International Poster Journal of Dentistry and Oral Medicine, 01/2014

Background: In patients with severe atrophy in the premolar und molar region an augmentation with iliac crest bone is state of the art. Dental rehabilitation in patients using bisphosphonates is complicated since surgical procedures may initiate an osteonecrosis. The risk to develop an osteonecrosis can be evaluated by obtaining the CTX-blood-value which describes the bone turnover rate and inhibition of bone healing (normal CTX-value 400-700 pg/ml, low risk regarding osteonecrosis if CTX >150 pg/ml). Material and Methods: A 57-year old patient with a class-III anomaly, osteoporosis and being on oral bisphosphonates for approximately 10 years sought a dental rehabilitation and was referred with the intention of an augmentation because of the atrophy in the mandible up to the level of the mandibular nerve. The remaining front teeth were not worth keeping. A blood-CTX-value was obtained (133 pg/ml) indicating an increased risk therefore the bisphosphonate was paused. After the bone turnover recovered (CTX-value 148 pg/ml) surgery was preformed. The remaining teeth were extracted and 4 implants were placed according to the Malo principle. Results: The teeth were extracted and 4 Astra Tech Osseospeed implants were inserted and covered with healing abutments. A post-operative bleeding induced a disturbed wound healing resul-ting in exposed bone (CTX-value 163 pg/ml). Only antibiotics and chlorhexidin mouthrinse were prescribed. Another 2 weeks later there was no more sign of infection and exposed bone. A bar was inserted that is wearing a denture. Conclusion: Implant surgery can be performed in patients taking oral bisphosphonates especially after a drug-holiday at a lower risk due to the recovered bone turnover and bone augmentations can be avoided using the Malo concept in this case using 4 Astra Osseospeed implants. Placing implants is a less invasive operation compared to bone augmentation and might become a treatment option in some bisphosphonate patients. Keywords: Bisphosphonate, Bisphosphonate associated osteonecrosis of the jaws, implant, CTX

INTRODUCTION: VEGF-SNPs are associated with the incidence of oral squamous cell carcinoma (OSCC). An impact of VEGF-SNPs on prognosis of OSCC patients has not been proven. Therefore, correlations between prognostic parameters of OSCC patients and f VEGF-SNPs were determined. MATERIALS AND METHODS: In a retrospective long- term study, in 120 OSCC patients that underwent curative resections, five VEGF-SNPs (1154 G/A, +405 G/C, +936 C/T, 2578 C/A, and 460 C/T) were analyzed. Associations between SNPs and prognosis (incidence of local recurrent disease, second cancer, metastases, death, total disease-free survival) were examined. RESULTS: After a mean follow-up time of 57.6 months, 32 patients had local recurrences; 15 patients had second cancer, 15 patients metastases, and 23 patients died. The mean disease-free survival was 43 months. A significant increased incidence of OSCC in smokers with the VEGF 2578 A/C and 460 C/T SNP was seen (each P 0.015). In univariate analysis, patients with advanced OSCCs (T > 2 or N > 0) together with the 1154 A/A allele had a significant worse survival and a worse disease- free survival (both P 0.04). The same was seen for the +405 G/G SNP (both P = 0.002). In multivariate analysis, only the negative influence of the +405 G/G SNP on survival in advanced OSCCs (T > 2) could be confirmed (P = 0.002). DISCUSSION: Possible reciprocal interactions between smoking and VEGF-SNP function were observed. Multi- variate analysis confirmed the VEGF +405 G/G genotype to be associated with poor survival in advanced OSCCs; a further use of this haplotype as biomarker has to be discussed. Keywords: Oral Squamous Cell Carcinoma, VEGF Mutation, Single Nucleotide Polymorphisms, Long-term Prognosis

