International Poster Journal of Dentistry and Oral Medicine, 03/2006

Accurate transfer of computed tomography (CT) based planning of dental implants into the surgical procedure, using a surgical template with integrated customized drill guide. By means of a multiplanar reconstruction of the patient's dental CT scan the future implant site was determined. This was accomplished by marking entrance and endpoint of the required osteotomy within the CT scan. During the CT scan as well as during surgical implant insertion a mount with radiopaque markers, attached to a vacuum-formed diagnostic template, was inserted into the patient's mouth. The markers were used to locate the mount within the CT. According to the CT-data based coordinates of the future osteotomy our software created a computer aided design (CAD) system macro. The macro defined a matching component part with integrated drilling duct, which could be inserted into the mount. This part was manufactured by means of stereolithography and completed with a titanium tube, to guide a pilot drill with a diameter of 2 mm. The osteotomy was then widened to insert the dental implant. Application to phantoms resulted in an accuracy better than 0.5 mm in the direction of the CT sections and better than 1 mm perpendicular to them. The method was successfully applied to provide a patient with two adjacent implants. Keywords: accurate implant placement, surgical template for dental implant, planning of dental implant surgery, CAD-CAM template, drill guide

In tissue engineering the use of 3D scaffolds is getting more important. Especially in maxillo facial surgery there is a variety for using special supporting stability materials for calvarium reconstruction, sinus floor evaluation and tumor surgery.In the following in vitro studies we compared a rapid prototyping produced scaffold with an industrial produced material which is covered with 10 % collagen fibres. The technique of rapid prototyping allows an individual 3D produced scaffold. We used PLGA by rapid prototyping methods to reach a high stability. Both maerials were seeded with 1 x 105 osteoblasts. The cells were cultivated out of pieces of corticolamellar bone of the maxilla from five different patients and five sheeps. After one week in the cell incubator cell proliferation test (EZ4U) was done. Furthermore cell growing was investigated by using scanning electron microscope.Comparing these experiments the human osteoblasts showed a higher cell proliferation than the sheep osteoblasts. Only a small difference between the two materials was seen.The test showed that both materials are equal with regard to cell proliferation and cell cytotoxicitity. There are suitable for clinical surgeries. The advantage of rapid prototyping is the possibility of making individual forms. Keywords: tissue engineering, rapid prototyping, scaffolds

Die nekrotisierende Sialometaplasie ist eine gutartige, reaktiv-entzündliche Erkrankung der kleinen Speicheldrüsen des Gaumens, die erstmals 1973 von Abrahams beschrieben wurde. Im Frühstadium liegt meist eine umschrieben Schwellung vor, die innerhalb von wenigen Tagen ulzeriert. Häufig geht ein Infekt oder ein Trauma im Kopf-Hals-Bereich voraus. Die Ätiologie ist noch nicht abschließend geklärt. Im Mittelpunkt der Diskussion steht eine Schädigung auf vaskulärer Ebene mit zumeist unklarer Genese. Aus dieser lokal eingeschränkten Blutversorgung resultiert ein Infarkt. Histologisch zeigt sich eine Nekrose des lobulären Speicheldrüsenparenchyms, gangähnliche und streckenweise tumorartige Plattenepithelmetasplasien.Therapeutisch ist keinerlei Intervention notwendig. Die Ulzerationen heilen spontan innerhalb von 8 bis 12 Wochen ab.Die nekrotisierende Sialometaplasie kann klinisch und histologisch einen malignen Prozess vortäuschen. Daraus können sich erhebliche differentialdiagnostische Schwierigkeiten ergeben. Fehlinterpretationen, insbesondere als Plattenepithel- oder Mukoepidermoid-Karzinom, mit der Folge einer invasiven Behandlung sind mehrfach in der Literatur erwähnt. Für den Kliniker und Pathologen ergibt sich hierdurch die Notwendigkeit der Kenntnis dieses seltenen Krankheitsbildes, um diagnostische und therapeutische Irrtümer zu vermeiden. Keywords: Nekrotisierende Sialometaplasie

