Poster 70, Sprache: Deutsch
Temporomandibular disorders (TMD) are supposed to be also possible risk factors or co- factors for general medical diseases. Correlation to specific headache symptoms, tinnitus and spinal pain disorders are established. The aim of the present investigation was to evaluate several signs and symptoms of TMD as a co- factor for frequent headache using a population based sample of the ongoing cross-sectional epidemiological study 'Study of Health in Pomerania' (Ship).
Medical, dental and sociodemographic parameters of 3146 representatively and according to age distribution selected subjects (age distribution 20-80 years) were checked for correlations with frequent headache symptoms using a multivariate logistic regression model. Frequent headache was defined asking the question: Do you suffer from following diseases: - headache, if yeas 1.
sometimes 2. often.3. always. Only the appearance of sometimes or often headache were used defining the variable. The model was adjusted for age, sex, level of education, income, TMD- symptoms and 32 chronic diseases. Significant values for the calculated odds ratios (OR) for the whole sample were found for pain on palpation of the masticatory muscles: 1-3 muscles painful: OR= 2.6, = muscles painful: OR= 4, tinnitus: OR = 2.8, sleeping disorders: OR= 1.9 and education level: OR= 2.0. The palpation pain of the muscles showed a dose dependence. As not significant turned out, to be smoking, alcohol abuse, and income, questions for pain in the TMJ- area, TMJ clicking, positive questions for several chronic diseases and education level. Gender separated regression models confirmed in general the results.
In this study we found, using an adjusted multivariate logistic regression model a significant and dose depended association between frequent headache and masticatory muscle pain.
Schlagwörter: Kopfschmerzen, Funktionsstörungen, orofaziales System
Poster 71, Sprache: Deutsch
The aim of this study was to assess the caries risk in 450 8-year-old Westphalian children by the clinical methods of the 'DAJ-criteria', the 'Schieber zur Kariesrisiko-Bestimmung' and the 'Dentoprog-method'. Caries was recorded using WHO diagnosing criteria. The caries risk was assessed for each child with all methods.
79.1% of the children had caries free permanent teeth. The mean caries experience was 7.6 dfs and 0.7 DMFS. Using the 'DAJ-criteria' (dft/DMFT > 5/7 or DT > 0/2) 19.8% of the 8-year-olds were identified at risk. By the 'Schieber zur Kariesrisiko-Bestimmung' a high caries risk was predicted for 47.8% of the children. Both methods agreed in 71% of low and high caries risk assessment. Comparing the agreement of the 'Schieber zur Kariesrisiko-Bestimmung' and the "Dentoprog-method" in caries risk assessment the same categorization was found for 94% of the children. The positive correlations (Spearman) of the risk predictors used by the 'Schieber zur Kariesrisiko-Bestimmung' and the "Dentoprog-method" compared to the caries prevalence as well as to the low number of caries free mixed dentitions (32%) indicated a correctly classified caries risk group with the 'Schieber zur Kariesrisiko-Bestimmung'.
This study suggests that the 'Schieber zur Kariesrisiko-Bestimmung' should be recommended as preventive orientated method for identification of caries risk patients in the annual dental examination by the dentists of the public health care system.
