International Poster Journal of Dentistry and Oral Medicine, 03/2012

Objectives: To investigate the effect of erosion / remineralisation challenges on microtensile bond strength (mTBS) of two dentin adhesives (Optibond FL, Futurabond M) in vitro. Material and Methods: 150 extracted third molars were included. The specimens were randomly assigned to one of the five challenges of thirty samples each: G-1: control; groups G-2/-3: 10-minute immersion 4x/day in Sprite Zero for 7 days; G-4/-5: 5-minute immersion 6x/day in citric acid for 10 days. In G-3/G-5 the first and the last erosive challenge was followed by 2-minute remineralisation challenge in elmex EROSION PROTECTION dental rinse. Between the erosive/remineralisation challenges, the specimens were immersed in artificial saliva. Subsequently, the dentin specimens were restored with either Optibond/Grandio (O) or Futurabond/Grandio (F). Results: Following mTBS were evaluated (in MPa): G1-O: 25.46 (±5.02); G2-O: 18.59 (± 4.77), G3-O: 22.94 (± 3.87), G4-O: 11.02 (±2.62); G5-O: 16.00 (±3.53); G1-F: 20.91 (±4.53); G2-F: 15.20 (±3.62); G3-F: 17.04 (± 5.32); G4-F: 5.05 (±1.03); G5-F: 11.71 (±2.24). Statistical analysis showed a significant influence of the used adhesive and the challenge on mTBS (p0.001, ANOVA). Erosive challenges resulted in a significant reduction of mTBS compared to the untreated controls. Remineralisation with elmex dental rinse increased mTBS significantly in G-5 compared to G-4 (p0.05, Tukey's test). Conclusions: Erosion affected the mTBS of both adhesives in vitro. Remineralisation with elmex dental rinse might be a solution to increase mTBS of adhesives on eroded dentin. Clinical relevance: Adhesive fillings are commonly used to restore eroded dentin. Schlagwörter: erosion, remineralisation, microtensile bond strength, dentin adhesives

Young children have, unfortunately, the proclivity for running with objects holding in their mouth and falling. Then it comes to penetrating injuries in the oral cavity. Initial symptoms are rather bland, and often the small wounds heal uneventful without surgical intervention. In the primary therapy of these children also the question of any remaining foreign body in the wound comes up. An 11-month-old boy fell at home while crawling with a pen in his mouth. On examination the child was awake, quiet, and had no dyspnoea, cough, or even neurological impairment. The approximately 1.5 cm long wound in the soft palate did not bleed. Since there was no suspicion of a foreign body, surgical repair was renounced, and follow-up consultation for the next day was arranged. At home, the mother detected, that the 1 cm long metal tip of the ballpoint pen lacked. Under general anaesthesia the foreign body was found and removed endoscopic assisted from the atlanto-occipital area. In children with penetrating wounds of the soft palate it must to be alert also to an unexpected remaining foreign body in the posterior pharyngeal wall. In the case report it was initially not supposed, that the metal tip of a ballpoint pen remained in the wound. Therefore, we recommend looking at the object of injury in order to initiate further diagnostics (CT, MRI) to search for a foreign body. Schlagwörter: penetrating injury, oral cavity, foreign body