Introduction: 3D planning software and its application to CAD/CAM wafers for mandibular-maxillary orthognathic surgery has evolved over the last decade. The aim of this study is (a) to give an overview over the current status in literatur concerning three-dimensional planning of mandibular-maxillary orthognathic surgery, (b) the clinical application of these results and based on this (c) the developement of a 3D-planning protocall for mandibular-maxillary orthognathic surgery. Methods: Literature research was done over NCBI PubMed. Mandibular-maxillary orthognathic surgery were planned using Simplant Pro 2011 OMS (Materialise, Leuven, Belgien). Parallel conventional planning using 2D-cephalometry and plaster cast model surgery was performed. Based on this clinical expierence a planning protocol for three-dimensional planning has been developed. Results: Literatur research showed 9 patient studies using 3D-planning and CAD/CAM surgical wafers for mandibular-maxillary orthognathic surgery. 2 studies based completely in planning and performance on a 3D-concept, 1 study used CAD/CAM wafers produced with a 3D software based on 2D-cephalometric data, 1 study compared 2D- and 3D-planning for mandibular-maxillary orthognathic surgery with a surgical rating system and 4 studies compared conventional produced surgical wafers with 3D based CAD/CAM wafers on patients plaster cast models. Clinical application showed similar fitting for CAD/CAM wafers in the preoperative fitting as the conventional produced wafers. The 3D-planning protocol won from these findings is showed in graphics. Discussion: 3D-planning mandibular-maxillary orthognathic surgery is in a usable phase. Planning is easy and a accurate method for the therapie of craniofacial deformities. Clinical application seems to have similar results as conventional planning. A clinical study with an appropriate number of patients is planned for further evaluation. Keywords: 3D planning, dysgnathia, CAD/CAM surgical wafers

The prevalence of caries on the proximal tooth surface is high and the interdental location of the lesion a challenging site for treatment. In this study patients with early proximal caries (E1 and E2) are treated with the regenerative product Curodont™ Repair. It contains P11-4, a self-assembling-peptide (SAP), that is applied as a solution onto the lesion surface. P11-4 then diffuses into the subsurface body of the early carious lesion where it forms a 3-D fibril network. In the process of a few months Ca2+ and PO43- ions, excessively present in the patient's saliva, attach to the nucleation sites of the P11-4-network and induce formation of de novo hydroxyapatite (HA) crystals [1]. The aim of the present study is to evaluate the efficacy of Curodont™ Repair in respect to regenerate enamel in patients with early proximal caries. Keywords: carious lesion, regeneration, hydroxyapatite, remineralisation

Data on whether periodontal therapy affects serum lipid levels are inconclusive. This study was to explore the relationship between periodontal diseases and serum lipid level, investigating its link to various systemic diseases related to hyperlipidemia. Thirty systemically healthy patients with periodontal disease were recruited for the study. All subjects underwent oral examination and their clinical periodontal parameters were recorded. Five milliliters of fasting venous blood sample was drawn and tested for the systemic levels of total cholesterol, triglyceride (TG), high-density lipoprotein (HDL) and low-density lipoprotein (LDL). The results revealed the mean lipid serum levels (mmol/L) at the baseline are 4.9 (1.0), 1.2 (0.48), 1.6 (0.58), and 2.8 (0.83) for the total cholesterol, TG, HDL and LDL respectively. There is a positive correlation between the lipid serum levels and clinical periodontal parameters represented by the percentage of sites with the presence of plaque, mean clinical attachment loss and the percentage of sites with moderate pocket depth, but this correlation failed to reach the statistical significance. This study demonstrated that patients with periodontal disease have no significant correlation with serum lipid levels (p>0.05), however subjects with increased level of bleeding on probing reflected significant non-desirable level of HDL (p = 0.006). Keywords: Periodontal diseases, serum lipid, high-density lipoprotein

