Equivalence study of the resin-dentine interface of internal tunnel restorations when using an enamel infiltrant resin with ethanol-wet dentine bonding.

This preregistered ex vivo investigation examined the dentinal hybrid layer formation of a resinous infiltrant (Icon), with reference to both thickness (HLT) and homogeneity when combined with modified tunnel preparation (occlusal cavity only) and internal/external caries infiltration. The adhesives Syntac and Scotchbond MP were used as controls (Groups 1 and 3) or in combination with Icon (Groups 2 and 4). A split-tooth design using healthy third molars from 20 donors resulted in 20 prepared dentine cavities per experimental group. The cavity surfaces (n = 80) were etched (37% H3PO4), rinsed, and air-dried. Rewetting with ethanol was followed by application of the respective primers. After labeling with fluorescent dyes, either Syntac Adhesive/Heliobond or Scotchbond MP Adhesive was used alone or supplemented with Icon. HLT, as evaluated by scanning electron microscopy, did not significantly differ (P > 0.05), and confocal laser scanning microscopy revealed homogeneously mixed/polymerized resin-dentine interdiffusion zones in all groups. Icon can be successfully integrated into an ethanol-wet dentine bonding strategy, and will result in compact and homogeneous hybrid layers of comparable thickness considered equivalent to the non-Icon controls, thus allowing for preservation of the tooth's marginal ridge and interdental space in the case of internal/external infiltration of proximal caries.

Effects of CBCT acquisition protocol and additional superimposed computerized optical impressions on the accuracy of root canal length measurements: an ex vivo study.

AIM: The purpose of the present investigation was to evaluate the accuracy of root canal length (RCL) determination according to CBCT acquisition protocol and evaluate the influence of additional superimposed computerized optical impressions. MATERIALS AND METHODS: CBCT scans with low-dose (LD) and high-definition (HD) protocols as well as computerized optical impressions of 30 extracted human molars were acquired. Sicat Endo software (Sicat) was used for CBCT RCL measurements with (LD+, HD+) and without (LD-, HD-) a superimposed optical impression. To evaluate the accuracy, absolute differences between test groups and the actual root canal length (ARCL) were calculated and statistically analyzed using the Wilcoxon rank sum test. RESULTS: Absolute differences between the ARCL and the tested measurement methods varied significantly (P < 0.05). Both higher resolution and additionally superimposed computerized optical impression improved measurement accuracy. Mean differences compared with the ARCL were 0.26 mm (HD+), 0.34 mm (HD-), 0.43 mm (LD+), and 0.66 mm (LD-). 93.4% of all measurements in the HD+ group were within the limits of ± 0.5 mm. CONCLUSION: Both resolution and superimposition of additional computerized optical impressions have a significant influence on RCL measurements using CBCT.

Influence of Connector Diameter on Fracture Load of CAD/CAM-Processed Monolithic Lithium Disilicate Fixed Partial Dentures.

PURPOSE: To investigate the influence of connector diameter on the mechanical load to fracture in monolithic three-unit lithium disilicate fixed partial dentures (FPDs). MATERIALS AND METHODS: A total of 24 FPDs were designed and manufactured using computer-aided design/computer-assisted manufacturing (CAD/CAM) with connector diameters of 16 mm2, 12 mm2, or 9 mm2 (Groups A, B, and C, respectively; n = 8 for each group). After thermal and mechanical aging, the FPDs were subjected to mechanical load-to-fracture assessment. RESULTS: Fracture loads of Groups B (834 ± 105 N) and C (796 ± 41 N) were significantly lower compared to Group A (990 ± 65 N). CONCLUSION: Connector dimensions proved to be crucial for fracture resistance of monolithic lithium disilicate FPDs.

Development of an analytical prepCheck-supported approach to evaluate tutor-based assessments of dental students' practical skills.