Introduction: Tongue has been considered as a good reflection of systemic disease since Hippocrates time. However, localized, non-systemic tongue lesions are more commonly encountered. Materials and methods: A total of 200 walked in patients (89 males, 112 females, aged 10-59 years, mean age 34.2) were examined during the period of July - September 2009 in Kementah Dental Centre. Results: Tongue lesions was found in 90 of the 200 examined subjects with 13 (6.5%) subjects presented with more than one lesions, 4 have coated and fissured tongue; 4 with coated and crenation tongue; 2 presented with crenation tongue and partial angkyloglossia; 2 with fissured and crenation tongue, and one with fissured and partial angkyloglossia. Coated tongue was the commonest tongue lesion found with a prevalence of 45%, followed by crenation tongue (30%), partial ankyloglossia (21%), fissured tongue (18 %), geographic tongue (7%), and hairy tongue (2%). 43 (21.5%) of the subjects were smokers. Only 13 (6.5%) of the subjects were taking medications, mostly oral contraceptive pills. Conclusions: The prevalence of tongue lesions in this survey is 45% with coated tongue as the commonest which in turn were seen mostly in smokers (73% of male coated tongue were smokers). In this study. tongue lesion was more common in men (55% in male compared to 35% in female). No specific tongue lesion was seen in patients who are taking medications due to small sample size. Schlagwörter: tongue lesions, prevalence, outpatients

Objectives: The aim of this study was to evaluate the influence of different restoration materials on demineralization on irradiated dentin. Methods: 55 freshly extracted human third molars without caries were used. Over the whole experimental period specimen were stored in 0.9% saline. Dentin disks were prepared. The 55 disks were assigned to five groups (n=11) including a positive and negative control. After preparation in three groups occlusal restorations with different materials (amalgam, base metal alloy, titanium alloy) were fabricated. Four groups were irradiated with 60 Gy (2 Gy/ day for six weeks), the negative control group remained non-irradiated. All specimens were demineralized for 14 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. Statistical analysis showed a significant influence of irradiation and the used material (p 0.001, ANOVA). Between both control groups (C, C60) no significant differences could be detected (p> 0.05, Tukey test). Between the controls and the restored groups significantly increased lesion depths could be observed (p 0.05, Tukey test). Pairwise comparison between the three materials showed no significant differences (p> 0.05, Tukey test). Conclusion: Irradiated Dentin with metal restorations showed the significantly highest lesion depths after initial demineralization by acidified gel compared to the control groups. The different metal materials had no significant impact on artificial dentin demineralization. Schlagwörter: restorative materials, irradiation, demineralization

Introduction: The loss of facial nerve (FN) function is associated with some negative accompanying effects on the patient. Besides the functional problems, the facial asymmetry and the inexpressiveness severely impair the psychosocial impact of the patient. Therefore a fast FN recovery after a surgical trauma is very important for the patient. Until now different treatment options have been discussed to accelerate the recovery of the FN function, but none of the described treatments have proved to be successful. Encouraged by animal and promising results of different clinical studies by neurosurgical departments, an "off-label" use of nimodipine (NimotopS®, Bayer AG, Leverkusen, Germany) was performed to expedite the process of FN recovery after postoperative peripheral nerve paresis. Methods: Thirteen patients (n=13) suffering from a moderate (1/13) up to a severe (12/13) peripheral FN paresis after maxillofacial surgery were treated with orally administered nimodipine. The anatomical main course of the FN was preserved in all patients with a 2nd to 3rd degree of Sunderland-injury. After no evidence of a spontaneous regeneration had shown, an oral medication with nimodipine was started as an "off-label" use. Results: An improvement of the FN function correlated to the start of the vasoactive medication and as a consequence a recovery of the FN function up to House-Brackmann (HB) grade I-II was ascertained in all observed patients within a period of two months after the beginning of treatment (p=0.00027). Conclusions: The clinical observations in these patients suggest a positive effect of nimodipine on the acceleration of peripheral FN regeneration after a surgically caused trauma. The results of this pilot-study are very promising. A prospective study with a bigger number of patients is planned to approve the beneficial effect of nimodipine on the peripheral FN in maxillofacial or otorhinolaryngological surgery. Schlagwörter: regeneration N. fazialis, nimodipine

Estimation of salivary flow rate and epithelial cells present in unstimulated and stimulated saliva samples of ten male individuals with no known disease as per our knowledge has been analysed. The salivary flow rate,the exfoliated epithelial cells present, bacterial colonies and inflammatory component in stimulated and unstimulated saliva was analysed. Schlagwörter: saliva, salivary flow rate, stimulated, unstimulated, epithelial cells

