International Poster Journal of Dentistry and Oral Medicine, 01/2005

Objectives: Former investigations have shown that dentin adhesives can prevent root surface caries. The aim of the present study was to determine the caries-protective effect of a dentin bonding system on sound and irradiated root surfaces in vitro. Methods: The root surfaces of 30 freshly extracted caries-free human molars were thoroughly cleaned, thereby removing the cementum. Fifteen teeth were irradiated. The irradiation dose of 60 Gy was fractionally applied over six weeks (2 Gy/day). The teeth were then coated with acid-resistant nail varnish, exposing two rectangular windows. One window served as an untreated control, while the other window was treated with a dentin adhesive (One-Coat-Bond). The specimens were distributed among the following experimental groups: A: irradiated, treated with dentin adhesive; B: irradiated, not treated; C: non-irradiated, treated; D: non-irradiated, not treated. All specimens were demineralized for 6 days with acidified gel (HEC, pH 4.8, 37 degrees C). From each tooth, two dentinal slabs were cut. The depth of the demineralized areas was determined using a polarized light microscope. Results: The coated, irradiated specimens in group A showed lesions with a mean depth of 63 µm (± 11 µm). In group B lesion depth was increased (91 µm ± 6 µm). The non-irradiated specimens in group C and D showed a mean lesion depth of 58 µm (± 14 µm) and 92 µm (± 7 µm). In group A and C the lesion depth was reduced significantly compared to the untreated groups B and D, the comparison of group A and C and between B and D showed no significant differences (pConclusion: It can be concluded that the demineralization of the root surface can be impeded by application of the dentin adhesive tested. In the present study no differences between irradiated and sound root surfaces could be detected. Schlagwörter: dentin adhesive, root caries, irradiation, demineralization, dentin

Objective: Evaluation of tooth-related factors influencing long-term success of systematic periodontal therapy. Main outcome variable for this analysis was tooth loss. Methods: 38 patients were consecutively recruited. Inclusion criteria were antiinfectious therapy 10 years ago by the same therapist (PE) and a complete set of intraoral radiographs obtained at the initiation of therapy. Clinical examinations, sampling for interleukin-1 polymorphism test, and questionnaire regarding smoking, and oral hygiene, were performed by the same examiner (BP). Tooth loss, type, and location as well as frequency of supportive periodontal therapy (SPT) were recorded from patients' charts. Each tooth was evaluated for bone loss in per cent of root length and type of bone loss (vertical/horizontal) on the radiographs by another examiner (JK). Results: From a total of 847 teeth 70 teeth were lost in a period of 10 years (8%). Initially 256 teeth exhibited a bone loss up to 20% (tooth loss 4%), 302 up to 40% (5%), 192 up to 60% (11%), 69 up to 80% (19%), and 28 > 80% (36%). Under frequent SPT (21 patients, 479 teeth) tooth loss amounted to 4%, without SPT to 13%. Multilevel regression analysis identified the following factors as preventive against tooth loss: frequent SPT (p = 0.021), little bone loss (p Conclusion: Little initial bone loss, mandibular as well as anterior tooth location, and frequent SPT are positive predictors for tooth retention. Schlagwörter: Langzeitergebnisse, antiinfektiöse Therapie, unterstützende Parodontitistherapie, parodontaler Knochenabbau, Zahntyp

The aim of this study was to compare the results of a microbiological test from 3 different sites with the results from all three samples pooled in one transport vial. 27 patients suffering from aggressive periodontitis or generalized severe chronic periodontitis participated in this study. Clinical examinations were obtained before (n=10) or after (n=19) antiinfectious periodontal therapy. Microbiological samples were obtained from the three pockets with the deepest probing depths for microbiological analysis. Two sterile paper points were inserted simultanously in the periodontal pockets. One paper point from each pocket was put in a separate transport-vial, the other was pooled (MT3) with the two other paper points of a respective patient in a transport-vial and analysed for Actinobacillus actinomycetemcomitans (AA), Tannerella forsythensis (TF), Porphyromonas gingivalis (PG) and Treponema denticola (TD) with a commercially available RNA-probe test. The logarithmic bacterial load of pooled samples was for all tested bacteria higher than the mean value of the results of the single samples. For TF (p Schlagwörter: generalisierte schwere chronische Parodontitis, aggressive Parodontitis, subgingivale Plaque, mikrobiologischer Test