The aim of the present study was to develop an analytical computer-supported assessment concept for the objective evaluation of students' practical skills, and to investigate the assessor-dependent differences by setting tolerance limits applied during the 'glance and grade' evaluation. A sample of 54 conventionally supervised dental undergraduates were given training in the preparation of a macroretentive Class II cavity. The course participants then took a mandatory practical examination. Three (plus one) course instructors performed the visual evaluations of the examination tasks according to predefined assessment criteria, followed by optical impressions (quadrant scan using Omnicam; Cerec; Dentsply Sirona, Wals, Austria) and subsequent assessment of the prepared cavities (tooth 46) using the prepCheck application (Dentsply Sirona). In this course, the maximum permissible deviation was set at ± 10% from the predefined assessment criteria. If no tolerance was applied, the statistical analysis revealed a significant difference between the actually achieved cavity dimensions and the predefined values of a master preparation (P = 0.0001; Student's t-test), thus leading to an overall failure rate of 100%. The application of the initially targeted 10% tolerance led to an insignificant reduction (96.3%), while the stepwise elevation of the permissible deviation up to 35% finally matched with the result of the visual assessment (total failure rate of approximately 20%). Unlike the pronounced subjectivity of the tutors during the assessment of students' practical skills, the utilization of the prepCheck application enables precise evaluations. Further studies are clearly warranted to investigate the possible educational outcome of an advanced interactive computer-supported training with implemented tolerance corridors.

Ex vivo investigation on the postoperative integrity of the apical constriction after the sole use of electronic working length determination.

AIM: The present study investigated the accuracy of root canal preparation with regard to the integrity of the apical constriction (AC) using two different working length determination approaches: (1) the electronic method of working length determination (EWLD), and (2) the radiologic "gold standard" method (GS). METHODOLOGY: Simulation models were constructed by arranging extracted human teeth by means of silicon bolstered gingiva masks, along with a conductive medium (alginate). Electronic working length determination (group 1; EWLD) and radiologic plus initial electronic working length determination for posterior comparability (group 2; GS) preceded manual root canal preparation of teeth in both groups. Master cones were inserted according to working lengths obtained from the group specific method. Subsequently, root apices (n=36) were longitudinally sectioned using a diamond-coated bur. The distance between the achieved apical endpoint of the endodontic preparation and the apical constriction (AC) was measured using digital photography. Then, distances between radiologically identified apical endpoints and AC (GS-AC) were compared with the corresponding distances EWLD-AC. Moreover, the postoperative status of the AC was examined with regard to both preparation approaches. RESULTS: Differences between distances GS-AC and EWLD-AC were not statistically significant (p >0.401) (Mann-Whitney-U). Among EWLD samples, 83% of the master cones exhibiting tugback at final insertion terminated close to the apical constriction (±0.5 mm), and no impairment of the minor diameter's integrity was observed. CONCLUSIONS: The sole use of EWLD allowed for a high accuracy of measurements and granted precise preparation of the apical regions.

Resin infiltration of deproteinised natural occlusal subsurface lesions improves initial quality of fissure sealing.

The aim of this ex vivo study was to evaluate the infiltration capability and rate of microleakage of a low-viscous resin infiltrant combined with a flowable composite resin (RI/CR) when used with deproteinised and etched occlusal subsurface lesions (International Caries Detection and Assessment System code 2). This combined treatment procedure was compared with the exclusive use of flowable composite resin (CR) for fissure sealing. Twenty premolars and 20 molars revealing non-cavitated occlusal carious lesions were randomly divided into two groups and were meticulously cleaned and deproteinised using NaOCl (2%). After etching with HCl (15%), 10 premolar and 10 molar lesions were infiltrated (Icon/DMG; rhodamine B isothiocyanate (RITC)-labelled) followed by fissure sealing (G-ænial Flo/GC; experimental group, RI/CR). In the control group (CR), the carious fissures were only sealed. Specimens were cut perpendicular to the occlusal surface and through the area of the highest demineralisation (DIAGNOdent pen, KaVo). Using confocal laser-scanning microscopy, the specimens were assessed with regard to the percentage of caries infiltration, marginal adaption and internal integrity. Within the CR group, the carious lesions were not infiltrated. Both premolar (57.9%±23.1%) and molar lesions (35.3%±22.1%) of the RI/CR group were uniformly infiltrated to a substantial extent, albeit with significant differences (P=0.034). Moreover, microleakage (n=1) and the occurrence of voids (n=2) were reduced in the RI/CR group compared with the CR group (5 and 17 specimens, respectively). The RI/CR approach increases the initial quality of fissure sealing and is recommended for the clinical control of occlusal caries.

Radiologic assessment of quality of root canal fillings and periapical status in an Austrian subpopulation - An observational study.