Aims: Is it practically possible to implement EBM with problem-oriented questions into pregraduated dentistry education? Materials and Methods: Within a voluntary tutorial the participating dentistry students were offered a EBM basic course. Followed by basic EBM concept teaching, a PICO question was explored according to EMB-principles (PRISMA-protocol), which the students decided on themselves. The students examined the problem under scientific aspects, to see if carrying sterile gloves (compared to not using sterile gloves) reduces the postoperative infection rate during simple surgical operations of the oral cavity. Results: The systematic review was conducted by using predefined search words in PubMed and Cochrane Library as well as a manual search in scientific dental journals. The selection by the inclusion criterion (prospectively-designed studies) resulted in 4 studies with altogether 1219 patients. There was no difference in the post postoperative infection rate. The results were discussed with the students and the respective studies weighted. The students presented the results of the their work on the german national dentistry congress as a poster. Also the review of the corresponding article is in final stage of a successful completion. Conclusions: EBM is considered as a important part of the dentistry education, but its implication into the teaching programs is often not realized. Our project could point out the successful application of EBM into dentistry training. This also resulted in a training in scientific presentations and publication. By using iPads in follow-up projects an advancement of small tutorials in the sense "of the Blended Learning" is achieved. Furthermore the project is extended throughout the University Medical Center Mainz to intensify the networking between methodical-scientific and clinical-practical training. Therefore a postgraduated training ("Train the Teacher") is in preparation. Schlagwörter: EBM, small group instruction, zahnärztliche Ausbildung, Lehrforschung

Objective: Periodontitis as a bacterially induced chronic inflammatory disease is triggered by specific host dependent immune response. The expression of the genes involved in inflammatory processes is influenced among others by genetic and epigenetic modifications. Moreover, many risk factors associated with periodontitis, including bacterial occurrence, smoking, or diabetes, are known to induce epigenetic changes. Methods: In order to evaluate the impact of epigenetic modification on regulation of inflammatory genes in periodontitis we established and validated a Combined Bisulfite Restriction Analysis (COBRA) for assessing CpG methylation of TNFa-gene on position c.-668. After bisulfite conversion (EpiTect Bisulfite Kit, Qiagen) specific seminested PCRs were performed. For COBRA restriction enzyme HinfI was used. As positive and negative controls methylated and non-methylated converted DNA (Qiagen) were used. Patients: 24 patients (18 patients with severe chronic or aggressive periodontitis: mean age: 47.5+9.7y, 13males; 6 periodontitisfree healthy controls: mean age: 41.8+6.6y, 4 males) were included in the study. From 12 periodontitis patients the methylation status was determined in gingival tissue. The methylation pattern of 6 controls and 6 periodontitis patients was assessed in venous blood. Results: In gingival tissue there was a significant reduction of CpG methylation in TNFa-promoter compared with venous blood (61% vs. 100%, p0.001) possibly leading to an increase in TNFa-gene expression. However, in venous blood there was no difference in methylation status in dependence periodontal disease (controls: 100%, periodontitis patients: 100% methylation, ns). In gingival tissue a distinct decrease in methylation was obviously in CP-patients compared to AP-patients (56.9% vs. 65%, p=0.085). Conclusion: For the first time a change of epigenetic pattern in TNFa-gene was assessed comparing inflamed gingival tissue and venous blood. However, because of the small cohorts the results obtained could only be regarded as preliminary and should be verified in larger cohorts. Schlagwörter: epigenetics, periodontitis, TNFa