All-ceramic dental restorations get an impact in prosthodontic therapy concepts due to their esthetic advantage and their excellent biocompatibility - which are the main prerequisites to meet the demands of patients nowadays. However, glass ceramic needs an adhesive cementation to reinforce its weak strength. The limited indication to veeners, inlays, onlays and anterior single crowns caused a long-term success proven by several clinical trials. An "add on" of these indications are now possible by using frames of high tech ceramic zirkonia. The so called "ceramic steel" can be used for three or more unit fixed partial dentures (FPD's) even in the posterior regions. Additionally the high strength and fracture resistance of zirconia provides a thin thickness of crown- and bridge frameworks causing a minimal invasive shape of a tooth preparation. Even ceramic implant abutments and conical taper crowns show an increased survival rate compared to other all ceramic systems. Unfortunately zirkonia can be only processed by a CAD/CAM based milling machine. To prevent grinding the very strong zirkonia bulk, the pre- or semi-sintered zirkonia, is milled in a 30% enlarged three dimensional form to compensate the shrinkage in the post process of sintering. This procedure saves costs and will offer the replacement of standard porcelain fused to metal restorations by all ceramic single crowns and FPD's in the near future. Schlagwörter: dental, all-ceramic, CAD/CAM, fixed partial denture, FPD, fused to metal restorations, PFM, esthetic, aesthetic, biocompatible, zirconia, Semi sintered, hot isostatic pressed, embriddlement, flexural strength

The chin as facial landmark deserves a special attention in the course of orthognathic surgery. As an additional procedure genioplasty may be indicated to obtain an optimal functional and aesthetic outcome.Aim of the present study to evaluate different indications, healing process and the results.During a 15 year period a total of 35 patients out of all 305 orthognathic patients underwent a genioplasty according to the Hofer procedure. The indication were as follows: 16 cases a mandibular hyperplasia, in 10 cases a mandibular hypolplasia, in 9 cases a frontal open bite.In only 4 cases the genioplasty were performed a single procedure, in 16 patients it was combined with a bilateral sagittal mandibular split, in 7 patients with a bimaxillary procedure and in 5 patients with a Le-Fort-I-osteotomy or segmental osteotomy. The osteotomy sites were stabilised with miniplates and miniscrews respectively. Minor healing problems were observed in 5 patients which were managed by local measurements only. A set-back was performed in 16 patients, a set-forward in 10 and reduction of the vertical dimension in 12 patients. Neurosensory disturbance were only found in 2 patients after 12 month follow-up.Based on the data one can conclude that the autologous genioplasty is an easy, cost-effective surgical procedure with low complication rate in order to achieve a facial harmony. Schlagwörter: Genioplastik, Dysgnathiechirurgie