Schlagwörter: Kariesprävalenz, Kariesrisiko-Einschätzung, DAJ-Kriterien, Dentoprog-Methode, Schieber zur Kariesrisiko-Bestimmung
Poster 72, Sprache: Englisch
Different populations with adult periodontitis have been investigated for IL-1 genotypes. The aim of the present study was to investigate this genetic association in 2 forms of periodontitis: early onset- (EOP, n = 12) and adult periodontitis (AP, n=18). EOP patients were selected according to clinical parameters and radiographs (age
Schlagwörter: periodontitis, periodontal diagnosis, genetic polymorphisms, 1L-10 polymorphism, polymerase chain reaction
Poster 73, Sprache: Englisch
A key feature of the gingival epithelium is the protection of the periodontal tissue from microbial challenge. Especially in the gingival sulcus area, subgingival extension of a biofilm and the subsequent alterations of the epithelial layer may lead to periodontal destruction and loss of teeth. One of the characteristics of a functional epithelium is the developement of transepithelial electrical resistance (TER), a measurable indicator of epithelial integrity. In order to study the barrier function of epithelium we established an in vitro cell culture system. We used primary gingival keratinocytes and, as a positive control the MDCK I cell line, which is known to form very high TER values. Both cell types were seeded on collagen-coated cell culture inserts, grown to a confluent layer and the development of TER was detected with a volt-ohmmeter. With this system we are able to show an increase of TER which persists for 4-5 days. In order to enhance the TER values and subsequently the barrier function of the model system we used all-trans retinoic acid (RA) which is a potent regulator of epithelial differentiation. The daily application of RA led to an oscillation of the epithelial integrity resulting in an oscillation of the TER values whereas a one fold application of RA resulted in a delayed establishment of TER and the barrier function. Our results indicate that through topical application of RA one of the fundamental properties of the barrier function is profoundly influenced.
Schlagwörter: human oral keratinocytes, epithelial barrier, in vitro model
Poster 74, Sprache: Englisch
Endosseous implants are being placed with increasing frequency in the craniofacial region. The frontiers for craniofacial endosseous implants are expanded more and more. The present study describes a new application of craniofacial implants as anchoring elements for wigs.
In two patients (one male, 17 years; one female, 29 years) a split skin graft was used for closing a soft tissue defect in the occipital, parietal, temporal and frontal region (defect size between 10 and 33 cm respectively between 10 and 14 cm). The defect was caused by trauma or pilous naevus excision. A functionally and cosmetically sufficient provision of this hairless region by a conventional wig was not possible. Therefore six titanium implants (length 3 or 4 mm, width 3,75 mm) were placed in each patient. The fixtures were inserted into the cranium under general anaesthesia. Primary implant stability was reached in each implant. Six months after fixture installation abutment connection was performed in general respectively local anaesthesia. After a healing period about four weeks and after peri-implant soft tissue management titanium abutments were substituted by titanium magnetics. Subsequently a fixture retained wig was constructed. In a follow-up period between 3 and 15 months no fixtures have failed.
To date, the wigs are incoporated in both patients. The incorporated wigs have been shown to effectively retain a functionally and cosmetically successful craniofacial rehabilitation. Strategy, outcomes and complications of the treatment, especially regarding the peri-implant soft tissue, will be described and discussed.
Schlagwörter: craniofacial, endosseous implants, wigs
Poster 75, Sprache: Englisch
After resection of oropharyngeal tumors, 175 dental implants were placed in 18 irradiated (average = 44 Gy) and 22 non-irradiated patients between 1988 and 1997. Within a control period of 37 months on average, 15 implants failed. The reasons for implant failures were analysed. The analysis of implant failures revealed indicative parameters.
Primary failure of 11 implants (interval between implant placement and abutment placement) was recognized in four irradiated and two non-irradiated oral cancer patients. These fixtures showed no osseointegration during the healing period due to a mandibular fracture, overloading or unknown etiology. After prosthodontic rehabilitation four implants in two irradiated and two non-irradiated oral cancer patients were removed (secondary failure). These secondary losses occurred at an average of 39 months after second stage surgery and were caused by biomechanical overloading or peri-implant infection.
No osteoradionecrosis development due to implant failure was observed in irradiated patients. In all cases, peri-implant pocket depth, implant stability and peri-implant bone resorption increased before definitive secondary implant failure. Therefore, these findings seem to be useful as indicative parameters in the prediction of implant failure.
