International Poster Journal of Dentistry and Oral Medicine, 03/2002

A clinical study was carried out on 155 children from Erfurt, Germany, aged in average 30 months to analyse their oral health status (dmft, initial caries lesions, gingivitis, dento-facial anomalies). Salivary tests Dentocult® SM strip mutans were also carried out. For statistical analyses the SAS package with a confidence interval of 95% was used. 83.2% of the subjects were caries free. The caries prevalence was recorded at a value of 0.58 dmft. In 13% of the subjects initial caries was recorded. In more than one third of the children gingivitis was found, with a significantly higher frequency in boys than in girls. The most frequent dento-facial anomaly was the open bite (42%). Whereas in two third of the children no S. mutans was detected in saliva, 24% of children showed even high numbers. A correlation was found between the caries prevalence and the salivary counts of S. mutans. It could be concluded that oral health shows still deficits, expressed by early development of dentinal caries and a relatively high frequency of initial caries lesions. Keywords: early childhood caries, salivary test, s. mutans, oral health status

The immediate loading of dental implants of the partially edentulous patient has not been investigated widely. According to the Ledermann concept immediate loading requires different preconditions like immobilization of the implants by the superstructure and a short surgical and prosthetic treatment (Brunski, 1993). An animal experimental study was performed to evaluate the clinical success and the bone metabolism during the course of osseointegration on 16 implant borne bridges. The premolars and the first molar were removed. After three months the implant placement and prosthetic temporization was performed. The transportation post of the implants was used as a temporary abutment. Prefabricated caps were joint by glass fiber strips for stabilization of the bridge. Templates, which were preformed on cast of the bite before extractions, were used with a methacryl ester material (Protemp Garant, Espe, Germany) to form the bridge. The bridges were cemented at the end of surgery and controlled until the sacrification of the animals. Markers for the histological staining were given according the protocol of Becker et al. (1992).Due to the adaptation of the preparation of the preceptor side according the bone quality with cortical burs in the mandible and with the bone condensing instruments in the maxilla all implants were installed with a minimum insertion torque of 25 Ncm. 85% of the implants showed a higher insertion torque. The procedure with the pre-assembled components and the pre-fabricated auxiliary parts allows fabricating a temporary bridge reconstruction during one appointment. Keywords: immediate loading, posterior mandible, posterior maxilla, internal

A strict surgical protocol requires a stress free healing period of 3 to 6 months for osseointegration. The level of predictability and high success of current implant therapy have provided cause to reevaluate both the surgical and prosthetic protocol. In 1988 P.D. Ledermann described a technique of loading 4 rigidly bar-splinted implants in the edentulous mandible.The presentation 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®, FRIATEC AG 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 results of 25 cases of immediate loading will be presented and discussed. The surgical and prosthetic management of mandibular implant-supported overdenture cases may be greatly simplified with the use of this technique in a carefully selected group of patients. Keywords: immediate loading, anterior mandible, patient satisfaction

The aim of the present investigation was to evaluate several signs and symptoms of TMD as co- factors for tinnitus using data of 3124 subjects of the population based cross-sectional study 'Study of Health in Pomerania' (Ship). The screening was performed with the help of a multivariate logistic regression model which was adjusted for gender, age, and a variety of anamnestic and examined data. The target variable 'tinnitus' was formed from the combination of often- or constantly occurring tinnitus and examination by an ear-nose-throat specialist. As independent variables, the following variables were tested for significance in the logistic regression model: 1. Findings: gender, palpation pain in TMJ or masticatory muscles, pain upon maximal mandibular movement, deviations from straight mouth-opening of > 2 mm, facettes in dental hard tissue and restorations; 2. Anamnestic data: age, (categorized, adjusted according to the first age group), frequent headaches, frequent clenching of the teeth, frequent bruxism, physical complaints of unknown origin, anxiety attacks, worry, unfounded intense fears, agoraphobia, persistent sadness, persistent fatigue and listlessness, persistently overexcited and irritated, existential worry about occupation, high noise levels on the job. Furthermore the impact of signs and symptoms of TMD and tinnitus on the quality of life of this population-based sample was evaluated using the questionnaire SF-12 taken from Bullinger und Kirchberger.Increased Odds Ratios were found for palpation pain of the masticatory muscles (OR=2.3), teeth clenching (2.9), and listlessness (3.1) in females and for frequent headache (6.2) and listlessness (2.1) in males. A relationship between tinnitus and TMD was established only for males. Both disorders may be stress-induced. Keywords: tinnitus, TMD, epidemiology, quality of life