An Astra-Tech-Universal implant with a combination of macro- and micro-thread in a single-stage procedure has been applied for prosthetic treatment of the toothless maxilla with a permanent reconstruction in four international centres. The design of the implant corresponds to the Astra-Tech single-tooth implant, which has been on the market since the late 80s. During the healing phase of six months, 22 of the 374 implants were lost, i. e. the survival rate was 91.2%. Evidently, shorter implants have a much higher loss rate than longer ones. The initial loss rate was significantly higher in smokers (12.7%) than in non-smokers (4.1%). No further implants were lost during the 24-months long controls. In the course of the load duration, a slight consolidation of the marginal bone level by means of a reduction of the distance between marginal bone level and reference point shows after a relatively large initial bone loss of 1.43 mm during the healing phase. The results regarding the initial bone loss rate correlate with other reports about implants with single-stage procedure in the toothless maxilla. The reconsolidation of the marginal bone level is consistent with the increase of the secondary stability of 2.45 ISQ units that was measured by means of resonance frequency analysis (RFA) in Astra Tech implants in the maxilla. The application of the single-stage procedure technique following the protocol as mentioned in material and methods leads to an average initial bone loss of 1.80 mm (measured from the reference point) which is markedly higher than the bone loss after applying the two-stage technique (0.2 mm) with the same type of implant. Therefore, it is not to be recommended to apply the single-stage procedure with an immediate reinsertion of the soft relined full denture in the toothless maxilla. Smokers, in which the single-stage procedure is applied, have to reckon with a significantly higher implant failure rate than non smokers. Schlagwörter: single-stage procedure, toothless maxilla, implants with micro- and macro-threads, Astra Tech Implants

The ethiology and pathogenesis of caries are multifactorial in which the local immune defence of the oral cavity plays a pivotal role. In this context the participation of cytokines may be important in the regulation of local immune reactions. The aim of the present study was to investigate the relation between cytokines in saliva and caries. Unstimulated saliva was obtained from 58 children (33 female, 25 male) aged 8-10 years in the frame of a dental examination. The caries incidence was 44,8 % (26 children). The cytokines determined were interleukin-8 (IL-8), interleukin-1 beta (IL-1 beta) and tumour necrosis factor alpha (TNF alpha). In addition the soluble tumour necrosis factor receptor II (sTNF RIl) and the complement component C3a were measured. The concentrations of all saliva parameters were measured by enzyme-linked immunosorbent assays (ELISA). The concentrations of examined saliva parameters showed great interindividual variability, however mean values of children with caries showed higher values being significantly for IL-8. Correlations between the cytokines were significantly positive for children with or without caries. Oral hygiene and kind of filling material (plastic fillings) showed significant negative correlations with sTNF RII and TNF alpha, respectively. For IL-8 a significant positive correlation was found in relation to caries. The increased concentrations of factors of the local immune defence in saliva of children with caries indicate an enhanced local immune activity within the oral cavity. According to the positive association between the chemoattractant IL-8 and caries it is assumed that IL-8 plays a role in the development and progression of caries. Schlagwörter: saliva, cytokines, caries, Speichel, Zytokine, Karies

Advancements in cancer research have led to the innovation of contemporary diagnostic tools for early oral cancer detection. Vizilite® and Glowsticks based on the principle of 'chemiluminescence' and Light Emitting Diodes (LED) are the latest diagnostic tools available for this purpose. Objectives: To evaluate the potential value of chemiluminescence (Vizilite® and Glowsticks) and LED as tools for the early detection of oral cancer, dysplasia and potentially malignant epithelial lesions (PMEL). The efficacy of these tools was assessed in terms of sensitivity, specificity and accuracy. Methods: A sample of 67 high-risk individuals aged 35 years and above were selected. Their inclusion criteria were history of habits including smoking, alcohol consumption or betel quid chewing, with presence of primary squamous cell carcinomas (SCC), previously treated SCC or PMEL. The study was conducted in two phases. During the first phase of the study, Vizilite® was assessed on 40 subjects. In the second phase, Glowsticks and LED were assessed on 27 subjects. Biopsies were performed on identified lesions in 37 subjects. Another 14 subjects had no lesions. In the remaining 16 subjects, a biopsy was not performed due to subject's ill-health. The biopsy findings were correlated with the clinical observations. Results: The sensitivity was 100% for all three diagnostic tools whereas the specificity was higher for Glowsticks and LED (90%) than for Vizilite® (85.7%). The accuracy was marginally higher for Vizilite® (96.8%) compared to the other two (95%). Conclusions: Chemiluminescence and LED are effective in the early detection of oral cancer, dysplasia and PMEL. The LED may prove to be cheap, safe and non-invasive tool for screening high-risk individuals in clinics, health centres and remote areas devoid of modern healthcare facilities. Schlagwörter: oral cancer, chemiluminescence, vizilite, glowsticks, LED

