International Poster Journal of Dentistry and Oral Medicine, 04/2006

This case report describes the incidental finding of the Chievitz organ in an unusually located cyst, which was detected during a distal wedge procedure while raising a mandibular flap on a 42 yo male patient with chronic periodontitis. The lesion occurred in the anterior aspect of the vertical ramus of the mandible, distally to a third molar 38 that was found with moderate mobility and lacking its antagonist. The tooth was left in place and the cyst was enucleated, based on evidence of radiographic radiotransparency, on clinical findings and on the decision to maintain the masticatory unit 27-37-38. The histopathological examination of the lesion was performed and the Chievitz organ was incidentally found. The treatment for the lesion is reported and the presence and significance of the Chievitz organ within the oral area is reviewed. Keywords: chievitz organ, atypical cyst

Introduction: An important criterion for the success of a crown is marginal fit. However, in the patient's mouth, fit can only be evaluated by subjective methods. This study describes the correlation between objective marginal fit and its subjective evaluation by dentists and dental technicians. Materials and methods: 30 human premolars and molars were randomly divided into 6 groups and prepared with a shoulder. For each of the 6 groups complete crowns were made of different alloys and technologies (casting: AuAgCu, AuPdPt, PdAgAu, CoCrMo, Ti and milling: Ti). The crowns were cemented with provisional cement. 10 dentists and 10 technicians were asked to evaluate the fit of the crowns with a new dental explorer. The crowns were then cleaned and cemented with a zincoxide phosphate cement. The marginal gaps of the crowns were examined under a computerized light microscope (x560). The means of the gaps were calculated for each group. Means of the gaps were calculated for each alloy and statistically compared using H-Test and U-Tests (pResults: Crowns made from different alloys and technologies showed partly significantly (pConclusion: Crowns from different alloys and technologies showed differences in marginal fit. The number of crowns with a satisfactory estimated marginal gap was decreasing with an increasing width of the marginal gap. It is suggested that within crowns with a small ( 90 µm) clinicians may use other criteria rather than marginal gaps to evaluate the fit of crowns. In this case over- or under contouring of crowns has possibly more importance in the clinical decision. Keywords: cast crowns, marginal gap, cement width, marginal fit

Being part of a detailed research project concerning the structural behaviour of a human mandible this paper concerns the influence of the periodontal ligament (PDL) on the structural behaviour of the entire mandible. In the field of implant dentistry, the simulation results provide a comparison of the physiological situation (natural teeth) and the changes due to dental implants. Keywords: human mandible, biomechanics, finite element simulation, periodontal ligament, adaptation of bone

Aims: The purpose of this study was to determine the differences in oral self-care levels between one hundred Romanian first year dental and general medical students. Materials and Methods: The examination was mainly based upon responses to a questionnaire titled 'Hiroshima University - Dental Behavioural Inventory (HU-DBI)'. Higher scores of the HU-DBI indicate better oral health attitudes/behaviour. Group comparisons were made using two-tailed Student's tests for interval level data, Mann-Whitney U-tests for ordinal level data and X2 test for categorical data. Statistical significance was based on probability values of less than 0.05. Results: The mean HU-DBI score of first year dental students was not significantly greater than that of the first year medical students (5.81 and 5.84, respectively; P>0.05). Of great significance were findings that while only 22 proportion of the medical students reported gum bleeding when they brush their teeth, 45% of the dental students did so (PConclusions: Although the difference in the HU-DBI score between the freshman dental and medical students was not statistically significant, there were considerable differences in dental health attitudes/behaviour among the two groups. Keywords: oral health behavior, dental students, medical students, dental education, gender, Romania

