Poster 298, Language: EnglishDumitrescu, Alexandrina L./Donaldson, Lucy F.Aim of the study: to characterise a rat model of periodontitis for use in functional studies by analysis of alveolar bone loss in rats with experimentally-induced periodontitis.
Methods: Periodontal inflammation was induced by a single injection of 10 mg liposaccharide (LPS) (Salmonella typhimurium) in 1ml saline into rat mandibular gingiva at the buccomesial aspect of the second molar. Animals were killed after 7 days, mandibles dissected and sectioned for histological and immunocytochemical analysis.
Results: There was an 80% increase in the alveolar bone loss, measured as the distance between alveolar crest and the cemento-enamel junction, in LPS-injected animals compared to controls (468±230µm control, 830±270µm LPS, pConclusion: Intragingival injection of LPS in the rat provides an easily induced reproducible experimental model of periodontal inflammation that reiterates features of human disease.
Keywords: bone resorption, inflammation, lipopolysaccharide, osteoclast activation, periodontitis
Poster 299, Language: GermanZahn, Bernhard/Schacher, Beate/Oremek, Gerhard/Sauer-Eppel, Hildegund/Ratka-Krüger, PetraInflammation caused by periodontitis may have numerous systemic effects. One of the mediators influenced by periodontitis is C-reactive protein (CRP). Aim of this study was to determine if healthy subjects without peridontitis have a lower CRP-concentration compared to patients with chronic periodontitis. Further it should be evaluated if CRP-level decreases after a nonsurgical periodontal therapy. 21 systemically healthy patients with periodontitis (PERIO) and 11 persons without periodontitis as control group (C) were included. All persons had a clinical examination and provided blood to determine the CRP level. Following initial assessment, the periodontitis group received nonsurgical periodontal treatment. 6 weeks later, a second examination and CRP analysis was done. At baseline, subjects with periodontitis had a higher CRP level than the control group (PERIO: 0,36 ±0,3 mg/dl; C: 0,29 ±0,3 mg/dl). Treatment reduced probing depths and bleeding score significantly. After treatment, CRP-level decreased (0,27 ±0,3 mg/dl), but the differences found were not statistically significant. The results of this study point out that patients with chronic periodontitis may have higher CRP-level compared to healthy subjects and that a nonsurgical periodontal treatment can decrease CRP-concentration.
Keywords: C-reaktives Protein, chronische Parodontitis, Entzündung, nichtchirurgische Parodontitis-Therapie
Poster 300, Language: EnglishGernhardt, Christian Ralf/Fechner, Katrin/Schaller, Hans-GünterThe aim of the present investigation was to evaluate microtensile bond strength of four self-conditioning dentin adhesive systems (Xeno III, Clearfil SE Bond, Clearfil Protect Bond, Futurabond NR) in combination with a light-curing composite material (Clearfil AP-X) in vitro.
Methods: Sixty freshly extracted third molars were included. All teeth were specially prepared allowing the simulation of dentin perfusion. Dentin specimens with a total thickness of 1.5 mm were obtained under standardized conditions. The specimens were randomly assigned to four experimental groups: group A: Xeno III; group B; Clearfil SE Bond; group C: Clearfil Protect Bond; group D: Futurabond NR. All materials were applied on a surface area of 0.785mm² as recommended by the manufacturer. Microtensile bond strength (µ-TBS) of the above mentioned adhesive systems was measured 15 minutes after application and light curing of the composite material (colour A2) using an universal testing machine. Statistical analysis was performed using SPSS 10.0.
Results: For the four test series following microtensile bond strengths were evaluated (mean value and standard deviation in MPa): group A 27.29 (± 4.16), group B 32.23 MPa(± 5.56), group C 19.57 (± 2.80) and group D 35.62 (± 3.97). Statistical analysis showed a significant influence of the used dentin bonding agent on tensile bond strength (pConclusions: Regarding the limitations of an in vitro study it can be concluded that all self-conditioning dentin adhesives showed promising results. Therefore, the clinical use of self-conditioning adhesive systems might be a good alternative to the established total-etch systems.