Recently a new ultrasonic system was introduced using a different type of energy transmission in order to offer a less abrasive and less painful therapy. The aim of the present study was to investigate the effects of this system in combination with the straight metal probe compared to conventional ultrasonic and hand instrumentation. 50 extracted decapitated teeth were randomly assigned to 5 groups (n=10). Group 1 was treated with a Gracey curette No. 5 for 3 minutes, group 2 and 3 with the Siroson® S ultrasonic tip for 3 minutes/6 minutes, group 4 and 5 with the Vector®-system for 3 minutes/6 minutes. The Vector®-system was used in accordance with the manufacturer's manual. The samples were fixed in an artificial periodontal socket to simulate a periodontal lesion. Before and after treatment the root surfaces were documented by micrographs. For histological examination the undecalcified samples were cut lengthwise into sections of 20-30 µm thickness. In addition, the treated surface was investigated with SEM using a replica technique. The effects on the root surface were documented by scoring the presence of debris. Descriptive analysis was proved by the Kruskal-Wallis test and Wilcoxon signed rank test. Micrographic analysis showed a most complete calculus removal after hand instrumentation. The conventional ultrasonic system was more effective than the Vector® treatment. SEM evaluation of the hand instrumentation presented a characteristic surface. The conventional ultrasonic system left an irregular surface with smooth areas as well as small defects. The Vector®-system revealed a similar texture as the conventional system. The results were supported by the histological examination. In conclusion the treatment of the root surface with the new ultrasonic device in combination with the straight metal probe resulted in a less effective removal of calculus and more tooth substance preserving procedure. Keywords: ultrasonic instruments, curettes, debridement, root planing, SEM

Objective: The objective of this study was to determine quantitatively the wear resistance of a newly developed light-curing resin for two different types of occlusal splints over a period in situ of six months. Materials and Methods: The study included two samples of ten patients each that had been provided with either stabilization or distraction splints. These occlusal splints were repositioned on remount casts and the occlusal aspect was surveyed prior to insertion and at the four-week, three-month, and six-month recalls. The test setup consisted of an anti-vibration table framework, three translation stages, an inductive displacement transducer, a stereomicroscope, and a digital measurement unit for data acquisition and analysis. The coordinates for the occlusal contacts were stored at the baseline examinations and reproducibly sought out during the recall examinations. Each examination included ten repeat measurements each in the regions of teeth 13, 23, 16, and 26. Results: After six months, the stabilization splints showed a median vertical gain of 1 µm in the region of tooth 13 and a median vertical loss of 24 µm in the region of tooth 23. Regions 16 and 26 exhibited median vertical losses of 37 µm and 33 µm, respectively. In the second sample (distraction splint), the corresponding vertical loss values were 1 µm (tooth 13), 23 µm (tooth 23), 33 µm (tooth 16), and 64 µm (tooth 26). Statistical analysis (Mann-Whitney U-test, p Conclusions: The present study clinically confirms the good wear resistance results of the new resin splint material obtained in a previous in-vitro study [Ottl et al., Dtsch Zahnärztl Z 52, 342 (1997)]. This parameter is of great importance for maintaining the therapeutic mandibular position during the treatment period. Keywords: craniomandibular disorders, temporomandibular joint, clinical follow-up study, occlusal splint therapy, resin, wear resistance

