One-way ANOVA, Tukey's test with a level of significance at α=0.05.  Results: Statistically significant color differences (p<0.05) were found within and between groups (PZ and MW). The color differences measured were within the range of what is considered an acceptable match (∆E*ab≤2.7 and ∆E*00≤1.8) or a perfect match (∆E*ab≤1.2 and ∆E*00≤0.8).   Conclusion: Within the limitations of this study, the following conclusions can be drawn: Repeated firings affect the color in manually color infiltrated high translucent zirconia. The color changes that occur are within the range of what is considered an “acceptable match” or “perfect match” according to current thresholds. The color changes are not conspicuous and of little importance clinically. The color and color differences in manually color infiltrated high translucent zirconia are dependent on the brand.

SammanfattningSyfteSyftet med föreliggande pilotstudie är att undersöka abrasion på materialen polerad zirkonia (5YSZ) och glansbränd litiumdisilikat och abrasion på antagonist med eller utan termocykling. Emalj utgör referens. De inkluderade materialen är avsedda för CAD/CAM- framställning av monolitiska konstruktioner.Material och metodFrån en zirkoniadisk (5YSZ, Katana zirconia UTML) och tre litiumdisilikatblock (IPS e.max CAD LT) togs totalt sexton provkroppar fram. Åtta extraherade molarer användes som referensgrupp (n=8) och steatitkulor användes som antagonist. Provkropparna för zirkonia och litiumdisilikat utformades rektangulära med måtten 16x14x3,5 mm efter sintring respektive kristallisering. Provkropparnas testytor genomgick olika ytbehandlingar. Zirkoniaprovkropparna polerades till högglans (ZP), litiumdisilikat glansbrändes med glaze (LG) och de extraherade molarerna planslipades och emaljen polerades (EM). Hälften av materialgrupperna tuggsimulerades i 120 000 cyklar med termocykling i temperaturerna 15°C±2°C respektive 55°C±2°C (ZPT, LGT, EMT). Den andra hälften tuggsimulerades i 120 000 cyklar utan termocykling (ZPU, LGU, EMU). Resultaten analyserades med One-way ANOVA, Tukey’s test med en signifikansnivå på α=0,05 i statistikprogrammet SPSS.ResultatHögst materialförlust påvisades i EMT-gruppen och lägst i ZPU-gruppen. Ingen signifikant skillnad kunde påvisas mellan materialgrupperna. Hos antagonistgrupperna påvisade EMT- gruppen högst materialförlust och LGT-gruppen lägst materialförlust. Hos antagonistgrupperna hade EMT-gruppen en signifikant högre materialförlust i jämförelse med övriga antagonistgrupper förutom LGU- och ZPU-gruppen.SlutsatsPolerad ultratranslucent zirkonia, glansbränd litiumdisilikat, och emalj abraderas likvärdigt av antagonister med eller utan termocykling. Polerad ultratranslucent zirkonia och glansbränd litiumdisilikat abraderar mindre mot antagonister än emalj med termocykling. / AbstractPurposeThe purpose of this pilot study is to investigate the abrasion of polished zirconia (5YSZ) and glazed lithium disilicate on antagonist and antagonists’ abrasion on the materials with or without thermocycling, with enamel as reference. The materials are intended for CAD/CAM production of monolithic restorations.Material and methodFrom zirconia (5YSZ, Katana zirconia UTML) and lithium disilicate (IPS e.max CAD LT) sixteen specimens were made. Eight extracted molars were used as reference group (n=8) and steatite balls used as antagonists. The specimens were designed with the dimensions 16x14x3.5 mm. The zirconia specimens were polished to high gloss (ZP), the lithium disilicate glazed (LG) and the enamel ground flat and polished (EM). Half of the groups underwent chewing simulation in 120,000 cycles with thermocycling (15°C ±2°C/55°C ±2°C) (ZPT, LGT, EMT) and the other half without thermocycling (ZPU, LGU, EMU). The results were analyzed with One-way ANOVA, Tukey's test with a significance level of α= 0.05 in the statistical program SPSS.ResultsThe highest material loss was in EMT and the lowest in ZPU. No significant differences could be shown between the material groups. In the antagonist groups, EMT showed the highest material loss and LGT the lowest. In the antagonist groups, EMT had a significant higher loss in comparison with all the other antagonist groups except LGU and ZPU.ConclusionPolished ultratranslucent zirconia, glazed lithium disilicate and enamel are equally abraded by antagonists with or without thermocycling. Polished ultratranslucent zirconia and glazed lithium disilicate abrade less against antagonists than enamel with thermocycling.