Skeletal changes accompanying aging or chronic inflammatory disorders, such as rheumatoid arthritis, osteoporosis, peri-implantitis and periodontitis, are associated with both increased risk of fractures and systemic bone loss. These changes occur through inflammatory cytokine-mediated stimulation of osteoclast resorption and inhibition of osteoblast function. Tumor necrosis factor-alpha (TNF-alpha), a pro-inflammatory cytokine with a profound role in many skeletal diseases, has been described as a mediator of bone loss in osteolysis and other inflammatory bone diseases. In addition to its known bone resorptive action, TNF-alpha reduces bone formation by inhibiting osteoblast differentiation (1). Recently, it was shown that N-methyl pyrrolidone (NMP) enhance bone formation and inhibit osteoclast differentiation and function (2, 3). Here, we investigated the effects of NMP on osteoblast differentiation using mouse C2C12 cells, a widely used model to examine the early stages of osteoblast differentiation, in the presence of TNF-alpha. The addition of TNF-alpha to C2C12 cells suppressed the Bone Morphogenetic Protein (BMP)-2-induced expression of key osteoblastic markers including Runx2 and alkaline phosphatase activity (ALP). NMP had no independent effects on Runx2 and alkaline phosphatase activity; however, it repressed the suppressive effects of TNF-alpha. Further results suggest that TNF-alpha inhibits BMP-2-induced osteoblast differentiation probably by modulating p38 phosphorylation. NMP reversed this effect by a mechanism involving p38 and ERK pathways. Moreover, NMP inhibited TNF-alpha stimulated TNF-alpha receptor 1 and 2 (TNFR1 and TNFR2) expression. All together, these results demonstrated that NMP promotes BMP -2-induced osteoblastic differentiation impaired by TNF-alpha, suggesting a possible role of NMP as a potent drug for bone regeneration or for the treatment of bone diseases associated with excessive bone resorption. Schlagwörter: bone morphogenetic protein, N-methyl pyrrolidone, osteoinduction, tumor necrosis factor

Management of the ranula is controversial. There are several different options, each with advantages and disadvantages. A retrospective patient file analysis of 35 cases treated in our hospital showed that excision of the ipsilateral sublingual gland with ranula excission (true cyst) or with evacuation of the ranula (pseudocyst) is first choice treatment for oral and plunging ranula. Schlagwörter: ranula, treatment, recurrence

Aim: Ozone has been used for biofilm management of carious lesions for a long time. While adjunctive antibacterial strategies are part of periodontal therapy to eliminate or reduce the number of periodontopathogenes, their main focus so far is the application of antiseptic mouthrinses or antibiotics. However, administration of ozone could be beneficial and represent another therapeutic approach. It was the aim of this study to develop an experimental design to test the reduction of Aggregatibacter actinomycetemcomitans (A. a.) und Porphyromonas gingivalis (P. g.) after application of gaseous ozone in vitro. Method: Two strains of A. a. (A. a. 3-2-2 and 10-1-3) and P. g. (P. g. 1711 and P. g. USA) were cultivated under microaerophilic and anaerobic conditions. Strains were diluted to an initial count of 1E+08 bacteria per ml. In group 1, an aliquot of 10 µl bacterial suspension was covered with 50 µl agarose to simulate the existence of saliva in the clinical situation. In groups 2 and 3, an aliquot of 10 µl without agarose was suspended. Gaseous ozone was applied in groups 1 and 2 for 20, 30, 40, 50, 60 und 80 s. Group 3 was the control group that remained untreated. After the treatment, the samples were cultivated again for 7 days, then colony forming units (cfu) were counted. Experiments were repeated 10 times at all time intervals and in each group. Statistics: The significance level was set at 5 %. Data were analysed by one-way ANOVA. Post-hoc the Student-Newman-Keuls-Procedure was used to analyse differences between the three groups. The t-test was applied to find differences between obligate and facultative anaerobes and the two strains of A. a. and P. g. Results: In both test groups, the number of bacteria was reduced significantly by ozone application in comparison to the untreated control group. In group 1, the number of viable bacteria decreased by two log units after an application time of 80 s while this reduction was reached in group 2 already after 60 s. No changes happened in the control group. Clinically meaningful and statistically significant reductions between A. a. und P. g. occurred in group 2 after 80 s only. Differences in between the species were detected. Conclusions: Ozone exhibits an antibacterial effect on A. a. and P. g. in vitro. Covering of bacteria with agarose inhibits this effect.