The aim of the study was to analyse complex structured data sets of ECC in 155 children. The children were 30 months old and 45% of their mothers believe that caries is a transmitted disease. For each child an index of caries (dmft) had been recorded together with the number of primary teeth, oral hygiene and gingivitis, salivary mutans streptococci (MS), and drinking behaviour at night with a bottle of soft drinks. Furthermore, a set of structured variables, such as mothers' characteristics (education, occupation) and their effort to control the toothbrushing of the child, was included. The cariogenicity of the food was registered as well. A conditional independence graph was used for analysis of data sets. Studying the graph, it was apparent that MS and dmft formed a separate set with the highest significance (phi 0,346). A negative correlation could be shown between mothers' education and serving of cariogenic food (phi -0,222) and MS counts (phi 0,214). Mothers with high education usually have an occupation (phi 0,21) and check up the toothbrushing of their children (phi -0,107), which have lower MS counts (phi -0,246). Children of mothers with an occupation were put to bed without a nursing bottle of soft drinks (phi -0,172) and had lower plaque indices (phi -0,161). Plaque correlated positive with caries decay, especially with rampant caries (phi 0,231). The results could show that children of mothers with low education have a high risk for ECC. In addition mothers need more information about early transmission of MS. Keywords: caries prevention, early childhood caries, knowledge of mothers, behaviour of mothers, mutans streptococci, transmission

The objective of this study was to visualize and to measure gap formation between dentin and restorative materials. The cusps of 15 extracted human sound molars were cut to expose fresh dentin. The teeth were randomized and divided into 3 groups (n = 5). Cubic cavities (6 x 4 x 4 mm3) were prepared with a diamond bur. The cavosurfaces were etched for 15 s. In order to induce adhesive failures eugenol was applied on one cavity wall, whereas the other cavity walls were left untouched. The cavities were filled with composite (Spectrum), compomer (Dyract AP) or ormocer (Admira) using the recommended bonding agent. All specimens were subjected to a thermomechanical cycling process of 1000 stress cycles (0 / 100N) as well as to 1000 temperature cycles (5° C / 55° C). The teeth were stored in saline at 20° C. Interfaces between cavity walls and restorative materials were inspected after 1 d, 14 d, 63 d and 144 d by confocal laser scanning microscopy (CLSM) in reflection mode. The gap widths (10 per tooth) were documented. In all specimens, measurable gaps could be found only at the eugenol treated surfaces. After 1 d the gap widths were 37.8 ± 4.6 µm for the composite, 30.2 ± 9.9 µm for the compomer and 34.4 ± 9.1 µm for the ormocer. Statistical evaluation (ANOVA) showed a significant (p Keywords: microleakage, composite restoration, base material

The purpose of this single blind cross over study was to compare the cleaning efficacy of a battery powered toothbrush (Dr. Best e-flex 3) and a standard flat trim manual toothbrush (Elmex super 39). In this study 78 healthy subjects took part. Subjects were asked to abstain from all oral hygiene procedures for 48 hours. Af-ter plaque was scored with the Turesky modification of the Quigley Hein Index, the subjects brushed their teeth with either one or the other brush according to a predetermined randomisation schedule: In total, a cleaning time of one minute was given for the whole procedure. Immediately after brushing, plaque was scored again. The same investigator who was blind with respect to the brushes used did all plaque scoring. Subjects were instructed to continue with their usual oral care routine throughout the study period. They were scheduled to return after 12 - 14 days having abstained from all oral hygiene for 48 hours prior to the visit in order to repeat the evaluation sequence but brushing with the alternate brush. The percentage plaque reduc-tion was calculated to compare the cleaning efficacy of the two brushes. Results: Using the non-parametric Wilcoxon test for paired samples (p Keywords: Dr. Best e-Flex 3® battery toothbrush, standard flat trimmed manual tooth brush, plaque removal