BACKGROUND/OBJECTIVE: Progress in endodontic techniques and methodological advances have altered root canal therapy over the last decades. These techniques and methods need periodical documentation. This observational study determined the current prevalence of endodontic treatments, and investigated the relationship of various factors with the periapical status in a Lower Austrian subpopulation. METHODOLOGY: One thousand orthopantomograms of first-time university adult patients radiographed at an outpatient clinic were evaluated. For each tooth, the presence of periradicular pathosis and/or endodontic treatment was recorded, as was the quality of (post-)endodontic treatment (homogeneity and length of root canal fillings; preparation failures; posts/screws; apicoectomies; coronal restorations). Two evaluators, blinded to each other, scored all teeth. In cases of disagreement, they joined for a consensus score. RESULTS: In all, 22,586 teeth were counted. Of these, 2,907 teeth (12.9%) had periapical pathosis, while 2,504 teeth had undergone root canal treatment. Of the endodontically treated teeth, 52% showed no radiographic signs of apical periodontitis, while 44.9% had overt apical lesions, and 3,1% revealed widened periodontal ligament space. The majority of the root canal fillings was inhomogeneous (70.4%); 75.4% were rated too short, and 3.8% too long. The presence of apical pathosis was significantly correlated (odds ratio (OR) 2.556 [confidence interval (CI) 2.076-3.146]; P<0.0001) with poor root canal fillings (length and homogeneity). Posts or screws positively affected periapical status (OR 1.853 [CI 1.219-2.819]; P = 0.004), but endodontically treated posterior teeth were infrequently restored (posts, 7.5%; screws, 2.7%). Best results were found for teeth with both appropriate endodontic treatment and adequate coronal restoration. CONCLUSION: A high prevalence of periradicular radiolucencies was observed with root canal filled teeth, along with high numbers of unmet treatment needs. Periapical health was associated with adequate root canal obturation and high-grade postendodontic restorations, and quality regarding these latter aspects is considered mandatory to promote periapical health.

External and internal resin infiltration of natural proximal subsurface caries lesions: A valuable enhancement of the internal tunnel restoration.

OBJECTIVE: The aim of this ex-vivo study was to evaluate both the external and the internal penetration ability of a resin infiltrant into natural proximal and macroscopically intact white spot lesions, and to merge this approach with the internal tunnel preparation concept. METHOD AND MATERIALS: 20 premolars and 20 molars with proximal subsurface lesions (ICDAS, code 2) and respective radiographic lesion depths extending into the middle third of dentin (D2 lesions) were selected and divided into two groups. Treatment needs were confirmed using digital imaging fiber-optic transillumination and laser fluorescence. Deproteinization (NaOCl; 2%) followed, and lesions of Group 1 (control; n = 20) were etched (HCl; 15%) and externally infiltrated (Icon). Accordingly, the specimens of Group 2 (n = 20) were treated with the resin infiltrant from external; then, internal Class I tunnels were prepared, lesions were internally infiltrated (Icon), and the occlusal cavities were restored (G-ænial Flo X) after etching (H3PO4 gel; 40%). Teeth were cut perpendicular to the proximal lesion surfaces, and percentage infiltrations were analyzed using confocal laser microscopy and a dedicated image manipulation program (GIMP). RESULTS: Regarding the external infiltration, no differences between both groups were detected (P = .114; Mann-Whitney). Additional internal application of the resin infiltrant significantly increased the percentage amount of enamel lesion infiltration (P < .0001; Wilcoxon). CONCLUSION: External and internal infiltration seem to complement the internal tunnel approach, thus remediating the drawbacks of the latter by occluding and stabilizing the porous areas of the proximal caries lesion, and preserving both the marginal ridge and the proximal contact area.

Development and Evaluation of an Endodontic Simulation Model for Dental Students.

The aims of this study were to develop an endodontic simulation model able to implement the electronic method of working length determination (electronic apex locators, EALs) in a dental school, to evaluate the practicality of this tool for dental students, and to compare the accuracy of working length measurements achieved by the EAL and the radiographic method. A new simulation model was constructed by embedding extracted human teeth in a self-cured resin, along with a conductive medium. After radiographic and electronic working length determinations, root canal instrumentation was performed by students at a dental school in Austria according to the working lengths obtained from the EAL. Subsequently, root apices (n=44) were longitudinally sectioned using a diamond coated bur. Measurements of the distance between the anatomical root apex (ARA) and the apical constriction (AC) as well as between ARA and the ascertained apical point of endodontic instrumentation were performed using digital photography and a 3D computer-assisted design software. The distance between ARA and the radiologic (ARA-R) or electrometric (ARA-EL) readings of the apical point of endodontic instrumentation was compared with the actual distance ARA-AC. The accuracy of both methods was determined. The difference between the actual distance ARA-AC and the targeted radiological distance was statistically significant (p=0.0001), as was the measured distance between ARA-R and ARA-EL (p=0.016). The electronic method seems to be more precisely referring to the AC (R(2)=0.0198) than the radiographic method (R(2)=0.0019). These results suggest that the endodontic simulation model described in this study can be successfully used in preclinical dental education.