Objective: The aim of the present study was to evaluate the inflence of different concentrations of chlorhexidindigluconate (CHX) on microtensile bond strength (mTBS) of two self-etching dentin adhesives (Futurabond NR, Bond Force) in vitro. Methods: 150 extracted third molars were included in this study. All teeth were specially prepared allowing the simulation of dentin perfusion. The specimens were randomly assigned to one of the ten groups of fifteen samples each: group F-C: Futurabond NR, control group (no CHX-application); F-0.2: immersion for five minutes in 0.2% CHX prior to bonding with Futurabond, F-2: immersion for five minutes in 5% CHX prior to bonding, F-5: immersion for five minutes in 2% CHX prior to bonding, groups B-C, B-0.2, B-2 and B-5 followed the same procedure with Bond Force as adhesive. MTBS was measured 15 minutes after application of the composite (Tetric Ceram) using an universal testing machine. Results: Statistical analysis showed a significant influence of the used dentin adhesive and the pre-treatment with CHX in different concentrations (p 0.001, ANOVA). The application of 2% and 5% CHX before bonding procedure (F-2, F-5, B-2, B-5) resulted in a significant reduction of mTBS compared to the untreated control groups (F-C, B-C) (p 0.05, Tukey's test). Between the controls and the 0.2% CHX-groups, no significant differences could be detected (p 0.05, Tukey's test). Pairwise comparison between Futurabond and Bond Force showed no significant differences in all groups (p 0.05, Tukey's test). Conclusions: Within the limitations of an in vitro investigation it can be concluded that CHX in higher concentrations affected the mTBS of both tested self-etching adhesive systems. Schlagwörter: CHX, microtensile bond strength, self-etch adhesives

Background: Periodontitis is initiated by the subgingival occurrence of periodontopathogens. It is triggered by specific host dependent immune response which is influenced by the genetic predisposition. Polymorphisms in the interleukin 1 (IL-1) gene cluster have been suggested to influence the pathogenesis of periodontitis. Patients and methods: A total of 159 periodontitis patients (chronic: n=73, aggressive: n=86) and 89 periodontitisfree controls were included in the study. Polymorphisms IL-1a (rs1800587), IL-1b (rs16944, rs1143634), IL-1 receptor (rs2234650), and IL-1 receptor antagonist (rs315952) were determined by polymerase chain reaction with sequence-specific primers (PCR-SSP). Subgingival bacterial colonization was assessed using a polymerase chain reaction (PCR)/DNA probe test (micro-Ident®). Haplotype block structure was determined using Haploview 4.2. Statistical analyses were performed applying SPSS 17.0 considering dominant, recessive and codominant genetic models. Results: In this case-control-study no association between genomic variants of the IL-1 gene cluster and the incidence of severe periodontitis could be shown. Carriers of the rare genotypes of rs1800587 (pcorr.=0.009), rs1143634 (pcorr.=0.009) and composite genotype (rs1800587+rs1143634) (pcorr.=0.031) had a 2-fold higher risk for subgingival occurrence of A. actinomycetemcomitans. In forward stepwise binary logistic regression analyses considering age, gender, smoking, approximal plaque index as potential confounders these significant associations were proven. Conclusions: Despite the genetic background of IL-1 gene cluster could be shown to be associated with subgingival colonization of A. actinomycetemcomitans there is no evidence that it is an independent risk indicator for periodontitis. Schlagwörter: interleukin-1, genetic, A. actinomycetemcomitans