Background: E-learning has been recognized during recent years as an essential tool to improve dental education; however, the best approach to implementing computer-assisted learning, as well as avoiding information overload are topics of ongoing discussion. Since 2009 our department has been developing a modular interactive e-learning tool (ILKUM) focussing on the medical curriculum (MC) to improve medical education. It includes small e-modules with structured descriptions of diseases and operative techniques mentioned in the MC supported by additional clinical cases, short video sequences, and scientific articles. Additionally updates are announced over Facebook. Objective: Objective was to analyse the overall acceptance of ILKUM. The percentage of students being able to use e-learning (possession of a computer/ access to internet) and those actually using it was evaluated. Additionally, we evaluated ILKUM as a useful learning tool and the potential demand for continuous upgrades. Furthermore, e-learning self-testing scores were analyzed and correlated with the real exam results. Methods: One student cohort (n: 68 ± 14) was followed in a longitudinal study from the implementation of ILKUM until the final exam (04/2009 - 10/2010). Acceptance of ILKUM was evaluated by an anonymous questionnaire. The overall results were correlated to the average e-learning self-testing results of the students. Statistics were restricted to descriptive analyses only. Results: By the end of 2010, all students had access to a fast internet connection. 90% of the students possessed either a laptop or a netbook. Only 10% had a non-portable desktop computer. The proportion of students using the internet as an information source for academic research constantly increased. The proportion of students who thought ILKUM was a useful tool increased from 84% in 2009 to 90% in 2010. About 90% of all students asked for ongoing ILKUM updates with more content. Positive feedback regarding self-testing increased from 62% in 2009 to 78% in 2010. The proportion of correctly answered exam questions correlated with self-testing feedback, increasing from 51 in 2009 to 73% in 2010. The average monthly account on Facebook was about 6600 clicks. Conclusions: Parallel to the development of our e-learning portal, the proportion of students using the internet as a learning tool constantly rose. Furthermore, there was consistent demand for upgrades to our e-learning tool, which was reflected in the rising number of students preferring e-learning and self-testing. This correlated with an improvement in exam results. The broad acceptance and demand for the new e-learning database among students reflect the importance of developing such systems. Next steps include structural modifications to the database in close cooperation with the students, focussing on the expansion of interactive self-testing. The newly designed e-learning software has positively contributed to the common interest of students and teachers by supporting modern medical education. The ILKUM concept could potentially become a state of the art "level based" modular e-learning tool. Keywords: e-learning, dental education

Introduction: Prosthetic abutments with reduced width in relation to the implant diameter (platform switching, PS) seems to have potential to reduce crestal bone loss around dental implants. There are limited studies comparing this concept with standard abutments in the same implant system. In accordance to this, the study aimed to evaluate crestal bone level of the same implants in a definite indication restored with PS and with standard abutments (SA). Materials and Methods: In a prospective randomized international multicenter study, 68 patients were provided with 163 implants (Camlog® Screw line) and restored with PS (n=83) as well as with SA (n=80) in the posterior mandible. Indications were: ≥2 adjacent missing teeth, natural tooth mesial to proximal implant site, full opposition dentition, implants placed at least 6 weeks post extraction and no bone augmentation. Primary objective was a comparison of changes in crestal bone levels (fig. 1) between the groups. We will report the first results of the implants after 1 and 2 years. Results: After a total follow-up of 2 years, in the PS group a mean bone gain of 0.15 mm was recorded between the time of prosthesis placement and 12-months post-loading and 0.22 mm after 24-months post-loading (fig. 2). In comparison, a bone loss of 0.09 mm and 0.27 mm was measured in the SA group for the one and two-years loading period. For both time points the difference is significant (p=0.005 and 0.004; fig. 3,4 and 5). The total implant survival was 98.2%, 3 implants were lost. Discussion: the PS concept seems to be suitable in order to limit crestal resorption and to preserve peri-implant bone levels. Keywords: Dental Implant, Camlog, Platform Switch, Crestal Bone Resorption, peri-implant Bone Level