The objective of this study was to evaluate the influence of four desensitizers (Seal&Protect, Admira Protect, VivaSens, Hyposen) in situ.The root surfaces of freshly extracted human molars were thoroughly cleaned, thereby removing the cementum. From each tooth root dentin specimens were prepared. Ninety specimens were distributed among the following experimental groups: A: Seal&Protect, B: Admira Protect, C: VivaSens, D: Hyposen, E: control group, untreated. Two dentin specimens of each group were inserted into two buccal aspects of nine intraoral mandibular appliances. The appliances were worn for five weeks day and night. One side was brushed daily with a fluoride-containing toothpaste (Aronal). On the other side, plaque was allowed to grow. Individual oral hygiene techniques were performed without any fluorides. After the in situ period, two slabs (150 microns) were ground. The depth of the demineralized areas was determined using a polarized light microscope. For each group mean value and standard deviation were calculated. Statistical analysis was performed using SPSS 11.0. Concerning lesion depth, ANOVA revealed significant differences between brushed (b) and non-brushed (nb) specimens. Compared to the untreated control, lesion depths in groups A-D were significantly decreased in the brushed and also in the non-brushed subgroups (p Keywords: root dentin, demineralization, in situ, dentin adhesive, desensitizer

The aim of the present in vitro study was to compare the apical sealing ability of a warm vertical condensation system (EndoTwinn) with lateral condensation and Thermafil using two resin-based sealers (AH Plus, EndoRez). Sixty extracted single rooted incisors stored in saline were used. Each tooth was endodontically prepared using the Hero 642 system to a maximum size of 40. Working length was recorded 1 mm shorter than the anatomical apex. All teeth were randomly assigned to six experimental groups of nine each. Root canal fillings were performed using either warm vertical condensation (V), Thermafil obturators (T) or cold lateral condensation (L) with EndoRez (E) or AH Plus (A) as sealer. After root canal filling, the teeth were coated with nail varnish, leaving the apical foramen exposed and stored in 5% methylene blue solution for seven days. The apical 1 mm of each tooth was removed to reveal the apical limit of preparation. Four transverse sections of the teeth were taken at each millimetre from this point. The distribution of filling material in each canal was assessed by stereomicroscopic examination and areas of sealer (S), gutta-percha (G) and voids (V) were measured on the digital images. Statistical analysis was performed using ANOVA and Tukey's test. The total area of gutta-percha was not statistically different among the different obturation techniques (p Keywords: endodontics, root canal obturation, resin-based sealers

Aim: to evaluate ex-vivo the sealing ability of Thermafill system plus conventional sealer. Methodology: Thirty-two root-canals of single- and multi-rooted teeth with indication of extraction or amputation, were instrumented in vivo using the ProTaper (Dentsply-Maillefer, Ballaigues, Switzerland) instruments, NaOCl 1% and EDTA 17%. Working-length was set using Morita TrZX(Morita Mfg.Corp.-Japan) 0,5 mm short to apex. Root canals were obturated using the Thermafill system(Dentsply-Maillefer, Ballaigues-Switzerland) with sealer AHPlus(Dentsply-DeTrey GmbH, Konstanz-Germany). The obturated single-rooted-teeth were extracted, multi-rooted-teeth underwent amputation for periodontal reasons. Separated roots were embedded in acrylate. Transversal sections were performed at every 0.5mm up to 2.5mm. Sections were examined under direct, polarized light microscope and stereomicroscope(100X, 500X magnification). Images were captured using digital camera, photos elaborated with Camedia-Olympus-dpsoft-3.1, analyzed using AUTOCAD2002. Data were registered for each section: total perimeter of the canal, instrumented perimeter, perimeter in contact with obturation, total area of the canal, obturated area. Percentage of instrumented perimeter, of obturated perimeter and of obturated areas of the canals were calculated. Spectacular details-anatomical recesses, visible lateral canals, fractures, artifacts, foreign bodies, separated instruments were registrated. Results show increase in mean percentage of instrumented perimeter from 21%(phase 0=apex) to 66%(phase 6=2.5mm), increase in mean percentage of obturated area from 45%(phase 0) to 92%(phase 6) and a surprising slight, continuous decrease of mean percentage of obturated perimeter from 97%(phase 0) to 86%(phase 6). 40.6% of the samples displayed instrumentation, 46.9% displayed obturation on final 0.5mm, separated instruments and foreign bodies were found in 6.25%, 25% of sections displayed anatomical recesses, starting predominantly at 1.5 mm from the apex. Conclusions: Results show satisfactory, yet surprising picture of the outcome of treatment. Data must be refined by diversifying the groups according to tooth type, root shape, curvature, further compared with similar data from in-vitro studies, evaluation should be extended to various root-canal filling-systems. Keywords: root canal obturation, sealing ability, digital analysis