Keywords: dentin, dentin adhesive, bond strength, dentin bonding, self-conditioning
Poster 301, Language: EnglishStelzenmüller, Wolfgang/Weber, Dominic/Özkan, Volkan/Freesmeyer, Wolfgang B./Umstadt, HorstThe basic requirement for successfully palpating the lateral pterygoid muscle is exact knowledge of muscle topography and the intraoral palpation pathway. After documented palpation of the muscle belly in cadaverous preparations, MRI and EMG also visualized palpation of the lateral pterygoid muscle in vivo. The palpation technique seems to be essential and basically feasible.
Keywords: TMJ, M. pterygoideus lateralis, EMG, MRI, palpation
Poster 302, Language: GermanGassmann, Georg/Entschladen, Frank/Möller, Sonja von/Grimm, Wolf-DieterIntroduction and Aims: The titanium implant survival rate is due to crevicular peri-implant inflammatory mediatiors from immune competent cells in answer to the subgingival biofilm (Salcetti et al. 1996). CD4+ lymphocytes play an important role in periodontitis (Gemmell et al. 2002). In this study the influence of mono-metal titanium (cp-Ti) as being used in dental implants and of two dental alloys (reduced precious alloy (rpa), palladium based alloy (pba) on activation status and migration of CD4+ lymphocytes is evaluated in a 3-D collagen matrix migration model.
Materials and methods: After immunomagnetical separation of CD4+ lymphocytes harvested from healthy voluntary donors who gave informed consent were incubated in the 3-D collagen matrix migration model with either titanium or one of the alloys (rpa/pba) mentioned. After time-lapse video recording and digitizing the data were analyzed in respect to cell migration. The activation status of CD25- and CD45R0-receptors was evaluated by flow cytometry. Statistical significance was tested applying the Mann-Whitney U-test
Results: Direct contact between CD4+ lymphocytes and alloys resulted in reduced cell migration (rpa:40% reduction, pba: 58% reduction). Titanium led to 11% enhancement (p
Keywords: Dentale Implantate, Legierungen, Biokompatibilität, Migration, T-Helferzellen
Poster 303, Language: GermanSchön, Ralf/Gellrich, Nils-Claudius/Schramm, Alexander/Schmelzeisen, RainerIn dem Zeitraum von Oktober 2000 bis Januar 2002 wurde bei 13 Patienten eine endoskopisch assistierte Versorgung von dislozierten Kollumfrakturen mit Miniplatten durchgeführt.
Material und Methode: Von den 13 Frakturen waren 3 nach medial und 6 nach lateral disloziert. 4 Frakturen zeigten eine axiale Dislokation mit Verkürzung des aufsteigenden Unterkieferastes. 2 Fraktur zeigten ein ausgesprengtes Fragment am Hinterrand des aufsteigenden Unterkieferrandes und bei 8 Patienten waren weitere Unterkieferfrakturen auffällig. Die Frakturversorgung wurde bei allen 13 Patienten über eine intraorale Inzision unter Verwendung von abgewinkelten Bohrern und Schraubendrehern rein transoral durchgeführt. 30° Optiken (Karl Storz, Germany) wurden für die endoskopisch kontrollierte Reposition und Osteosynthese verwendet.
Ergebnis: Unter Verwendung von Endoskopen wurde eine gute Übersicht bei der transoralen Frakturversorgung und Repositionskontrolle insbesondere am dorsalen Rand des aufsteigenden Unterkieferastes erreicht. Postoperative Röntgenbilder zeigten eine regelrechte Reposition. 6 Monate nach Frakturversorgung zeigten die 13 Patienten zufriedenstellende funktionelle Ergebnisse ohne Okklusionsstörungen, mit einer Mundöffnung größer als 40mm ohne Deviation und ohne Limitation bei Laterotrusion.
