International Poster Journal of Dentistry and Oral Medicine, 01/2008

Aims: Overview of the dental education system at the Medical University of Innsbruck, Austria. The performance of the established theoretical and practical dental admission test is presented. The essential requirements for taking part in the admission test and the operation procedure are explained in details. The evaluation and assesment of the theoretical and practical dental admission test are discussed and the criteria for selection are defined. The aim of this investigation was to examine the clinical relevance of the dental admission test for the selection of dental students in Austria. by examining the relationship between the results of the dental admission test and the student's performance in the first clinical year. Materials and Methods:A total of 5 complete classes of dental students (97: 41 female, 56 male) were examined in the study. The dental admission test contained 5 practical tests to assess the fine motor skills and spatial ability. The following practical tests were used: waxing test, bending wire test, smoothing and polishing the surface of an acrylic block, milling a defined line with a diamond bur and drilling parallel wholes. The results of the students in the dental admission test were compared with the grades in their first clinical year. Results:The results of the dental admission test showed correltion with the performance of the students in the first clinical year. There was only one dropout after the student during the first clinical year. Conclusions:The current selection progress seems to be a good predictor for the success of dental students in Austria in the first clinical year. Keywords: Dental admission test, dental education, academic qualifications

Number of patients with hypersensivities on dental materials increases continously. One of the most important allergens is benzoyl peroxide (BPO). BPO is part of the promoting system of acrylic denture materials. Aim of this study was to describe the BPO contents of denture materials after storage and different chemical treatments. 3 hot-curing acrylic resins, 2 self-curing acrylic resins and 1 microwave-curing denture material were investigated. BPO was measured in the polymer delivered by the manufacturer, after polymerization as recommended by the manufacturers, after extended polymerization (1 and 2h), after storage in water (aqua dest.) for 8 days, after storage in saliva (Fusayama,1963) for 8 days, after storage of 48h in KMnO4, alcohol and (NH4)2Fe(SO4)2. Indirect jodometry was used to detect BPO. BPO was found in all acrylic resins. However, there were significant differences between the resins (polymer 0,13 - 1,2 weight %, cured products 0,05 - 0,32 weight %) and differences between the specific treatments and storage procedures. The smallest effect on BPO showed (NH4)2Fe(SO4)2 after 48h (reduction 0 - 27 %). The strongest effect occured after extended polymerization for 2h (reduction 63 - 95 %). No reduction of BPO was seen after 8 days storage in water and artificial saliva. The microwave-curing material contented the lowest BPO-level of all materials. Under intraoral conditions it is unlikely that BPO is released from acrylic resin denture base materials. BPO in denture base materials can be reduced by extended polymerization. Keywords: allergy, denture base materials, acrylic resin, BPO, MMA

There is a growing body of evidence on the association of periodontal pathogens present in periodontal environment and periodontal pathologies in adults while the so far existing data on periodontal microbiology of infants and children have been limited. Aim: The aim of this study was to identify the known periodontal pathogens in infants with ECC and children cared of by the Teaching Hospital in the city of Brno. Methods: Altogether 37 infants aged 2-4 years and 96 children (mean age 14.57, SE=0.84) were involved in screening periodontal pathogens in both bleeding and healthy gingival sites. Material from gingival sites was absorbed to endodontic paper points and processed in ParoCheck® kits (Greiner Bio-one GmBH, D). Bacterial species were identified by means of hybridization in situ method using 16S rRNA fragment and highly conserved primer labelled by fluorophore (Cy5). Hybridized samples were labelled by strain specific DNA-sondes and identified according to ParoCheck®Report-Software. Findings in gingival bleeding and healthy sites were compared (chí² test; P = 0.05). Results: Infants - frequency in bleeding gingival sites (%): A. actinomycetemcomitans (AA) 32.4, P. intermedia (PI) 5.4, F. nucleatum (FN) 54.1, T. denticola (TD) 10.8, T. forsythensis (TF) 2.7, P. nigrescens (PN) 5.4, all significantly more often than in healthy sites (P Keywords: gingivitis, pedodontics, ELSPAC, ECC, periodontal pathogens