Objectives: The aim of the present study was to evaluate the influence of a densensitizer (Gluma Desensitizer) on tensile bond strength of different dentin adhesives. Methods: Sixty freshly extracted third molars stored in saline for a maximum of seven days after extraction were included in this study. 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 four experimental groups: group A1: Clearfil New Bond/ Clearfil Core; group A2: Gluma Desensitizer/ Clearfil New Bond/ Clearfil Core; group B1: Xeno III/ Tetric; group B2: Gluma Desensitizer/ Xeno III/ Tetric. All materials were applied as recommended by the manufacturer. Tensile bond strength of the above mentioned bonding agents was measured 15 minutes after application and light curing of the composite material (colour A2) using an universal testing machine. Results: For the four test series following tensile bond strengths were evaluated (mean values and standard deviations in MPa): Group A1: 12.59 (± 4.65), group A2: 12.50 (± 5.26), group B1: 4.46 (± 1.38), group B2: 6.60 (± 1.23). Statistical analysis showed a significant influence of the used dentin bonding agent on tensile bond strength (pConclusions: Within the limitations of an in vitro investigation it can be concluded that the pretreatment of dentin using a desensitizer might not affect tensile bond strength of the dentin adhesives tested. Schlagwörter: bond strength, dentin, dentin adhesive, desensitizing

Objectives: The objective of this study was to evaluate the onset of initial demineralization in human dentin pretreated either with two different dentin bonding agents or a desensitizer. Methods: Twenty-eight freshly extracted human molars were included in this study. The root surfaces were thoroughly cleaned, thereby removing the cementum. From each tooth four root dentin specimens were prepared. The specimens were distributed among the following experimental groups: A: Syntac Classic, B: XenoIII, C: Hyposen, D: control group, untreated. One dentin specimen of each group was inserted into both buccal aspects of each fourteen intraoral mandibular appliances. The appliances were worn by fourteen persons 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. During meals, the appliance was stored in 10% sucrose solution. After the in situ period, slabs (150 microns) were ground and studied using a polarized light microscopic. Results: Concerning lesion depth, ANOVA revealed significant differences between brushed and unbrushed specimens. In the brushed groups following lesion depths were evaluated (mean values and standard deviation in microns): Group A: 27.6 (±9.6); group B: 28.7 (±9.6); group C: 34.3 (±20.6); group D: 74.1 (±18.5). The unbrushed specimens showed following lesion depths: Group A: 59.9 (± 13.1); group B: 52.5 (± 12.1); group C: 72.9 (± 19.9); group D: 101.7 (±23.9). Compared to the untreated control, lesion depths in group A, B and C were significantly decreased in the brushed and also in the unbrushed subgroups (pConclusions: Within the limitations of an in situ study it can be concluded that the demineralization of the root surface can be impeded by application of dentin adhesives and desensitizers under different oral hygiene conditions. Schlagwörter: root dentin, sealants, adhesives, demineralization