Tridimensional surface roughness analysis after resin infiltration of (deproteinized) natural subsurface carious lesions.

OBJECTIVES: The objectives of this study were to evaluate ex vivo the effects of resin infiltration on the areal surface roughness of natural non-cavitated proximal subsurface lesions with or without previous deproteinization and to determine differences between E2 and D1 lesions or between premolars and molars. MATERIALS AND METHODS: Forty premolars and 40 molars with proximal carious lesions and macroscopically intact surfaces (International Caries Detection and Assessment System (ICDAS) II; code 2) were radiologically assessed and randomly allocated to four groups (with 20 E2 and 20 D1 lesions, respectively). In each group, 10 lesions were deproteinized (NaOCl; 1%) before etching (HCl; 15%) and resin infiltration (Icon). Areal surface roughness (Sa) at the most demineralized lesion part (DIAGNOdent) was evaluated topometrically before and after deproteinization, after etching, and after infiltration using focus variation 3D scanning microscopy. RESULTS: Pretreatment with NaOCl (n = 40) had no significant effects on Sa (p = 0.208), but resulted in significantly differing Sa values between premolars and molars after etching (p = 0.011). Regarding the effects between etching and baseline, significantly differing Sa values (p = 0.0498) were found for premolars and molars (n = 40/40); Sa after resin infiltration (compared to etching) differed significantly between premolars and molars (p = 0.009). No treatment regimen lead to differences among the radiological grades (E2 vs. D1; p > 0.106). CONCLUSIONS: Resin infiltration showed only minor effects on Sa values of etched subsurface lesions (p < 0.170) and did neither equal nor improve baseline surface roughness (p > 0.401) of the different tooth types. CLINICAL RELEVANCE: Deproteinization should be recommended before etching and infiltration, even if surface roughness of infiltrated advanced (pre-)molar lesions will not be improved.

Controlled modulation of serum protein binding and biodistribution of asymmetric cyanine dyes by variation of the number of sulfonate groups.

To assess the suitability of asymmetric cyanine dyes for in vivo fluoro-optical molecular imaging, a comprehensive study on the influence of the number of negatively charged sulfonate groups governing the hydrophilicity of the DY-67x family of asymmetric cyanines was performed. Special attention was devoted to the plasma protein binding capacity and related pharmacokinetic properties. Four members of the DY-67x cyanine family composed of the same main chromophore, but substituted with a sequentially increasing number of sulfonate groups (n  =  1-4; DY-675, DY-676, DY-677, DY-678, respectively), were incubated with plasma proteins dissolved in phosphate-buffered saline. Protein binding was assessed by absorption spectroscopy, gel electrophoresis, ultrafiltration, and dialysis. Distribution of dye in organs was studied by intraveneous injection of 62 nmol dye/kg body weight into mice (n  =  12; up to 180 minutes postinjection) using whole-body near-infrared fluorescence imaging. Spectroscopic studies, gel electrophoresis, and dialysis demonstrated reduced protein binding with increasing number of sulfonate groups. The bovine serum albumin binding constant of the most hydrophobic dye, DY-675, is 18 times higher than that of the most hydrophilic fluorophore, DY-678. In vivo biodistribution analysis underlined a considerable influence of dye hydrophilicity on biodistribution and excretion pathways, with the more hydrophobic dyes, DY-675 and DY-676, accumulating in the liver, followed by strong fluorescence signals in bile and gut owing to accumulation in feces and comparatively hydrophilic DY-678-COOH accumulating in the bladder. Our results demonstrate the possibility of selectively controlling dye-protein interactions and, thus, biodistribution and excretion pathways via proper choice of the fluorophore's substitution pattern. This underlines the importance of structure-property relationships for fluorescent labels. Moreover, our data could provide the basis for the rationalization of future contrast agent developments.

Optical imaging of CCK2/gastrin receptor-positive tumors with a minigastrin near-infrared probe.