Introduction: Considering the problem of stabilization of removable prostheses dental mag-netic systems (DMS) offer an alternative to traditional methods. Regarding the technological advantages during the last years DMS have been developed that promise an increase of retentive force by small type of construction. Two physical principles are used: mono-systems with open (MO) and with closed magnetic loops (MC). Furthermore, there are 3 de-signs of keepers for retained roots: prefabricated dowelretained keepers (PK), individual caps of magnetic alloys (IC) and preformed magnets cast on caps of conventional alloys (CC).The aim of this study was to evaluate and to compare the mechanical performance of contemporary DMS used on tooth roots. Methods: 11 different DMS were standardized tested for maximal retentive force and dynamical development during draw off in an adjusted computer-navigated test-machine (v=20mm/s, s=40mm). From IC/CC-systems root-attachments were produced according to the manufacturers' instructions. 5 specimens of each product were investigated. Denture-magnets and the corresponding keepers or caps were fixed in an individual non-magnetic construction. The results were descriptively and statistically analysed (H-/U-Test). The findings were compared with the manufacturers' statements. Results: The maximum retentive force ranged from 6,58N to 1,38N. Compared to the manufacturers' information significantly lower initial retention forces were found in all specimens (p0.05). MC showed the highest and MO the lowest initial retention forces. This relation changed with an increasing gap between root and magnet. Considering the different heights and diameters of the products no significant differences were found among the PK-, IC- and CC-systems. Conclusion: In all products maximum retention forces were found no-table under the manufacturers' information. There were significant differences between the clinically important draw-off forces, whereas no differences between the rootkeeper-designs were found. These results could be useful by individual choice of DMS on retained tooth roots. Keywords: magnets, keeper, retention, overdentures, attachments

Background: Although more than 100 million passengers, mostly from industrialised nations, have taken a cruise since 1980 on a growing fleet of cruise ships with ever increasing numbers of crew, the majority of whom come from developing nations, little is known about oral health of these two distinctly different populations. Methods: In a retrospective, descriptive epidemiologic study design the routine documentation of all dental treatment provided during two months at sea in 2006 was analysed after the voyage. Subjects were n = 57 passengers (3.5 % of 1619) with a mean age of 71 (± 9.8) years and n = 56 crew (5.6 % of 999) with a mean age of 37 (± 12.0) years. Age, gender, nationality, number of natural teeth and implants were extracted. The prosthetic status was described by recording the number of teeth replaced by fixed prosthesis and number of teeth replaced by removable prosthesis. Oral health-related quality of life (OHRQoL) was measured using the 14-item Oral Health Impact Profile (OHIP-14) and characterised by the OHIP sum score. Results: Women attended for treatment more often than men. Passengers had a mean number of 20 natural teeth plus substantial fixed and removable prosthodontics. Crew had a mean of 26 teeth. British crew and Australian passengers attended the dental service above average. Crew tended to have a higher average OHIP-14 sum score than passengers indicating an increased rate of perceived problems. Emergency patients from both crew and passengers have a higher sum score than patients attending for routine treatment. Differences seen between the two groups are not exclusively attributable to the age factor but represent differing backgrounds in home countries. Socioeconomic factors serve to explain the high standard of prosthetic care in passengers. Crew in general present with less sophisticated prosthetic devices. This is in line with their different socioeconomic status and origin from developing countries. Salary of the individual crew member together with the level of dental fees aboard in comparison to treatment costs in home countries may explain some of the differences in attendance. The ease of access to quality dental care may explain the relatively low level of perceived problems as characterised by oral health-related quality of life scores. Conclusion: Passengers have enjoyed high standards of prosthetic care in the past and will expect a similarly high standard from ship based facilities. The dental officer aboard has to be prepared to care for very varied diagnostic and treatment needs. Keywords: Oral health, Maritime medicine, Cruise medicine, OHIP, Gerodontology

Objectives: The aim of this study was to evaluate the influence of different restoration materials on demineralization on irradiated enamel and dentin. Methods: Thirty-two freshly extracted human third molars without caries were used. The teeth were assigned to four groups (n=8). Over the whole experimental period specimen were stored in 0.9% saline. All teeth were prepared with class II-cavities (mesial dentin, distal enamel). After preparation cavities were filled with four different materials (composite resin, amalgam, glass ceramic inlays and gold inlays). All teeth were bisected along their long axis in the middle of the fillings. One half of each tooth was irradiated with 60 Gy (2 Gy/ day for six weeks), the other half remained non-irradiated. All specimens were demineralized for 6 days with acidified gel (HEC, pH 4.8, 37 degrees C). From each tooth, two dentinal slabs were cut. The depth of the demineralized areas was determined using a polarized light microscope. Results: In all specimens lesion depth could be recorded. Significant higher lesion depths were found for the dentin and enamel in group AF+ (*p