Background: At pH 5.5, a clear demineralization of the enamel is seen and is thus considered to be the criticalpH. Bovine milk has several different properties that protect against caries. Calcium and phosphate can prevent the progression of caries as well as some proteins in bovine milk. The replacement of bovine milk with plant-based alternatives has become increasingly common. The aim of this study is to analyze if different milk substitutes create a greater disturbance of the oral cavity’s neutral pH than bovine milk.  Methods: Twenty dental students participated to the study. Saliva samples were collected to analyze pH. Prior to sampling participants were asked to rinse mouth with one product at a time. There were five different products: bovine milk, oat milk, soy milk, almond milk and 10% sucrose solution. Baseline of saliva was taken prior to rinsing. After rinsing samples were taken at two different time points. Between products participants were asked to rinse with water. pH measurements were made after sampling of saliva. The results were analyzed with Microsoft® Excel and SPSS.  Results: Significant differences were found in saliva pH when bovine milk, almond milk and soy milk were compared to 10% sucrose solution at time 15, otherwise no significant differences were found.  Conclusions: No significant difference between bovine milk and milk substitutes was found when rinsing with the products in the pH of saliva.

Aim: The aim is to evaluate the fracture strength and fracture type of long-term water-stored monolithic 3-unit multilayered zirconia fixed dental prostheses (FDPs) depending on connector dimension and placement in disc. Material and method: Thirty-two 3-unit FDPs (212223) of KATANATM Zirconia Yttria Multilayered (YML) were divided into four groups (n=8/group). The EB-groups were placed in Enamel layer/Body layer 1 in the disc, with connector dimensions of 12 mm2 (EB12), or 7 mm2 (EB7). The BB-groups were placed in Body layer 2/Body layer 3, with connector dimensions 12 mm2 or 7 mm2 (BB12 and BB7). All FDPs were long-term water-stored (37° C, one year). They were cemented on die models, cyclic mechanical preloaded (10,000 cycles), followed by fracture strength test. The results were analyzed with one-way ANOVA, Tukey's test, significance level α = 0.05. Fracture type analysis was performed visually and presented descriptively. Result: Group BB12 showed significantly higher strength (2660 N) compared to EB7 with the lowest mean value (1044 N) (p < 0.05). There was no significant difference between the remaining groups. Conclusion: Design and placement of monolithic 3-unit FDPs in multilayered zirconia affects the fracture strength and fracture type.With increased connector dimension the location can be in the upper layer of the disc, and with reduced connector dimension, the location can be in the lower layer. The fractures occur in the connectors of the pontic. With an increased connector dimension and the FDP located in the lower layer, a total fracture will occur / Syfte: Syftet med föreliggande studie är att utvärdera brotthållfastheten och frakturtyp på långtidsvattenförvarade monolitiska 3-leds-broar som framställts i flerskiktad zirkonia med olika konnektordimensioner och placering i disk. Material och metod: Trettiotvå 3-leds-broar med två preparerade tänder, 212223 delades in i fyragrupper (n=8/grupp) beroende på dimensionering av konnektorn och placering i KATANATM Zirconia Yttria Multilayered (YML)-disk. Grupperna EB var placerade i Enamel layer/Body layer 1 i disken,med konnektordimension på antingen 12 mm2 för grupp EB12, eller 7 mm2 för grupp EB7. Grupperna BB var placerade i Body layer 2/Body layer 3 i disken, med konnektordimensionerna 12 mm2 för grupp BB12 respektive 7 mm2 förBB7. Samtliga broar förvarades i vatten, 37° C under ett år. Broarnacementerades på stansmodeller. Efter 24 h genomfördes cyklisk mekanisk förbelastning, 10 000 cykler, följt av ett brotthållfasthetstest. Resultaten analyserades med one-way ANOVA, Tukey’s test,signifikansnivå α = 0,05. Frakturtypsanalys genomfördes visuellt och resultaten presenterades deskriptivt. Resultat: Grupp BB12 hade signifikant högre brotthållfasthet (2660 N) jämfört med EB7 som hade lägst medelvärde (1044 N) (p ≤ 0,05). Mellan övriga grupper fanns det ingen signifikant skillnad.Majoriteten av frakturerna skedde i det hängande ledet. Även totalfrakturer förekom. Slutsats: Utformning och placering av monolitiska 3-leds-broar i ett flerskiktat zirkoniamaterial påverkar brotthållfastheten och frakturtyp. Vid ökad konnektordimension kan placeringen vara i det övre skiktet i disken. Vid minskad konnektordimension kan placering vara i nedre skikt. Frakturerna sker vid det hängande ledet, och vid ökad konnektordimensionering och placering i nedre skikt sker totalfraktur