Maintaining and reconstructing periimplantary soft tissue are two critical prerequisites for an esthetically successful implant-prosthetic rehabilitation. The goal was to find suitable incision techniques for immediate implant placement that would make it possible to reconstruct various defects in the area of the vestibular alveolar process by means of an appropriate flap design. The primary incision should be made so that it can be extended and so that the need for a later papilla reconstruction can be taken into consideration. Based on our studies and experience, three incisions can be recommended for immediate implant placement. The indicated incisions allow for a flap design that safely covers the necessary augmentative measures. We present a sample case and discuss the results for modifications to the incision and for the papilla reconstruction that may be needed later using micro-scalpels normally used in ophthalmology. From our point of view, suitable incision techniques used in combination with a natural analog implant positioning of implants with expanded diameters will reliably achieve and permanently maintain a natural contour of the gingiva, even in the case of implant reconstruction. Summary - clinical relevance: Depending on the incision during immediate implant placement, one or a few extensive procedures are required for the later shaping of the soft tissue. 1. Exposing the papillas facilitates transgingival healing. 2. Performing the incision with limited mobility makes it possible to create a crestal incision during the opening. 3. Incision with extended mobility often requires surgical papilla reconstruction. Keywords: immediate implantation, implantation and incision line, papilla reconstruction, transgingiva healing, individual abutment, emergence profile, ceramic abutment, bone-collector, soft-tissue management, root analog implant

Recent studies have supported the hypothesis that there is a tendency for evolution in the occlusal relationship of urban populations. In our population , particular interrest is born to incisor guidance and its role in stomatognathic system. Incisal situation and relatioships can be studed with anthropometric and cephalometric determinants This study compares the incisal relationship of two populations of conscripts to the Austrian army, born in 1870 and 1970 respectively. Twenty-four anthropometric and cephalometric points were analysed for 30 subjects from each population. A statistically significant difference between the 1870 / 1970 populations was found for the following criteria (p Keywords: anterior guidance, secular evolution, incisors, orthodontics

Purpose: To test the effect of different base materials on marginal quality of composite restorations after load cycling in vitro. Materials and Methods: Standardized Class I cavities were prepared in 110 extracted human molars. The teeth were randomized and divided into 10 groups (n = 11). Cavities of 8 groups were filled with composite using different base materials or cotton as negative control. Restorations of three more groups were performed with only a composite, a compomer or an ormocer, respectively. All specimens were subjected to a thermomechanical cycling process of 1000 stress cycles (0 / 100N) and 1000 temperature cycles (5° C / 55° C). After dye penetration with rhodamin, the teeth were sectioned and examined by conventional stereomicroscopy (SMi) and by confocal laser scanning microscopy (CLSM). Results: With both methods used, significant differences between the experimental groups were found (Kruskal-Wallis-Test: SMi p=0.02, CLSM p=0.001). Comparing the two microscopical methods it can be stated, that CLSM is more sensitive than SMi. Highest penetration values were detected at the negative control (mean rank: SMi 139, CLSM 161). Under SMi lowest values were found for the all compomer restoration (mean rank: 83) and for one restoration with a glasionomer used as base material (mean rank: 95). With CLSM lowest values were found for one glasionomer/composite (mean rank: 84) and for the all ormocer restorations (mean rank: 93). It is concluded that individual base materials might influence the marginal characteristics of Class I composite restorations. Keywords: microleakage, composite restoration

Transfer of the precise position of implants to a master cast is a prerequisite for an accurate and passive fit of the superstructure. Implants lack the mobility of natural teeth and therefore inaccurate frameworks result in stress within the mechanical parts and the implant-bone interface. Various impression methods have been described to achieve accurate reproduction of the intra-oral relation of the implants. The aim of this experimental study was to compare three different impression materials (polyether, polyvinylsiloxane, hydrocolloid) with the FRIALIT®-2 system and the indirect technique. In addition, the use of transfer caps to improve the transfer precision was tested with all three materials. All measurements were performed using a 3D co-ordinate measuring machine that is capable of locating points in space and calculating the relative distortions as angles of tilt (rot-xy, rot-xz, rot-yz) and 3D displacement. The results suggested that addition silicone and polyether are the materials of choice for implant transfer procedures. The use of transfer caps resulted in a significantly reduced rotation in the xy-plane, but did not improve the absolute 3D displacement. Addition silicone with the use of transfer caps proved to be most precise. The comparison between polyether and polyvinyl siloxane showed significant differences in the xy-rotation and the 3D displacement in favour of the silicone.Since the mean distortion between the original model and the master casts were about 100 µm, absolutely precise fit may be unattainable due to the physical properties of the materials. Further studies will have to evaluate the amount of tolerable stress at the implant-bone interface. Keywords: dental implants, Frialit-2, transfer cap, impression material, impression technique, transfer precision, polyether, polyvinyl siloxane, hydrocolloid, 3D co-ordinate measurement