Schlagwörter: endosseous implants, oral cancer patients, irradiation, implant failure
Poster 76, Sprache: Englisch
Historically, a strict surgical implant protocol required a stress free healing period of 3 months for the mandible and 6 months for the maxilla between placement and functional loading of endosseous implants. An initial 2-week period without any removable prosthesis was recommended in edentulous patients. This inconvenient prospect of a long treatment period may preclude some patients from seeking implant treatment. However, such recommendations are a result of evaluating randomly chosen healing times during the initial phase of implant development. The level of predictability and high success of implant therapy in recent years have provided cause to reevaluate both the surgical and prosthetic protocol. In 1979 P.D. Ledermann described a technique of loading 4 rigidly bar-splinted implants in the edentulous mandible. The poster will revisit the approach of immediately loaded cylinder implants by a u-shaped bar in the edentulous mandible. Four grit-blasted and acid-etched screw implants (FRIALOC®, FRIADENT GmbH, Mannheim) are placed in the interforaminal area of the mental symphysis. Immediately after implant placement, an impression is made for the fabrication of a mesio-bar superstructure. The implants are loaded as early as one day after surgery with an implant-retained overdenture. It will be demonstrated that osseointegration can be achieved with a high level of predictability if the technique is properly applied. The approach of bar-prosthetic immediate loading will be presented and discussed on the basis of clinical and statistical data. The surgical and prosthetic management of mandibular implant-supported overdenture cases may be greatly simplified with the use of this technique in a selected group of patients. Dental rehabilitation time is shortened with relevant satisfaction for patients and improved function immediately after implant placement.
Schlagwörter: immediate loading, cross-arch stabilization, primary stability, transgingival implant
Poster 77, Sprache: Englisch
Objectives. Restorative dentistry searches for defect-orientated solutions for the esthetic reconstruction of missing teeth. In Zurich, a concept was developed for bonding composite fixed partial dentures (FPDs) to minimal invasive abutment preparations. In in-vitro tests and in a clinical study, conservative fiber-reinforced composite FPDs bonded to inlay abutments, were evaluated.
Material and Methods. In in-vitro tests, the marginal adaptation of 18 totally and selectively bonded three- and four-unit fiber-reinforced slot inlay FPDs (IFPDs) was evaluated using a computer controlled masticator. Before and after long-term thermo-mechanical loading, marginal adaptation was analyzed by scanning electron microscopy (SEM). In a clinical study, 60 defect-orientated fiber-reinforced composite IFPDs were inserted in 42 patients using a progressive protocol. The restorations were manufactured using the Targis&Vectris glass-fiber-reinforced composite system (Ivoclar, Schaan, Liechtenstein) and a simplified laboratory technique. The bonded IFPDs were observed over a period of two and a half years and were rated clinically by using the USPHS-criteria. Ten IFPDs were selected at random for SEM analysis.
Results. SEM analysis showed well above 90% of perfect margins and a negligible loss of marginal quality of selectively bonded abutment slot inlays after long-term thermo-mechanical loading. Clinically, patient's acceptance and satisfaction of the IFPDs was very high. Up to the present time, no changes in clinical quality have been detected during recall examinations using USPHS-criteria. SEM screening corroborated the clinical findings with an average of about 90% of perfect margins after one and two years.
Conclusion. Based on the results of the clinical study and the in-vitro results, bonded glass-fiber-reinforced composite IFPDs were considered clinically successful over the observation period.
Schlagwörter: Fiber-reinforced composite, inlay, fixed partial denture, clinical trial, marginal adaptation
Poster 78, Sprache: Deutsch
Objective: The aim of the present study was to compare the efficacy of guided tissue regeneration (GTR) using 2 different biodegradable barriers (polylactide acetyltributyl citrate; polydioxanon) in 3- and 2-wall infrabony defects. The polydioxanon barrier is an experimental membrane for GTR therapy that consists of a continuous occlusive barrier that has a layer of slings on the side that is meant to face the mucoperiosteal flap. Material and methods: 15 patients provided 15 pairs of similar contralateral periodontal defects: 12 predominantly 2-wall and 18 predominantly 3-wall infrabony defects. Each defect was randomly assigned to treatment with either polylactide acetyltributyl citrate (control [c]) or polydioxanon (test [t]) devices. At baseline, 6, 12, 18 and 24 months after surgery, clinical measurements (PlI, GI, PPD, PAL-V) were performed and standardized radiographs obtained (not at 18 months). Results: Both treatments revealed a significant GI reduction (p 0.05). A statistically significant gain of bone within the infrabony pockets was measured for both treatment options 24 months postsurgically [2.89±2.51 mm (t), 2.14±2.63 mm (c); p
Schlagwörter: biologisch abbaubare Barrieren, approximale infraalveoläre Defekte, röntgenologischer Knochengewinn
Poster 79, Sprache: Englisch
Traumatic injuries, cancer treatment and congenital disorders with abnormal bone shape or segmental bone loss requires replacement of missing bone. This may be accomplished by implantation of bone substitute material or by surgical transfer of natural tissue from an uninjured location elsewhere in the body. However, these procedures are limited due to different disadvantages. One strategy to overcome these problems is to develop living substitutes based on tissue engineering. As first step we have investigated the possibility to establish osteoblast cultures from facial bone.
