International Poster Journal of Dentistry and Oral Medicine, 04/2011

Two experimental GIC-based root canal ‎sealers were prepared for the purpose of the ‎study with a main formula of boro-tri-fluoro-‎alumino-silicate (BTFAS) for the test-1 and ‎strontium fluoride SrF2 for test-2. Ninety ‎specimens of human sound teeth were embedded ‎into an acrylic mould. A conventional root canal ‎preparation without root canal filling was ‎performed. After sectioning the teeth ‎longitudinally, the internal side of the canal was ‎subjected to a demineralising solution to produce ‎a caries-like lesion. After the end of each ‎demineralizing period, the specimens were ‎examined under transversal micro-radiography ‎to have the (control radiographs). Then a film ‎layer of the experimental sealer test-1 was applied ‎to half of the specimens (n=45) and another film ‎of experimental sealer test-2 was applied to the ‎rest of the specimens (n=45). The test specimens ‎were divided into three time groups to be re-‎evaluated by transversal micro-radiography (test-‎radiographs) after 14 days, 28 days, and two ‎months. The specimens were further sectioned ‎and examined under SEM to support the ‎findings of transversal radio-micrograph. The ‎results illustrate a significant difference between ‎the two months test group and the control ‎radiographs but with no significant differences ‎among the other groups. It was obvious that the ‎secondary canals were ‎changed in texture which may be attributed to ‎precipitation of mineral ions by the glass Ionomer ‎sealer. The study needs further investigations to ‎prove the research hypothesis. ‎ Keywords: glass ionomer cement, remineralization, root canal sealer, secondary canals, demineralization

18 pairs of complete dentures were manufactured at Faculty of Dentistry Timisoara, from different heat-curing dental resisns: Superacryl, Triplex, Vertex. 6 pairs were tested directly on the mechanical testing machine LBG 100T, other 6 had as support the plaster model and other 6 were adapted on models with help of silicone (Lastic Xtra, Kettenbach, Germany). The dentures were tested at compression, until they broke, by applying forces on their occlusal surfaces. The results emphasized a rapid braking of the dentures that didn't have any support. The slowest fracture took place in case of the dentures adapted on model with help of silicone. The braking happened at 2,1 kN, The more intimate adaptation to prosthetic field the prostheses have, the more resistant they are. Denture's mechanical behavior is connected to resin's properties. Keywords: complete dentures, compression test, dental resins

The aim of the study was to evaluate the fracture behavior of Eclipse Resin System, used in complete dentures technology. 30 samples were evaluated with Zwick Roel device. All samples had defects: The analysis of fracture behavior was performed with an Olympus type SZX7 stereo-microscope. On transverse section, samples breaking had an initiation zone: 15% in center and 85% at the edge. The zone of final fracture was sharp, with granular aspect. The fractured samples showed brittle characteristics without massive elongation of plastic deformation before fracture. Defects from material\'s structure had a negative impact on mechanical resistance of prostheses. Keywords: fracture, dental resins

Aim: It was the purpose of the study to examine the effect of two desensitizers (Hyposen, lege artis Pharma GmbH, and the upon Pro-Argin ™ technology based Elmex® Sensitive Professional™ Desensitizing Paste, GABA) on the microtensile strength of an adhesive system (Bifix QM, Voco) after artificial aging by water storage and application of a temporary cement (Provicol QM, Voco). Material and method: The preparation of 105 dentin specimens permitted the simulation of the dentin perfusion and application of the materials under standardised conditions. The specimens were divided by chance into seven experimental groups of 15 each: 1: Control without desensitizers; 2: Hyposen; 3: Hyposen, water storage; 4: Hyposen, Provicol, water storage; 5: Paste application; 6: Paste application, water storage; 7: Paste application, Provicol, water storage. The groups 3, 4, 6 and 7 were stored one week in saline. In the groups 4 and 7 the temporary cement was applied additionally after the application of the desensitizers. The microtensile bond strength was determined using an universal test machine. Results: For the test rows the following values were determined (averages and standard deviation in MPa): 1: 14.04 (±2.64), 2: 13.16 (±2.12), 3: 13.68 (±2.77), 4: 12.27 (±2.42), 5: 12.20 (±1.94), 6: 12.68 (±1.72), 7: 10.61 (±1.85). The statistical analysis showed a significant influence of the used desensitizers and the aging procedures on microtensile bond strength (p 0.001, ANOVA). In comparison to the control group the application of both desensitizers and water storage led not to a significant reduction of the tensile bond strength. Compared to the control group additional application of the temporary cement reduced the tensile strength in the group 7 significantly (p 0.05, Tukey\'s test). Conclusion: Within the limitations of an in vitro investigation it cn be concluded, that the application of both Desensitizer does not influence the tensile bond strength of the used adhesive system. Indeed, the additional use of a temporary cement can influence tensile bond strength. Keywords: dentin bonding agents, dentin, bond strength, desensitizer, dentin hypersensitivity