The clinical picture and treatment of a life threatening necrotizing fasciitis in a 53 and 75 year old patient is presented.In both patients a descending phlegmonous spread of infection sternally and ß-hemolytic pyogenic streptokokki were demonstrated in blood cultures. In the patient 53 years of age the necrotizing fasciitis was located in the area of the left eye lids. Intensive care was indicated due to septic complications and a beginning cardiac shock syndrom. CT and sonographic evaluation showed reactive swelling of the eyemuscles and phlemonous changes of the soft tissues in the head and neck from left temporal to parasternal region without signs of abscess formation. In the patient 75 years of age with the history of Diabetes mellitus the CT demonstrated extended necrosis and air filled cavities cervical to sternally. As origin of the infection a decaded lower right first molar was suspecetd. Due to the swelling the air way was compromised and endotraceal intubation was indicated in the septic patient.Following antibiotic therapy only a recoverey was noted in the 53 year old patient. Parameters of inflammation were normal after 6 days.In the 75 year old patient immediate surgical debridement and abscess drainage was performed in combination with a perioperative antibiotic therapy. Day post surgery the WBC decreased from 13,8 Tsd/µl to 9,5 Tsd/µl. Extubation was performed at postoperative day.In both patients a good recovery was noted. Conclusion: A surgical intervention and antibiotic treatment only demonstrated satisfying results in the treatment of necrotising fasciitis of the head and neck. Keywords: nekrotisierende Fasciitis

This is a case report of a 26-y.o. female patient with history of sport accident which caused in time, by recurrent misdiagnosed apical infections, the loss of tooth 22 and its buccal cortical plate. Loss resulted in impressive inesthetic alveolar defect (cca. 20x15 mm) that discouraged prosthodontic attempts to restore the edentation. Radiographs showed complete lack of the buccal cortical plate and extended circular lacuna of the palatal cortical plate, which turned the apparent buccal defect into an extended trough-and-trough crestal defect. Buccal and palatal flaps were raised, the lack of the buccal plate and the circular lacuna of the palatal plate were confirmed. A rectangular cortical block was harvested from the chin, adapted and fixed to the thin palatal bony bridge by mean of special suture loop. Graft was completed with a combination of autologous bone chips and TriCalciumPhosphate, flaps were repositioned. 4 months after, alveolar crest showed good dimensional stability and satisfactory esthetic appearance. Radiographs displayed slight resorbtion of the graft. Conclusions: 1) misdiagnosed traumatic events of upper incisors can lead to extended trough-and trough crestal defects. 2) treatment by bone grafting with autologous cortical chin blocks can be a predictable alternative to the GBR with reinforced membranes. Keywords: crestal defect, autologous chin graft, TCP

Objective: Report of clinical and microbiological periodontal findings before and six months after treatment of two siblings with Papillon-Lefèvre syndrome (PLS). Methods: Two brothers, RG 3 and NG 5 years of age, were referred for treatment due to premature mobility of their deciduous teeth. Probing depths (PPD), attachment levels (PAL-V), and furcation involvements were examined clinically. Panoramic radiographs were taken. Subgingival plaque samples within the deepest pocket of each tooth were taken and analyzed by real-time PCR for Actinobacillus actinomycetemcomitans (AA), Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Fusobacterium nucleatum, and Prevotella intermedia. One-stage full-mouth scaling and extraction of hopeless teeth were performed under general anesthesia, followed by systemic amoxicillin and metronidazole for seven days. Clinical and microbiological analyses were performed six months after treatment. Results: Before treatment, both siblings had exhibited PPD of up to 13 mm, Class III furcation defects at four teeth, and marginal suppuration. AA was detected in both patients and at all teeth at levels ranging from 3.0 × 102 to 5.1 × 106. Both patients exhibited palmar and plantar hyperkeratosis. Seven teeth were extracted from RG, nine from NG. Six months after treatment, PPD had been reduced to £ 5 mm. AA was not detected in any of the remaining teeth. Conclusion: Even periodontally affected deciduous teeth of PLS patients can be treated successfully. Suppression of AA to below detection level seems to be of high significance. Keywords: Papillon-Lefèvre-Syndrom