Objective: The aim of the present study was to evaluate the marginal adaptation of class II restorations after using two different dentine bonding agents in vitro. Methods: Sixty freshly extracted human molars, free from any cracks, caries or restorations were used. To simulate the clinical situation as closely as possible, during restorations placement, teeth were imbedded in a model of plaster and put in a phantome head. In the mesial and distal part of each tooth a standardized class II cavity was prepared. The cervical margin was located 0.5mm below the cemento-enamel-junction. After having completed all preparations, the teeth were randomly assigned into four groups with fifteen teeth each. Group 1: Excite/ Tetric; group 2: Excite/ Tetric/ Tetric Flow; group 3: Xeno/ Spectrum; group 4: Xeno/ Spectrum/ X-Flow. Metall matrix bands and cervically wedges were placed. All materials were applied according to the instructions of the manufacturer and light cured. All teeth were then subjected to 1150 thermal cycles (5°C-55°C). All specimens were stored for 24h in methylen blue and penetration depths were measured under a light microscope. Results: For the four experimental groups following penetration depths were evaluated (mean values and stadard deviations in microns): Group 1: 4145 (± 604); group 2: 3492 (± 593); group 3: 4161 (± 782); group 4: 2872 (± 1748). Statistical analysis showed a significant influence of the different material combinations (ANOVA, pConclusions: Within the limitations of an in vitro investigation it can be concluded that the use of flowable composites might improve marginal adaption in class-II-restorations. Schlagwörter: flowable composites, class-II-restorations, marginal adaptation, dentin bonding agent

Objectives: Xerostomia is one side effect after radiotherapy of malignant tumors in the head and neck region. Therefore, the aim of this study was to determine the influence of parotid-sparing radiotherapy on salivary flow rate and quality in irradiated patients. Methods: 32 patients receiving parotid-sparing radiotherapy were included. The patients received either a mean dose of 20-35 Gy (11 patients, group A), 35-50 Gy (11 patients, group B) or 50-65 Gy (10 patients, group C). Stimulated saliva was evaluated in regard to salivary flow, buffer capacity, colonisation with Streptococcus mutans and Lactobacillus before, three weeks after beginning and four weeks after the end of radiotherapy. Results: The mean stimulated salivary flow rate of all patients was 0.78 ml/min before radiotherapy. After three weeks the stimulated saliva flow was decreased in all groups. At this point no significant differences between the three groups could be observed. Patients receiving a mean dose below 35 Gy showed a salivary flow of 0.47 ml/min (60.3% of baseline) 4 weeks after irradiation. Increasing the mean parotid dose to 35-50 Gy and 50-65 Gy resulted in a significantly higher decreased flow rate of 0.17 ml/min (21.8%) and 0.15 ml/min (19.2%) compared to group A. Between group B and C no significant differences could be detected. The buffer capacity in group A retained at baseline level, while in group B and C a reduction could be observed. The colonisation with Streptococcus mutans and Lactobacillus varied little in all groups over the whole period. Conclusions: The results demonstrate that parotid-sparing radiotherapy has a significant influence on salivary flow. Patients treated with mean parotid gland doses lower than 35 Gy showed significant higher salivary flow compared to both other groups. Therefore, a mean parotid gland dose of at least less than 35 Gy might be desirable in radiotherapy planning. Schlagwörter: radiation, parotid gland, salivary flow rate

The demand of the patient for a quick and reliable procedure request the predictability for immediate loaded implants. The aim of this prospective study was to evaluate the clinical performance of immediate loading of dental implants. Between 1999 and 2001 210 XiVE screw-type implants with a grit-blasted and acid-etched surface were consecutively placed in 62 patients and immediate loaded having a placement torque of minimum 35 Ncm. 186 were placed in the mandible and 24 in the maxilla. Most of these implants were inserted in the interforaminal area of the mandible (172 implants) and restored immediately with a bar and overdenture. 31 implants mainly in the esthetic area of the maxilla were immediately restored but without functional loading (out of occlusion), most of them for single-tooth restoration. After a follow-up of 12 to 36 months (average 27.3 months) 2 implants failed in the edentulous mandible, both during the first 2 months of loading. All other implants are still in function with acceptable peri-implant parameters. Bone loss > 3 mm was observed in 6 implants placed in the edentulous mandible. The 31 non-functionally loaded implants osseointegrated and were restored with a functionally loaded ceramic crown 3 months after implant placement. Peri-implant probing depth and bone loss showed no significant difference between functional and non-functional implant loading. The data and the experience described of this 3-year analysis indicate that immediate loading of implants using appropriate surgical and restorative techniques can be a predictable technique for shortening dental rehabilitation time with relevant satisfaction for patients in restricted indications. Immediate restoration of implants in the esthetic area without functional loading seems to be a successful method in cases of implants with a high primary stability. Schlagwörter: immediate loading, XiVE, augmentation, three-year-result