In recent decades, we have seen the development of numerous imaging modalities that have revolutionized dental and medical diagnosis. Optical Coherence Tomography (OCT) is one among them. OCT is mainly used in ophthalmology and it also represents a major advancement in imaging in dentistry, due to its ability to provide detailed characterization of dental microstructure, enabling the dentists to make earlier and more accurate chairside diagnosis of oral disease. OCT is a noninvasive diagnostic imaging modality which enables invivo cross- sectional, 3 dimensional, and tomographic visualization of the internal microstructure in biological systems. This poster is presented as review about the history, principle and its application in dentistry and especially in Oral Medicine for early screening for precancerous lesions and oral cancer. Schlagwörter: Optical Coherence Tomography (OCT), dental imaging, chair-side diagnosis, noninvasive diagnostic imaging

Objectives: The aim was to evaluate the effect of different concentrations of NaOCl on microtensile bond strength (mTBS) of a dual-curing total-etch adhesive (LuxaBond-Total Etch) in combination with a dual-curing composite (Luxacore Z-Dual) on pulpal dentin in vitro. Material and Methods: Seventy-two extracted third molars were included. Dentin specimens of the pulp chamber were obtained under standardized conditions. The specimens were randomly assigned to one of the six groups of twelve samples each: L-C: Luxabond/Luxacore (light-curing), control (no NaOCl-application); L-1: immersion in 1% NaOCl (24 hours) before bonding, L-5: immersion in 5% NaOCl (24 hours) before bonding; groups C-C, C-1, C-5 followed the same procedure using the self-curing mode. Results: After light-curing following mTBs could be observed (MPa): L-C: 30.9 (±3.7); L-1 26.6 (± 4.8); L-5: 19.8 (± 2.0). After using the self-curing mode mTBS was as followed: C-C:23.1 (± 4.4); C-1: 21.5 (4.6); C-5: 18.3 (2.1). Statistical analysis showed a significant influence of the used curing method and the different NaOCl concentrations (p0.001, ANOVA). The application of 1% and 5% NaOCl before bonding resulted in a reduction of mTBS. In the case of 5%, this difference was significant. Pairwise comparison between both curing groups showed no significant differences between L-C/C-C and L-1/C-1 (p 0.05, Tukey's test). Conclusions: It can be concluded that the curing method might have an influence on mTBS. The application of higher concentrations of NaOCl prior to bonding decreases mTBS. Clinical relevance: NaOCl is commonly used in endodontic treatment and might have an influence on mTBs. Schlagwörter: microtensile bond strength, NaOCl, dentin adhesive

The succesfull complete denture therapy could benefit, in case of xerostomic patient, from studies on wettability of denture base materials with natural or artificial saliva. The initial state of wettability for different denture base materialsrepresents a starting point for the evaluation of any type of surface treatment. Artificial saliva has better wettability with all tested resins. Artificial saliva and further surface treatment can improve quality of life for the xerostomic patient. Schlagwörter: wettability, denture base, natural saliva, artificial saliva

Over the past thirty years, clinicians have been restoring aesthetics and function in edentulous patients with implant-supported overdentures using different retention systems. The choice of prosthesis retention has significant economic implications but it is not well known if there are specific clinical implications, particularly with regard to treatment's success as well as patient satisfaction therefore is critically important to determine whether there are meaningful differences in outcomes, based on the type of retention used. The purpose of this study was to evaluate subjects\' satisfaction correlated with total costs during a four years randomized clinical trial of implant-retained mandibular complete dentures attached by Retentive Anchors (Balls - B), Magnets (M) or Locator System (L) to Straumann endosteal dental implants.The 69 patients enrolled in the study were followed every 6 month for 4 years and detailed records were kept of costs, extent of maintenance required after placement of the dentures, general satisfaction as well as comfort, stability, masticator efficiency, speech, aesthetic and cleaning ability. All three groups had less oral health related quality of life problems than before treatment. The Magnet group has the highest cost for the components but less maintenance requirements.The Ball and Locator groups scored higher rating on comfort, stability and ability to chew comparing to the Magnet group. Although the retention force of the Magnet attachment is smaller, patient satisfaction is high at all groups. Schlagwörter: mandible, implant, overdenture, locator, retentive anchor, magnet