Background: The golden standard for single unit crowns has for long been porcelain fused to metal (PFM). However, demands for improved esthetic materials has driven the development of zirconia which has increased in popularity due to its eminent mechanical and esthetic properties. Long term follow-up of zirconia is lacking and no consensus regarding which luting agent to use has yet been established. Aim: The aim of the present study was to evaluate the longevity of single unit crowns in relation to luting cements used and to investigate if any shift in the choice of crown materials could be seen over time. Methods: A retrospective journal survey with inclusion criteria being patients treated with tooth supported single crowns at the students’ clinic at the Umea University School of Dentistry. Extracted data were focused on 8 factors regarding information about the patient and materials used in the crown treatment. Statistical analyses were made with GraphPad.com and Microsoft Excel 2010. Results: Core reinforced zirconia crowns luted with RelyX showed a statistically significant higher success rate (95%) compared to crowns luted with zinc oxide phosphate (60%) (p<0.05). The most common complications were loss of retention and chipping of the veneering porcelain. Conclusion: The choice of luting agent seems to be of importance for core reinforced zirconia crowns. No statistically significant difference in success rate could be seen for PFM and monolithic zirconia. A shift in the choice of crown material could be seen. Monolithic ZR had increased, while PFM and ZR core had decreased.

Background: Radiation therapy used for head and neck cancer patients cause many side effects in the oral cavity and above all affects the salivary glands. Complaint of dry mouth (xerostomia) and hyposalivation are common as well as swallowing difficulty (dysphagia) even after the cancer is remitted.  Aim: The aim of the study is to examine the correlation between hyposalivation and xerostomia in patients undergoing radiotherapy.   Methods: Six patients undergoing radiotherapy for head and neck cancer at Norrlands University Hospital participated in the study. A questionnaire regarding xerostomia was answered and a collection of stimulated as well as unstimulated saliva was taken.  Results: Regarding the stimulated salivary flowrate, one out six patients was below the limit of hyposalivation. Three out of six patients were below the limit of hyposalivation with reference to the unstimulated salivary output. The questionnaire regarding xerostomia showed that all patients experienced dry mouth symptoms to varying degrees. The questions concerning the dryness of the tongue and the amount of saliva in the mouth had the highest rating.  Conclusion: Regarding the patients that participated in this study, a correlation is shown between xerostomia and unstimulated salivary output. However, due to the lack of participants in the study, no firm conclusion can be drawn.