Cutting of soft tissues is an important procedure in oral surgery. Besides of established instruments exist various dissection techniques of minimally invasive surgery, which are not evaluated for oral applications. The aim of this in vitro experimental study was to perform a histological evaluation of incision effects produced in oral mucosa with modern cutting instruments of dental and visceral surgery. Keywords: histological evaluation, oral mucosa, cutting instruments, in vitro study

The study used samples of material and an upper complete denture, made by Eclipse Resin System (DENTSPLY International Inc. - DeguDent GmbH, Hanau Germany). By 3D scanning (Roland 3D laser scanner, model LPX-1200) was obtained the geometric model of the complete denture. This was imported into o finite element software - ABAQUS/CAE V6.6 and was determined the state of stress and the stress intensity factors for three located defects. For Eclipse Base Plate there were obtained following mechanical properties: the tensile strength - σU=59.49 MPa, Young's modulus - E=2908.45 MPa and fracture toughness KC=24.93 MPa √mm. Defects located on palatal mid-line of upper complete denture, especially those at the junction between different support areas, generate tensile stress and deformation which can determine possible mid-line fractures Keywords: complete dentures, fracture mechanics

Objectives: Oral cancer is a considerable health problem with more than 10,000 new diagnosed cases each year in Germany. Comparably little is known about the knowledge of the public on oral cancer and its possible relationship to socioeconomic parameters. It was the aim of this project to investigate the knowledge about risk factors of oral cancer in the State of Schleswig-Holstein in Germany. Methods: A well-known German polling firm formulated a telephone-based survey based on a standardized questionnaire. This survey was validated by a pretest and a representative survey (n=1000) via computer-aided telephone interview (CATI) was carried out by the polling firm within the public of Schleswig-Holstein, Germany. Descriptive statistics of demographic variables of the sample and responses to the questionnaire were reported by means of counts and percentages. Knowledge of the risk factors was further classified according to different socioeconomic categories and their subgroups. All analyses were done with the SPSS for Windows 15.0 software. Results: More than 70% of the sample of the public knew use of tobacco and a prior oral cancer lesion as risk factors. Other risk factors, such as the consumption of alcohol and older age were only identified by around 50% of the sample. The detailed analysis revealed a relationship between a low level of knowledge and socioeconomic factors such as older age, low level of education, occupations such as e.g. blue collar worker and a low income. Conclusions: The survey illustrated that the public of Schleswig-Holstein is not well-informed about the risk factors of oral cancer. In addition, the low level of knowledge was associated with a low level of certain socioeconomic factors. Improved targeted health education and health promotion strategies for the public are recommended to improve early detection and ultimately the prognosis of oral cancer. Keywords: oral cancer, public, risk factors, knowledge, Germany

Aim: The aim of the study was to determine the influence of the sterilization on the fracture behaviour nickel- titanium endodontic instruments (Mtwo 25/ 06) in two different standardised artificial root canals. Material and method: The investigation was realised in 80 new nickel- titanium files of the size 25/06. In each case 20 files were submitted to a different number by disinfection- and sterilization cycles (0, 5, 10, 15 cycles). Afterwards the files were introduced with the help of a standardised experiment set-up in two differently very curved, artificial root canals up to a working length of 16 mm. All files were loaded with a steady speed (300 U/min) up to the break of the file. The time (seconds) up to the fracture was determined. The statistical evaluation of the results of eight test groups was carried out with ANOVA and Tukey's test (SPSS 17.0) Results: With the very curved root canal it has come after 107,7 (± 14,4) seconds to the fracture of the new files. After the sterilization the following values were determined: 5 cycles: 90,9 (± 9,4); 10 cycles: 76,6 (± 10,1); 15 cycles: 69,9 (± 5,1). The less curved root canal showed the following values: 0 cycles: 332,9 (±40,1); 5 cycles: 291,4 (± 29,2); 10 cycles: 289,6 (± 26,5); 15 cycles: 273,7(±38,7). The statistical evaluation showed a significant influence of the canal bend on the fracture behavior (p 0,001, ANOVA). The influence of the sterilization was significant with both canal forms in comparison to the unsterilised files. After the different number of sterilization cycles no significant difference of the fracture time could be observed with both canal forms. Conclusion: It can be found out that the fracture time is influenced, on the one hand, significantly by the canal bend and on the other hand decisively by the first sterilization cycles. Keywords: root canals, nickel-titanium instruments, sterilization