In maxillo-facial surgery bone substitutes are used in clinical routine in sinus floor elevation and defect reconstruction. Reconstruction with tissue engineered bone needs a 3D structured biomaterial which can be also a bone substitute. In this study we wanted to optimize the cell adhesion and growing onto one commercial available bone substitute of bovine origin. The bone substitute has an osteconducvtive mineral structure. Additionally we used the same material with a covering of 10 % collagen fibres. Both materials were normally adjusted in its native state without any cell complement. Evaluations of these two materials on its tissue engineering properties were made. We distinguished from treated and untreated matrices. In the first experiment the materials were put into a culture medium over night without any prehandling. After 24 hours 1 x 105 cells were seeded onto the materials. Parallel in the second experiment the materials were put in a perfusion culture for 48 hours. 1 x 105 Osteoblasts were seeded. We divided into two groups and put one of it into a vacuum exicator for 1 minute. Both groups were put into the CO2 cell incubator like in the other experiment. After one week the evaluation was made with cell proliferation tests (EZ4U) and the cell colonization was investigated with scanning electron microscope. Additionally we compared sheep and human osteoblasts for these experiments. As conclusion there was different adhesion and growing pattern of the osteoblasts. The best results were found in the perfusion chamber combined with the vacuum treatment and worst results without prehandling. Keywords: tissue engineering, growing, rapid prototyping

The interdependence of inner architecture of bone and its functional loading is one of the fundamental principles of Biomechanics. Our objective is to demonstrate this interdependence for the case of a human mandible by qualitative correspondences of a 3D-profile representing the organ's inner structure and simulated volumetric strain. We simulated a lateral bite on the leftmost premolar of a partially edentulous human mandible characterized by beginning atrophy of the alveolar ridge. By means of visualization techniques developed by the group, a volumetric profile of bone mineral density based on CT numbers could be given. We compared regions of elevated volumetric strain with regions of elevated tissue density and vice versa. Notably, dominant compression besides the biting tooth corresponds to the atrophied region there. Keywords: human mandible, finite element simulation, biomechanics, inner architecture of bone, inner structure visualization

The ELSPAC project (European Longitudinal Study of Pregnancy and Childhood) organized by WHO has been conducted in several European countries including the Czech republic aimed at identifying the features of the lifestyle and environmental conditions beneficial to the health of mothers and children. The aim of the present study is to gather oral health data of children from the ELSPAC group monitored in the city of Brno. Randomly selected children (ELSPAC) (n=83) were clinically examined for dental and periodontal status, dental plaque and orthodontic anomalies and the means of the DMFT score and components, Restorative index, treatment need and the prevalence of orthodontic anomalies were calculated. Data obtained were compared with those of the countrywide survey (CWS) of 12 (n=316) and 15 yr-olds (n=352) in 2003. Statistical processing: linear extrapolation of both age groups from CWS to 13 years; differences between ELSPAC and CWS tested by Student T-test and Fisher exact test (P=0.05). ELSPAC vs. CWS: age- 13.14, 13.14 (NS); DMFT- 2.25, 2.80 (NS); DT- 0.33, 0.34 (NS); RI (%)- 81.6, 85.0 (NS); caries free (%) 30.1, 26.9 (NS); at need of restorations (%)- 7.2, 20.6 (P Keywords: Elspac study, dentistry, caries experience, gingivitis, oral epidemiology

Objectives: The purpose of this study was to determine the influence of experimental demineralization on microtensile bond strengths of three different self-conditioning adhesive systems (Adper, AdheSE, Clearfil Protect Bond). Methods: Seventy-two freshly extracted third molars were included. All teeth were specially prepared allowing the simulation of dentin perfusion. Dentin specimens with a total thickness of 3.5 mm were obtained under standardized conditions. The specimens were randomly assigned to six experimental groups. In three groups (AD, BD, CD) the prepared dentin surface was demineralized using acified gel technique (HEC, pH 4.8, 37°C) for 14 days. Group A, AD: Adper; group B, BD: AdheSE; group C, CD: Clearfil Protect Bond. All materials were applied on a standardized surface area 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 (Clearfil APX, colour A2) using an universal testing machine. Statistical analysis was performed using SPSS 10.0. Results: For the six test series following microtensile bond strengths were evaluated (mean value and standard deviation in MPa): group A 21.93 (± 3.19), group AD 11.39 (± 5.58), group B 17.65(± 5.50), group BD 5.75 (± 2.35), group C 21.99 (± 3.56) and group CD 15.09 (± 7.26). 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 demineralization of dentin might decrease bond strength of self-conditioning dentin adhesives. Keywords: demineralisation, bond strength, dentin adhesive