Schlußfolgerung: Der transorale Zugang mit Gebrauch von abgewinkelten Bohrern und Schraubendrehern bewährte sich als zuverlässige Methode auch bei der Versorgung von dislozierten und mehrfragment Frakturen. Eine Narbenbildung im sichtbaren Bereich und eine Schädigung des N. fazialis wurden bei dem transoralen Zugang vermieden.
Keywords: endoscopic surgery, dislocated condyle fractures, minimal invasive surgery
Poster 304, Language: EnglishStratul, Stefan-Ioan/Rodica, Jianu/Sanda, Enache/Darian, RusuThis is a case report of a 46-y.o. male patient with a history of a sport accident, which resulted in the injury of the upper central incisors. Patient presented years later with localized periodontitis of 11. 9 mm periodontal pocket on the distal and buccal aspect of the root, exudate, root discoloration, mobility of 11 were noticed. Radiographs revealed lacuna on the mid third of the root and 6mm mesial angular defect as measured on radiograph. Vitality tested negative. Root-canal treatment (ProTaper® + Thermafill®plus-Dentsply-Maillefer) was performed. As the attempts to electrometrically assess the root-canal length were inconclusive, a communication of the canal with the exterior was suspected. A full-thickness-flap of the anterior maxillary region was raised. An extensive external resorbtion of the root surface of 11, a deep mesial two-wall defect and lack of the buccal cortical were found. Cavity was filled with glass-ionomer cement, the defect debrided and treated by EMPs (Emdogain®-Straumann) plus bioresorbable membrane. After 18 months pocket reduced to 3 mm, with radiographic defect fill 80%. Conclusions: 1) external root resorbtions can be related to early alveolar injuries. 2) overlooked alveolar injuries can lead to penetrating external root resorbtions complicated with root caries, pulpal necrosis and periodontal defects. 3) therapeutical success can be achieved by combining conservative-endodontic-periodontal procedures
Keywords: root resorbtion, trauma, endodontic-periodontal lesion
Poster 305, Language: EnglishSastravaha, Grindwit/Gassmann, Georg/Sangtherapitikul, Preecha/Grimm, Wolf-DieterCentella asiatica and Punica granatum are medicinal plants that have been reported to promote tissue healing and modulate host responses. Preliminary study revealed positive clinical effects of an innovative preparation from the two herbal extracts in the form of biodegradable chips as a subgingival adjunct to scaling and root planing. The purpose of this research was to evaluate further augmenting efficacy the combined herbal preparation may have among maintenance patients in comparison to standard supportive periodontal therapy (SPT), with additional monitoring of certain inflammatory markers. Fifteen patients in the recall programme who had completed conventional periodontal therapy with remaining probing pocket depth 5-8 mm were enrolled. After baseline examination and collection of gingival crevicular fluid (GCF) samples, SPT was provided and the target teeth in the test group received subgingival delivery of the medicated chips. The clinical parameters which included probing pocket depth (PD), attachment level (AL), bleeding index (BI), gingival index (GI) and plaque index (PI) were recorded and GCF samples were collected at baseline, 3 and 6 months. The results showed significant improvement of PD, AL, GI at 3 and 6 months and BI at 6 months in the test group compared to control. No significant differences in PI were found between the two treatment modalities at all subsequent visits. The test group also showed statistically greater reduction of IL-1ß at both 3 and 6 months and lower IL-6 concentration which almost reached significant level at 6 months. The results indicate that adjunctive local delivery of extracts from C. asiatica in combination with P. granatum significantly improved clinical signs of chronic periodontitis and IL-1ß level in maintenance patients.
Keywords: Centella asiatica, Punica granatum, supportive periodontal therapy, biodegradable chips, subgingival delivery
Poster 306, Language: GermanWeber, Dieter/Mailänder, Thomas/Wangerin, Konrad/Marquardt, BarbaraThe shown "Vario-GNE" allows the orthodontist planning a rapid basic maxillary expansion due to the clinical situation and necessity. It is reserved for cases with need of a different expansion of the anterior and posterior part of the maxilla.Based on the special knowledge and precision these appliance remains a special orthodontist laboratory. Furthermore because of the special application there is a highlevel price. This must be discussed with the patient or the insurance before.The "Vario-GNE" allows the solution of cases which otherwise could not be solved.