Objective: The precise transfer of the intraoral implant position to a master cast is a prerequisite for an accurate and passive fit of the prosthetic superstructure and for long-term success. Therefore, the aim of this in-vitro study was to investigate the influence of the implant system, impression material and technique on the transfer accuracy of implant impressions. Methods: An acrylic resin model of the maxilla with a steel base plate was used as a reference. Six implants of two different implant systems (three Xive and three Ankylos implants; Dentsply Friadent) were fixed in the reference model. The pick-up and the reposition impression techniques were used to make 10 impressions with the following materials: Impregum Penta (3M ESPE), Aquasil Monophase (Dentsply DeTrey), P2 Monophase and Flexitime Monophase (both Heraeus Kulzer). Master casts were fabricated with Fuji Rock (GC-Corporation, Tokio, Japan). Measuring abutments were fixed on the implant analogs and the 3D coordinates of each implant position was recorded with a 3D coordinate measuring machine (Rapid CNC, THOME, Germany). Subsequently mean deviation (inclination, overall 3D shift in XYZ direction) was calculated in relation to the reference model. Statistical analysis was performed using ANOVA (α=0.05). Results: The impression technique had a significant influence (p0.05) on the transfer accuracy. The pick-up technique had a significant positive effect on inclination (p0.01). The implants of the Ankylos system showed a higher accuracy with regard to inclination (0.09° ± 0.018°) compared to the Xive implants (-0.15 ± 0.018°). However, the 3D shift was significantly smaller (p0.001) with Xive implants (0.10mm ± 0.06mm) compared to Ankylos implants (0.14mm ± 0.04mm). The impression material had only a minor influence on the transfer accuracy. Conclusions: Under the limits of the study it can be concluded that the pick-up technique produces more accurate casts and should therefore be favoured for daily practice. Keywords: transfer accuracy, impression technique, implant system, impression material

Objectives:The aim of this study was to evaluate the effect of different irradiation doses on microtensile bond strength (mTBS) of four different dentin adhesives/compomer combinations1,2,3,4 on perfused primary dentin in vitro. Materials and methods: 144 freshly extracted primary molarswere included. All teethwere specially prepared allowing the simulation of dentin perfusion and standardized conditions. According to four different dentin adhesives and three irradiation doses (0 Gy, 6 Gy and 60 Gy), the specimens were randomly assigned to 12 experimental groups of 12 each: Syntac (S0, S6, S60), Prime&Bond (P0, P6, P60), Futurabond (F0, F6, F60), Optibond (O0, O6, O60). Each specimen was irradiated fractionally with 2 Gy/day (6mV, X-Ray) using a linear accelerator, respectively, depending on the experimental irradiation dose group. All materials were applied as recommended by the manufacturer. Microtensile bond strength was measured 15 min after application of the fissure sealant using a universal testing machine. Statistical analysis was performed using SPSS 15.0. Results: Statistical analysis showed a significant influence of irradiation on microtensile bond strength (p 0.001, ANOVA). The highest mTBS were found in the non-irradiated groups (S0, P0, F0, O0), the lowest mTBS were observed in specimens irradiated with 60 Gy (S60, P60, F60, O60). Comparison of the dentin adhesives in non-irradiated groups showed significant higher values in specimens treated with Optibond compared to group S0 (p 0.05, Tukey's test). Between groups S0, P0 and F0 no significant difference could be detected (p > 0.05, Tukey's test). The influence of irradiation was significant in the 60 Gy groups except for Syntac (Tukey's test, p 0.05). Irradiation doses of 6 Gy did not show any significant influence compared to non-irradiated groups (0 Gy). Conclusions: Within the limitations of this in vitro investigation it can be concluded that irradiation of primary teeth in doses of 60 Gy might affect microtensile bond strength of dentin adhesive/compomer combinations.

Objective: The aim of this prospective long-term study was to evaluate the clinical performance of the selfetch adhesive AdheSE One (Ivoclar Vivadent) in combination with the composite Tetric Evo Ceram (Ivoclar Vivadent) for class I and II restorations. The improvement of the marginal adaptation with the additional use of a flowable resin composite (Tetric Flow, Ivoclar Vivadent) for cavity lining was tested. Methods: In accordance with a split mouth design, 50 patients received 100 restorations in premolars and molars. A total of 32 class I and 68 class II cavities were restored. After using the adhesive system AdheSE One, in group T the restorations were placed with Tetric Evo Ceram and in group TF there was applied an additional layer of the flowable composite before placing the restoration also with Tetric Evo Ceram. Each restoration was scored according to the modified Ryge criteria at baseline, after 6, 12, 24 and 36 months. Results: After 36 months (recall rate 80%) the results of the Ryge evaluation for both groups without/ and with application of Tetric Flow were: marginal adaption: Alpha: 34/35, Bravo: 2/5, Charlie: 1/0, Delta: 1/0; marginal discoloration: Alfa: 30/36, Bravo: 8/4; filling integrity: Alfa: 37/39, Bravo: 1/1. All restored teeth remained vital, the parameter hypersensitivity, recurrent caries, surface, colour match and proximal contact were scored Alfa for all teeth. Between both groups no statistical significant differences could be detected (Mann- Whitney- U- Test, p0,05). The cumulative failure rate was 7,7% for group T and 0% for group TF. Conclusion: After 36 months clinical use of AdheSE One in stress-bearing posterior cavities reached acceptable clinical results in both groups. Keywords: clinical study, selfetch adhesive, flowable composite, ryge criteria, composite resin