Objectives: The aim of this study was to evaluate the effect of a recently introduced desensitizing paste based on Pro-Argin technology (elmex Sensitive Professional Desensitizing Paste, GABA, Germany) on microtensile bond strength of a total etch adhesive system (Syntac, Vivadent, Liechtenstein) after artificial aging using water storage and application of a provisional cement (Temp Bond, Kerr, Germany). Methods: 60 freshly extracted third molars were included. All teeth were specially prepared allowing the simulation of dentin perfusion and standardized conditions. The specimens were randomly assigned to four experimental groups of fifteen each: group 1: control without desensitizer; group 2: desensitizing paste application; group 3: desensitizing paste, water storage; group 4: desensitizing paste, application of Temp Bond, water storage. Group 3 and 4 were stored in water for one week. In group 3 Temp Bond was additionally applied after desensitizer application. Microtensile bond strength was measured using a Zwick testing machine. Results: For the test series following tensile bond strengths were evaluated (mean values and standard deviations in MPa): Group 1: 24.66 (±7.96), group 2: 15.54 (±2.99), group 3: 13.61 (± 2.25), group 4: 16.16 (± 1.55). Statistical analysis showed a significant influence of the different aging procedures on microtensile bond strength (p 0.001, ANOVA). After application of the desensitizing paste a significant reduction of bond strength could be observed compared with the untreated control (p 0.05, Tukey test). Pairwise comparison showed no further significant reduction of bond strength in specimen after water storage and application of the provisional cement (p> 0.05, Tukey test). Conclusions: Within the limitations of an in vitro investigation it can be concluded that application of the desensitizing paste based on Pro-Argin technology might affect microtensile bond strength of the used total etch adhesive system. Schlagwörter: dentin hypersensitivity, dentin, bond strength, desensitizer, aging

The advantages of keeping natural roots have been mentioned often in complete overdenture technologies. In this study we analyzed only removable partial dentures with extra-coronal ball attachments on the main abutments and magnets on the auxiliary ones. Patient's satisfaction concerning chewing ability, retention and stabilization of the denture was highly superior in presence of the molars with magnets under the free-end saddles then in their absence. The use of magnets presented various difficulties in different clinical situations. Teeth that suffer from moderate periodontal disease with concomitant bone loss can be used as abutments if the initial design of the denture is made in such manner that the loss of these auxiliary abutments does not imply the loss of the denture. Schlagwörter: removable partial overdenture, auxiliary abutment, magnet

Introduction: Quality endodontic surgical treatment is directly related to correct incision planning, flap design, root end resection and retro filling. Biodentine, a calicium silicate based cement, is biocompatible and bioactive with improved handling properties and is supposed to be a good retrofilling material and is comparative with other root endo restorarive material like MTA. It has better handling which is of importance during endodontic surgery. Objective: Comparative evaluation of the marginal adaptation of biodentine, mineral trioxide aggregate(MTA) and glass ionomer cement as root end filling materials. Materials and Methods: The study has been carried out on 45 extracted single rooted human teeth (15 for each group). Root canals were cleaned, shaped and obturated using gutta percha and apexit as root canal sealer. After 3mm of root resection, root end cavities of 3mm deep were prepared. 15 samples in each group were root-end filled with biodentine, pro-root MTA and glass ionomer cement and imaged using scanning electron microscope. Results: The SEM microphotographies show Biodentine and MTA both exhibited better marginal adaptation to dentin walls as compared to glass ionomer cement. Conclusion: Biodentine, a newly introduced material showed promising result under scanning electron microscope and is recommended to be tried in vivo. Schlagwörter: retro filling material, biodentine, marginal adaptation