Keywords: Vario-GNE, GNE, GNE variabel, GNE chirurgisch unterstützt, Gaumennahterweiterung, RPE, Rapid palatal expansion, Maxillary expansion, RPE surgical assisted, 3-D CT Volume-Rendering.
Poster 307, Language: EnglishSteffen, Wibke/Röhling, Johannes/Bauss, OskarAim: Congenital hypodontia is one of the most frequent anomalies of the human dentition. Several symptoms are considered to indicate a predisposition to congenital hypodontia. The aim of the present study was to examine the prevalence of such symptoms in a group of patients undergoing orthodontic treatment.
Materials and Method: The panoramic radiographs of 968 patients were evaluated. Each radiograph was examined for nine characteristic symptoms: absence of tooth buds, delayed mineralisation of tooth buds, hyperdontia, atypical position of tooth buds, microdontia, displaced teeth, taurodontism, increased distance between molar buds (only for permanent teeth) and infraposition of the primary molars.
Results: Three hundred patients (31%) were found to have one or more symptoms of a disturbed development of the dentition. The most frequent symptoms were atypical position of tooth buds (15.5%), displaced teeth (10%), and the absence of buds for permanent teeth (7.5%). Seventy-two per cent of the patients had only one symptom and 28 per cent two or more. Displaced teeth were associated more frequently than aplasia with other symptoms. All other symptoms were found significantly (PConclusions: The initial detection of symptoms of a disturbed development of the dentition suggests that further developmental disturbances are likely to be encountered to some degree. Early recognition of those symptoms allows early application of preventive orthodontic measures.
Keywords: disturbed odontogenesis, panoramic radiograph, hypodontia, hyperdontia, tooth displacement
Poster 308, Language: EnglishPohl, Yango/Filippi, Cornelia/Kirschner, HorstHealing following replantation of avulsed teeth is dependent upon short unphysiologic periods during the extraalveolar phase. A commercially available tooth rescue box (Dentosafe®) was developed and distributed at schools in Hessen, a state in Germany. Aim of the study was to evaluate the availability times of rescue boxes and the storage periods of rescued teeth within the boxes. Two thousand one hundred tooth rescue boxes together with a questionnaire were distributed predominantly at schools. In case of usage of a box the questionnaire should be filled out by patients and dentists and sent back for evaluation. One hundred seventy two (8.2%) questionnaires were sent back. Eighteen questionnaires were incomplete. In the remaining 154 tooth rescue boxes, a total of 201 avulsed teeth and tooth crown fragments were rescued. When accidents occurred near a stored rescue box the availability time was short (median: 5 minutes). It was significantly longer (median: 40 minutes) when the location of the accident was distant to a stored box. Storage of avulsed teeth in the tooth rescue box was longer (median: 2 hours) than storage of fractured crown fragments (median: 1 hour).Lay people (teachers, pupils) used the rescue boxes correctly without professional help or even advice by telephone. The usage of the tooth rescue box seemed to be self-explanatory and plausible to lay persons, very short availability times resulted when accidents occurred near stored boxes. Thus, an excellent healing prognosis can be anticipated after replantation. The storage periods of avulsed teeth before the commencement of treatment exceed by far the periods that are acceptable for alternative but unphysiologic media (saline, saliva, milk). It is concluded that tooth rescue boxes should be distributed at locations prone to tooth traumas (schools, kindergartens, sporting facilities, public pools) to enhance the prognosis of avulsed teeth. Emergency units (hospitals, ambulances) should be equipped with tooth rescue boxes as well as every dentist. Tooth rescue boxes are recommended for families with children.