Objectives: The aim of this study was to investigate the efficacy of a novel desensitizing paste based on Pro-Argin™ technology (GABA GmbH) on hypersensitive teeth before and after professional tooth cleaning. Materials and Methods: A total of 26 male and female patients (aged between 23 and 67 years, middle 45 years) with established dentin hypersensitivity (as least one hypersensitive tooth with a tactile sensitivity score) were randomly assigned in two groups. Group 1: before PTC the paste was applied; group 2: after PTC the paste was applied as final polishing step. Before starting the procedure, the tooth was stimulated 1 sec. with air blast and then the patient was asked to report the sensitivity (rating scale: slight, partial, moderate, severe). The desensitizing paste was applied to the gingivo-facial third of the selected tooth (or teeth) using a rotating prophy cup. The tested tooth (teeth) was (were) re-stimulated as prior to treatment and the patient was asked to describe any change in sensitivity (rating scale: total, improved, none). Results: After treatment with the desensitizing paste 42 of 50 teeth yielded reduction in dentin hypersensitivity. Group 1 showed an improvement in 20 of 28 teeth (71, 5%). Thereof 11 teeth were completely improved and 9 teeth conceived advancement. 8 teeth (28,5 %) showed no improvement of dentin hypersensitivity. Group 2 showed 16 completely and 6 partially improved teeth. Conclusions: Within the limitation of this first clinical survey and in consideration of the individual sensation of pain, it can be concluded that this desensitizing paste achieved good successes on hypersensitivity cervical areas when applied before and after PTC. However the effectiveness could be influenced through mechanical manipulation. Keywords: dentin hypersensitivity, dentin, pain, desensitizing paste, clinical survey

The normal internal temperature in resting man is maintained within very narrow limits, inspite of wide variations in the environmental temperature. Under steady state condition heat flows from production site in the body to cooler tissues and blood distributes this heat to the body surface from where it is dissipated to the external environment by radiation, convection and evaporation. The importance of deep body temperature as an indicator of disease has been known for centuries; but in recent years attention has been paid to the significance of skin temperature. So thermography was developed, which is a measuring technique that portray surface temperature distributions pictorially, painlessly and is free of radiation. This is accomplished either with liquid crystals or infrared scanning equipment. This technology lost favour some 20 years ago, but with new ultra sensitive high resolution digital infrared devices, efficacy is much improved. This poster presentation is an attempt to show that modern thermography can also be used as an adjunctive diagnostic and preventive medicine tool. Keywords: thermogram, infra-red radiation, heat, imaging, temperature, medical thermograpy, oral and maxillo-facial thermography

One of the major diseases affecting mankind is caries and pulpal diseases. Dental caries is one which remains a puzzle for the present generation. Dental caries prevention and eradication remains an enigma to researchers and dentists. The combination of genetics, engineering and biotechnology combined with dentistry resulted in a new era of modern dentistry with answers to these mysterious questions. Few researches in their early stages have proven that many latest methods with superior technologies are more effective in prevention, reversal, eradication with minimal intervention in treatment of caries. This poster highlights many future technologies like the Bluetooth device for pH detection and ozone therapy for caries reversal etc.that are under research, which can provide a glistening future to dentistry. The promising answer is that if dental practitioners adapt themselves to the future techniques, "DENTAL CARIES", the hidden enemy can be shrunken in its bud stage. Keywords: dental caries, caries diagnosis, caries reversal

Cyberknife is a high precision, painless, non-invasive robot guided frameless steriotactic radiosurgery system. It is the first and only radiosurgery system designed for treatment anywhere in the body. Cyberknife uses continual X-ray image guidance technology and computer-controlled robotic mobility to automatically track, detect, and correct for patient movements and target without interrupting the treatment. Cyberknife has proven to be effective alternative to surgery or conventional radiation for treating many conditions like vascular abnormalities-AVM, head and neck tumors, nasal and orbital tumors, cervical tumors, trigeminal neuralgia, pituitary adenomas in sub-millimeter accuracy and provides enhanced ability to avoid critical structures. Cyberknife gives a renewed ray of hope for a better quality of life especially for patients with previously diagnosed inoperable or inaccessible tumors and for those who have already received the maximum amount of radiation through other treatment methods and offers quick recovery and return to normal life. Keywords: Cyberknife, stereotactic, robotic mobility, sub-millimeter accuracy