Purpose: Implant success and survival data indicates that altered loading protocols may exert only limited effects on treatment outcomes and are rarely associated with an increase in negative observations. Early functional loading of unsplinted implants with attachment overdentures may become more widespread as a simplified and efficient treatment option for edentulous patients. However, clinical studies are required to evaluate the success of this approach. This study was designed to evaluate early loading (healing time less than 3-months) of unsplinted dental implants characterized by a chemically modified surface, when used to support overdentures in the edentulous jaw. Materials and Methods: Eleven patients with edentulous mandibles and/or maxillas received between 2 and 4 solid screw titanium implants (n=44). The implants were characterized by a chemically modified surface (SLActive, Straumann Dental Implant-System, Straumann AG, Basel, Switzerland). Mean healing time was 52 days subsequent to implant placement. Locator abutments (Straumann Dental Implant System) were positioned (n=32 mandible and n=12 maxilla) and torqued to 35Ncm. 34 implants within the study group were loaded earlier than 6 weeks after implant placement. Locator attachments were placed on each abutment and then picked up in the patients denture. Radiographs were taken and clinical assessments were made at loading and after 3 months in function. Results and Conclusions: A total of 44 SLActive implants were placed as part of the study. Throughout the period of follow-up no implants were lost or considered failures. The implant survival and success rates were therefore 100% for this preliminary evaluation. All patients are functioning with an attachment retained implant supported prosthesis. To date no complications have been recorded with regard to denture function, denture esthetics or periimplant tissue health. To date no evidence of bone loss associated with the healed or loaded implants exists. No negative observations were recorded in the group of implants loaded earlier than 6 weeks.Within the limitations of this pilot study preliminary results suggest that the early loading of unsplinted, chemically modified surface implants, results in implant and prosthesis survival rates comparable with existing literature when considering treatment of the edentulous mandible. Keywords: Early loading, implant surface, edentulous

To be able to properly evaluate the risk and the benefit of using commercially available bone substitutes, the material has to be tested both clinically and biologically. One of the main investigation criteria discussed in the literature is the new bone formation within human biopsies obtained at the time of implant placement. As new bone formation is regarded as a direct measure of osteoconductivity, leading to the osseointegration of the dental implant, it is directly related to the success of the implantation. Bio-Oss® has been evaluated in more than 500 Publications of which 45 present histological and histomorphometric data of human specimen. In 25 out of the 45 publication the individual data for each biopsy was reported and used to perform a meta-analysis. A total of 341 biopsies were included. The here presented data cover bone growth rates on Bio-Oss® in different indications and investigate the benefit of the addition of autogenous bone. Keywords: Bio-Oss, bone augmentation, meta-analysis

Introduction: Gunshot wounds commonly result in extensive tissue damage with disruption of soft tissue. Immediate treatment under difficult conditions on site often leads to poor clinical outcome. Case report: We report on a 81-year-old patient who suffered from a shell-splinter injury during the Second World War in 1944. On clinical inspection cicatrices in the left nasolabial groove, the chin and the left side of the neck were observed. Moreover, an unincisive vermilion of the lower lip and high tonicity of the face muscles was noticed. The intraoral tegument in the lower jaw was reconstructed by means of a split-thickness skin graft from the abdominal wall. Radiography did not reveal any metallic fragments or defects of the bone. This case report focuses on soft tissue reconstruction as estimated on the basis of scars. Discussion: Local flaps provide good aesthetic and functional results after facial skin reconstructions. Alternatively, skin microsurgery grafts and skin extension closures may serve as surgical procedures for contraindications of local flaps.

Introduction: Considering the problem of stabilization of removable prostheses dental mag-netic systems (DMS) offer an alternative to traditional methods. Regarding the technological advantages during the last years DMS have been developed that promise an increase of retentive force by small type of construction. Two physical principles are used: mono-systems with open (MO) and with closed magnetic loops (MC). Furthermore, there are 3 de-signs of keepers for retained roots: prefabricated dowelretained keepers (PK), individual caps of magnetic alloys (IC) and preformed magnets cast on caps of conventional alloys (CC).The aim of this study was to evaluate and to compare the mechanical performance of contemporary DMS used on tooth roots. Methods: 11 different DMS were standardized tested for maximal retentive force and dynamical development during draw off in an adjusted computer-navigated test-machine (v=20mm/s, s=40mm). From IC/CC-systems root-attachments were produced according to the manufacturers' instructions. 5 specimens of each product were investigated. Denture-magnets and the corresponding keepers or caps were fixed in an individual non-magnetic construction. The results were descriptively and statistically analysed (H-/U-Test). The findings were compared with the manufacturers' statements. Results: The maximum retentive force ranged from 6,58N to 1,38N. Compared to the manufacturers' information significantly lower initial retention forces were found in all specimens (p0.05). MC showed the highest and MO the lowest initial retention forces. This relation changed with an increasing gap between root and magnet. Considering the different heights and diameters of the products no significant differences were found among the PK-, IC- and CC-systems. Conclusion: In all products maximum retention forces were found no-table under the manufacturers' information. There were significant differences between the clinically important draw-off forces, whereas no differences between the rootkeeper-designs were found. These results could be useful by individual choice of DMS on retained tooth roots. Keywords: magnets, keeper, retention, overdentures, attachments