Keywords: tooth avulsion, tooth rescue box, storage medium, tooth rescue, tooth replantation, healing complications, ankylosis, replacement resorption, prevention
Poster 309, Language: EnglishKlinke, Thomas/Zraiki, Samira/Klimm, Wolfgang/Viergutz, Gabriele/Kuhlisch, Eberhard/Gente, MichaelCaries detection at non-cavitated occlusal sites remains challenging. The present investigation deals with the suitability of four methods to detect dentine caries when fissure discolouration occurs:
(1) visual inspection with magnifying glasses using modified Ekstrand criteria,
(2) laser fluorescence measurement with KaVo DIAGNOdent device,
(3) electric conductive measurement with ECM III,
(4) electric conductive measurement with Cariometer CRM 800 (Gente, M., 1999, unpublished).
A total of 550 sites were examined in vivo. To attain a gold standard, a minimal-invasive opening of this site was performed, if two or more methods indicated dentine caries. Lesion depth was determined visually and dentine softening as an indicator for caries activity was assessed with a dental probe. This way validated data were collected at 108 sites that were opened in the fissures of 60 teeth from 37 patients aged 6 to 16 and 17 to 30 years. ECM showed the highest performance in younger patients followed by Cariometer, DIAGNOdent and visual inspection (sensitivity/specificity/AUC 0.97/0.91/0.97, 0.82/0.82/0.93, 0.67/0.85/0.78 and 0.82/0.48/0.65). Compared with all dentine lesions, the detection of soft dentine lesions was less accurate for ECM and Cariometer (AUC 0.88, 0.82, 0.78 and 0.62). For older patients (17 - 30 years) the diagnostic performance of all methods decreased considerably (AUC 0.66, 0.53, 0.56 and 0.51). In conclusion, among the four methods used, ECM demonstrated the best suitability for dentine caries detection at non-cavitated, discoloured occlusal sites. The small and convenient Cariometer also proved to be a usable tool.
Keywords: dental caries, dental fissures, diagnosis, diagnostic techniques and procedures
Poster 310, Language: EnglishGrimm, Wolf-Dieter/Gassmann, Georg/Kübler, Steffen/Engler-Hamm, Daniel/Jackowski, JochenIntroduction: In order to improve the longevity of implants and to achieve esthetically more satisfying results, it has been proposed to place implants with their border between the rough and smooth surfaces below the level of the alveolar crest, thereby obtaining a submucosally located implant shoulder following healing. The aim of the present retrospective clinical study was to clinically and radiographically evaluate the tissue response to the placement of one-stage transmucosal implants with the border between the rough and the smooth surfaces sunk into a subcrestal location.
Material and methods: In total, 84 ITI, 13 Brånemark and 5 Type Frialit-2 (n = 102) implants were included in the study. Probing bone levels (DIB), gingival inflammation (GI) and plaque index (PI) were recorded at 2 years, at 3-4 years, and at 5-7 years. Periodontal probing depth (PPD), "attachment" levels, width of keratinised mucosa, distance from the implant shoulder to the marginal mucosa (DIM), the sulcus fluid flow rate (Periotron, Harco, Winnipeg, Canada), and radiologic bone loss over time were measured at the same time intervals. All parameters were assessed at 4 sites around each implant. The mean for each implant was calculated and used for analysis. The Wilcoxon matched pairs signed rank test and the Student t-test were applied to detect differences over time.
Results: Results showed an overall success-rate of 97.1%. Expected correlations between GI and PI, the sulcus fluid flow and the amount of gingival inflammation (GI), PPD and the amount of angular bone-loss were found to be significant. All implants lost a significant amount of clinical bone height during the first 2 years (1.57 mm, p = 1. Keratinised mucosa was found to decrease over time. Tendencies to increased PPD could be seen when only a small amount of keratinised mucosa was present. This could be associated with the formation of the biological width around dental implants.
Conclusion: In addition to the crestal bone resorption occurring at implants placed under standard conditions, the bone adjacent to the polished surface is also lost over time. From a biological point of view, the placement of the border between the rough and the smooth surfaces into a subcrestal location should not be recommended.
Keywords: longevity of implants, retrospective clinical study, periodontal tissue response, radiologic bone, one-stage transmucosal implants loss, subcrestal placement of implants