The aim of the studies was to investigate corrosion processes and surface effects on 6 dental alloys in dependence on organic electrolyte components. For this reason in vitro experiments were carried out in a laboratory bioreactor as follows: 1. Potentiodynamic polarization measurements on dental alloys in different organic electrolytes (microbial culture medium called DNB with and without Streptococcus mutans OMZ 176) under defined test conditions (standard test).2. Potentiodynamic polarization measurments (equal conditions) on precious dental alloys in DNB with and without bacteria in different times after measuring start (0, 6, 12, 24, 48, 72 h) (long-term test).3. Galvanostatic polarization measurement (i=10 µA, t=2h 47min) in an anorganic multicomponent electrolyte according CEN 30993 with and without albumin (1% bovine serum albumin) and determination of the metal release by means of AAS. The results obtained in the organic electrolytes demonstrate that the current density-potential-curves are moved to higher potentials in comparison to measuring in inorganic electrolytes. The long-term tests show also a moving of the curves to higher potentials after a time of 72 hours. The current density decreases in the same time. This phenomen is caused by formation of biofilms.Further an addition of albumin causes an increase of galvanostatic pitting potential, what refers to a formation of biofilms. This is opposed to the amount of released ions determined in the electrolyte with albumin. The corrosion behaviour is mainly influenced by the quality of the electrolyte, especially of organic components. Therefore in vitro-corrosion tests of metallic biomaterials should be carried out under simulated biological conditions. Keywords: dental alloy, corrosion, biocompatibility, organic electrolytes, ion release

Recently a new method of surface finishing has been introduced in dental technology: It is a micro-dry blasting method, which works with two different blasting media. The first one is to reduce surface near layer, containing microstructural defects, the other one results in a surface strengthening by shot peening. The aim of the study was to verify the improving effect of this blasting technique on dental alloys and to investigate the corrosion behaviour of dental alloys after using micro-blasting. For this reason a high gold- and cobalt-base alloy and Titanium were tested as follows:Samples of the materials were treated by Micro-Finishing with an abrasive and spherical blasting medium separate and in combination. The finished surfaces were characterised by light-and scanning-electron-microscopy (SEM) and analysed profile graphically (RZ). The microhardness (MHV 0,02) was tested on transverse sections in distances of 10, 20, 100 µm and in the middle of the sample. Additionally electro-chemical tests were made in a 0,9% sodium chloride solution (pH=7,4). The resting potentials were recorded and the breakdown potentials evaluated. Using the micro-blasting technique enables an improvement of the surface structure by smoothing and strengthening the surface and increasing their microhardness. The corrosion behaviour shows a higher passivation. Keywords: surface finishing, shoot peening, dental alloy, precious dental alloys, non precious dental alloys, titanium, metallographic structure, corrosion behaviour, profile graphic analyses

0bjectives:ln recent years implant surfaces intensively have been optimized. So far standards for surface characterisation by the various methods of determining morphometric and topographic parameters are discussed in controversy. Confocal laser scanning microscopy (CLSM) in 3D-TOPO mode is the alternative presented here. Method: With this technique 35 commercially available dental implants were inspected (each at 5 different locations). The roughness value Sa and the developed surface area (ratio) Sdr were derived from the obtained 3D images. Implants were grouped according to the type of surface treatment. Results Machined (n=2) Ablative (n=17) Ti coating (n=9) HA coating (n=7) Sa [µm] 0.5 [0.3-0.7] 3.1 [1.7-4.9] 6.0 [3.4-9.8] 5.8 [4.8-7.1] Sdr [%] 3.1 [2.4-3.7] 11.4 [5.4-19.6] 14.3 [9.4-19.7] 18.4 [13.1-31.4] Keywords: dental implants, surface, CLSM