After 14 days of culture the first cells grew out of the bone explants, after another 2-3 weeks the floor of the culture flask was covered by a subconfluent monolayer.
During subculturing procedures, the period to establish first and secondary passages was 14 days, further subculturing resulted in a further shortened culture period of only 5 to 7 days.
The morphometric assessment of the AP and Coll positive cells over the culture periods showed a maximal expression for both markers in the second passage. In the second passage in average 72 % of all cells stained for AP whereas 25 % resp. 42 % of all cells expressed AP in the first resp. in the third passage.
From cortico-cancellous bone chips of the maxilla cultures of human osteoblast like cells can be established. The amplification of these cells in subculture is easy to facilitate. A maximal expression of osteoblast differentiation markers like alkaline phosphatase and collagen I could be detected in the second and third passage. The demonstration of culturing sufficient differentiated osteoblast material originating from the human maxilla is a crucial step in respect to tissue engineering of bone which will find its application in cranio-maxillofacial surgery.
Schlagwörter: tissue engineering, bone, skull base
Poster 80, Sprache: Englisch
Introduction: Active cellular locomotion is a feature of diverse T cell types. Using a 3-D collagen matrix migration model in combination with computer-assisted cell tracking for reconstruction of migration paths and confocal microscopy, we investigated the locomotion behavior of CD8+ lymphocytes governing cell-dental material interactions due to the influence of different dental alloys. Material and methods: Locomotion of immunomagnetically isolated human CD8+ peripheral blood lymphocytes suspended in type I collagen gels was recorded using time-lapse videomicroscopy. Paths of randomly selected locomoting cells over a period of two hours were digitized, reconstructed and quantitatively analysed. A dental alloy free assay served as a control. We evaluated two different quantitative parameters: (1) the average percentage of CD8+ cells moving and (2) the velocity of the migrating CD8±cells due to the influence of serum-alloy-eluates. Results: We could show a reduction of average percentage of CD8+ cells migration in the presence of alloys (range from 13% up to 19,6%) in comparison to the average migration of 33% in the control. Concerning the velocity the same deminishing tendency could be seen (range from 3,8µm/min up to 2,4 µm/min for alloys, 6,3µm/min for controls). Discussion: We presume that the CD8+ cells are migrating in a 3-D collagen matrix migration model in a 'random-walk' fashion influenced by the components of serum-alloy-eluates. Recent studies (Entschladen et al. 1997) showed a spontaneous locomotion of CD8+ cells accompanied by enhanced tyrosine phosphorylation of the focal adhesion kinase (FAK). In contrast inhibition of protein tyrosine kinase (PTK) activity was overcome by subsequent activation of protein kinase C (PKC) using PMA. This PKC-driven locomotion is independent of tyrosine phosphorylation events indicating that the T lymphocyte locomotion is regulated by more than one signal transduction pathway. The analysis of these two 'driven-mechanisms' could be used as an indicator for biocompatibility of different dental materials. Supported by Heraeus-Kulzer
Schlagwörter: T-lymphocytes, Migration, dental alloy, Elution, Confocal Laser Scanning Microscopy (CLSM)