Periodontitis is a chronic inflammatory disorder of the periodontal supporting tissue of teeth. That's why several factors of the immune response and their genetic background have been proposed as potential markers for the development of this disease. However, existing data are very inconsistent. Therefore, the aim of the present study was to evaluate the importance of genomic variants of the potent proinflammatory cytokine TNF-a for the incidence of chronic and aggressive periodontitis. Methods: In the present study 66 periodontitis patients (chronic: n=34, mean age: 47+10.1y, 38.2% males; aggressive: n=32, mean age: 36.6+7.3y, 40.6% males) and 32 control probands without periodontitis (mean age: 41.6+10.3y, 40.6% males) were included. We investigated genotype, allele and haplotype frequencies of the TNFα-SNP -308G>A and -238G>A by use of PCR-SSP (CTS). Results: Hardy-Weinberg criteria were fulfilled for both SNPs in the patient groups. Investigating genotype and allele frequencies of both SNPs no significant disease specific differences could be detected in comparison with healthy controls. However, in the control group a distinct increase in the prevalence of the mutant genotypes (-308G>A: AG+AA; -238G>A: AG) and alleles (-308G>A: A, -238G>A: A), respectively could be described comparing with patients with chronic (-308G>A: 84.8%, -238G>A: 24.4%) and aggressive periodontitis (-308G>A: 39%, -238G>A: 133%). Compared with chronic (p=0.047), aggressive (p=0.024) and total patient group (p=0.015) in the control group a significant increase in carriers of the mutant haplotypes (haplotypes containing mutant A-allele vs. wildtype GG-GG) could be observed. Conclusions: The significant higher prevalence of carriers of the mutant haplotypes in the control group could be an indication for an altered, possibly more effective immune response to periodontal pathogens since these SNPs were considered to trigger the TNF-a production. Keywords: TNF-alpha, haplotype, aggressive periodontitis, chronic periodontitis

Introduction: Fit and surface quality of provisional crowns affect plaque adhesion and may cause gingival inflammation. Polishing temporary restorations in the dental lab gives excellent surface quality but is time consuming and has the risk of cross contamination due to contaminated pumice. Aim of this study was to describe the surface qualities of four different resin materials for fabrication of fixed provisional restorations after chairside polish with four recently developed polishing devices and to compare the results with the surface qualities which can be achieved by polishing in the dental lab. Material and Methods: The specimens of autopolymerizing and bis- acryl- composite materials were made according to the manufacturer's instructions. All were ground to produce a uniform and standard surface quality. Afterwards specimens of each material were polished chairside (testgroup) and in the dental lab in a standardized procedure (controlgroup). The surfaces before and after treatment were investigated by means of SEM and surface roughness measurements (Rz and Ra). Differences were statistically tested for significance by Kruskal-Wallace-Test and Man-Whitney-Test (Bonferroni, pResults: There were important differences between the surface qualities of dental lab polish and chairside devices in all acrylic materials. Dental lab polish provided the best results. The differences within the three rubber devices were not significant. The tested diamond finishing instruments produced inferior surface qualities in acrylic materials. Conclusion: Dental lab polish produced the best surface qualities in all materials. There were differences between several chairside polishing devices. However, all tested rubber polishing devices produced acceptable surface qualities for a short term application of provisional restorations. Keywords: provisional restorations, chairside polishing, surface roughness, resin