Statement of purpose: The aim of the present study was to compare the condylar guidance angulations obtained from protrusive records, orthopantomographic tracings and 3- dimensional computed tomographic angulations in edentulous patients. Materials and Methods: Thirty edentulous patients were selected according to the set inclusion criteria. Protrusive records were made using polyether bite registration paste.(group 1). An OPG (group 2) and 3-D CBCT tracings (group 3) were done for each patient. Angulation was measured using the guidelines given by Ilan gilboa et al. The values obtained in the three groups were tabulated and compared using Kruskul-Wallis test, Wilcoxon signed rank sum test and Mann-Whitney 'U' test. Results: The mean values obtained in group 1 were 34.3625 and 35.6625 on the right and left sides respectively. Group 2 showed mean values of 32 and 33.3 whereas group 3 showed mean values of 36 and 37 on the right and left sides respectively. P value was 0.302 on the right side and 0.191 on the left side which were not significant. Comparison of the right and left side values to each other showed no significance statistically. (p 0.01) Conclusion: Within the limitations of this pilot study OPG and Protrusive records are both reliable guides for recording condylar guidance inclinations Clinical implication: Interocclusal records for recording the condylar guidance in edentulous patients has many in-accuracies incorporated (upto 30 degrees) due to resiliency of the tissues . Ortho pantomogram may be used to as a reliable guide in setting the condylar guidance in semi-adjustable articulators. Keywords: Condylar guidance, Protrusive records, Conebeam CT, Orthopantomograph, Condylar angulation, Programming articulator

The formation of secondary dentine leads to an age-related decrease of the pulp cavity volume. Hence, the volume of the pulp cavity relative to the volume of its tooth could be useful for dental age estimation based on three-dimensional cone-beam computed tomography (CBCT) x-ray images. A sample of 69 single-rooted teeth from 26 patients aged 19-89 years was collected for this pilot study. The teeth had no caries or signs of restaurative dental treatment and showed unimpaired root apices. All teeth were scanned by a CBCT (Accuitomo, J. Morita, Kyoto, Japan) using an clearly defined experimental set up ensuring a uniform exposure setting, determined by pretrials.Using threshold segmentation, three methods for segmentation and volume measurement of enamel, dentine and pulp cavity were tested. Tooth and pulp volumes and volume ratios were calculated for the whole tooth, the root region and at four levels. The relationship between the volume ratios and age was determined by Pearson's correlation coefficient (r), the accuracy of age estimation by the determination coefficient R². The Wilcoxon sign rank test was employed to measure the intraobserver error of manual segmentation. From the three segmentation methods, the manual non-reconstructable method showed the highest coefficient of determination (R² = 0,663). There were no statistically significant intraobserver differences. From the specific volume ratios, the highest correlation was observed for the coronal third of the root (R² = 0,621). The results provide support for the use of tooth-pulp volume measurements from clinically acquired CBCT images for age estimation. Keywords: dental age estimation, pulp-tooth-volume ratio, secondary dentine/formation, forensic dentistry, cone-beam computed tomography, VoXim

Natural remineralization of tooth material in demineralized small subsurface lesions provides a challenging purpose. Currently early dental caries are mainly treated by mechanical techniques, like dental fillings or tooth extraction, or by applying protective barriers to the tooth surface, like varnished, containing e.g. fluoride. As a result research is concerned with non-invasive regeneration methods of early caries in enamel/ white spot lesions. The scientific breakthrough was achieved by applying a self-assembling peptide (SAP) to the cavities. The fully synthetic peptide forms a 3D supramolecular network in situ and is assumed to trigger nucleation of calcium phosphate nanocrystals, resulting in a biomimetic mineralization and therefore a regeneration of demineralized cavities In this project, the diffusion, assembly and remineralization process of the peptide P11-4 were studied in artificially demineralized cavities of human teeth. Keywords: caries lesion, Remineralization, Self-assembling peptide, Enamel, Non-Invasive

The investigation of a non-invasive, biomimetic mineralisation method of sub-surface carious lesions/ early caries lesions in tooth enamel is the field of attention in this project. P11-4 is a short peptide, which self-assembles in a supramolecular 3D network after applying in the carious lesion. The hypothesis is that this self-assembled structure triggers nucleation of de-novo hydroxyapatite nanocrystals and consequently results in lesion-remineralisation. Because of the limited availability and difficult access to usable human teeth and their great structural variability and composition a bioceramic tooth model will help to standardize the test systems and support the comparability of results. Keywords: Remineralisation, carious lesion, self-assembled peptide, artificial tooth model, hydroxyapatite