Correction of the facial skeletton in case of severe deformities or malformations needs detailed and exact planning. In craniomaxillofacial surgery advances in imaging techniques (spiral-CT, 3D-imaging) and associated technologies (stereolithographic models, CAD/ CAM) have led to improved preoperative planning. Stereolithography models however do not fulfill the requirements for complex cranio-maxillofacial plastic and reconstructive procedures i.e. preoperative planning with virtual correction, intraoperative navigation and postoperative control. On the base of an axial spiral CT data set computer-assisted planning, intraoperative navigation and postoperative control is performed in cases of complex cranio and maxillofacial reconstruction. We present the use of this technique for preoperative planning including positioning of the distraction devices, navigational control of the osteotomy and postoperative control. Schlagwörter: kraniofazial, Dysgnathie, computer-assistierte Chirurgie

Objectives: Besides the color of the teeth the color of the alveolar gingiva plays a crucial role in esthetic rehabilitation in dento-alveolar treatment. Whereas nowadays the color of the teeth can be determined exactly and individually, the specific influence of the red color of the gingiva on treatment has not been assessed yet. The aim of this study was to evaluate the vascularization as the basis for gingival esthetics. Material and methods: Standardized photographs of defined areas of the alveolar gingiva in operated and non-operated patients were taken and assigned to groups with same characteristics after color comparisons. In addition, histologic and immunohistologic analyses of gingival specimens were performed for qualitative and quantitative assessment of vessels and vascularization. Finally, colors and number of vessels were correlated. Results: Our results demonstrated three different constellations of colors of the alveolar gingiva in healthy patients. The operated patients could not be grouped because of disparate depiction. There was a clear correlation between color and vessel number in the alveolar gingiva. Conclusions: Our investigations revealed the connections between vascularization and gingival color. Recommendations for specific change or even selection of colors based on the results cannot be given, but the importance of vascularly based incision lines was demonstrated . Schlagwörter: gingiva, Vaskularisation, Farbskala, Gefäßdichte, Keratinisierung, oral mucosa, vascularization, color, keratinization

Autologous bone tissue engineering is aimung at the extracorporal rebuilding of lost bone using exclusively cells and matrix from the receiver organism which were manufactured, cultivated and combined in vitro. The aim of this study was to establish a autologous carrier matrix for cells and proteines consisting of fibrin and to characterize the properties of this 100% autologous construction in vitro and in vivo. Eight minipigs were used for manufacturing of the bone substitute using osteoblasts from the calvarian periosteum and endothelial cells from the jugular vein. Cells were cultivated until confluent stage and then seeded on a fibrin matrix based on autologous blood serum, combined with a autologous platelet-rich-plasma-concentrate and replantet in a critical size defect of the mandible. Specimens were taken at day 7 and 14 and analysed. Simultaneous attachment, proliferation, and differentiation of the cells on the carrier matrix was evaluated. In vitro results demonstrated complete attachment of the cells on the matrix surface after 6 hours and distinctive proliferation of both cell types after 48 hours without any apoptotic signs. In 6 of the 8 animals histomorphometric analyses revealed an accelerated bone regeneration. Immunohistologic staining for endothelial cells showed an increased angiogenic front within the fibrin matrix, which was clearly in front of the osteogenic front. With the help of cell tracking technique it was possible to identify the transplanted cells over the whole period of investigation. With this study we could demonstrate the possibility of creating a total autologous bone substitute. Based on vital transplanted cells and the nature of the matrix this construction is able to regenerate a bony defect in a fast and reliable manner. Schlagwörter: Autologes Tissue Engineering, Fibrin, Endothelzellen, Osteoblasten, Autologous tissue engineering, fibrin, endothelial cells, osteoblasts