PURPOSE: A variety of tumors in different organs with good accessibility to near-infrared light express the cholecystokinin-2 (CCK2)/gastrin receptor. Therefore, the applicability of fluorescence optical imaging was assessed using a novel peptide probe. MATERIALS AND METHODS: This study was approved by the regional animal committee. Our optical peptide probe (DY-minigastrin) was synthesized by coupling a hemicyanine dye to a gastrin derivative peptide (minigastrin). In vitro CCK2/gastrin receptor identification was performed in receptor-positive HT-29 and negative A-375 cells using flow cytometry, laser scanning microscopy, and macroscopic near-infrared fluorescent (NIRF) imaging. For in vivo studies, tumor cells were implanted into mice, and DY-minigastrin in presence or absence of nonlabeled minigastrin (control of signaling specificity) was applied intravenously. Fluorescence signals in tumors and organs were recorded and statistically analyzed. RESULTS: Flow cytometry, laser scanning microscopy, and in vitro macroscopic imaging of cell pellets revealed a distinct accumulation of our minigastrin probe in HT-29 cells, showing distinct probe internalization. In vivo NIRF whole-body animal imaging, again, demonstrated a clear depiction of HT-29 tumors, which was reversed by blocking with nonlabeled minigastrin. Semi-quantitative fluorescence analysis and histologic observations were in agreement with these observations. A distinct probe organ distribution was observed. CONCLUSIONS: Our observations indicate that DY-minigastrin-based NIRF optical imaging of CCK2/gastrin receptor protein is feasible. Because of its widespread occurrence in different tumor types, endoscopic, laparoscopic, and tomographic receptor imaging could be accomplished in the near future.

Survey of electromagnetic field exposure in bedrooms of residences in lower Austria.

Previous investigations of exposure to electric, magnetic, or electromagnetic fields (EMF) in households were either about electricity supply EMFs or radio frequency EMFs (RF-EMFs). We report results from spot measurements at the bedside that comprise electrostatic fields, extremely low-frequency electric fields (ELF-EFs), extremely low-frequency magnetic fields (ELF-MFs), and RF-EMFs. Measurements were taken in 226 households throughout Lower Austria. In addition, effects of simple reduction measures (e.g., removal of clock radios or increasing their distance from the bed, turning off Digital Enhanced Cordless Telecommunication (DECT) telephone base stations) were assessed. All measurements were well below International Commission on Non-Ionizing Radiation Protection (ICNIRP) guideline levels. Average night-time ELF-MFs (long-term measurement from 10 pm to 6 am, geometric mean over households) above 100 nT were obtained in 2.3%, and RF-EMFs above 1000 microW/m(2) in 7.1% of households. Highest ELF-EFs were primarily due to lamps beside the bed (max = 166 V/m), and highest ELF-MFs because of transformers of devices (max = 1030 nT) or high current of power lines (max = 380 nT). The highest values of RF-EMFs were caused by DECT telephone base stations (max = 28979 microW/m(2)) and mobile phone base stations (max = 4872 microW/m(2)). Simple reduction measures resulted in an average decrease of 23 nT for ELF-MFs, 23 V/m for ELF-EFs, and 246 microW/m(2) for RF-EMFs. A small but statistically significant correlation between ELF-MF exposure and overall RF-EMF levels of R = 0.16 (P = 0.008) was computed that was independent of type (flat, single family) and location (urban, rural) of houses.

Fluorescent liposomes as contrast agents for in vivo optical imaging of edemas in mice.

This study assesses if specially designed fluorescent liposomes can be used as contrast agent for near-infrared fluorescence (NIRF) optical imaging of cultured macrophages in vitro and for NIRF imaging of inflammatory processes, like edema, in an in vivo mouse model. Fluorescent liposomes are prepared by the film hydration and extrusion method using cholesterol, L-phosphatidylcholine, and the NIR fluorescent dye DY-676-C(18) ester. Photon correlation spectroscopy and flow cytometry reveal that fluorescent liposomes are structurally stable for up to 133 days. Distinct uptake/labeling of cultured murine J774 macrophages is demonstrated by confocal laser scanning microscopy (CLSM), flow cytometry, and macroscopic NIRF imaging system at wavelengths >670 nm. Moreover, CLSM analysis reveals fluorescence signals within intracellular compartments. Ear edema is induced in mice (n = 16) by subcutaneous injection of zymosan A. Whole-body NIRF imaging is performed after intravenous injection (0-24 h) of fluorescent liposomes (55 nmol dye per kg body weight). Distinctly higher fluorescence intensities (1613.6 +/- 61.7 a.u.) are detected at inflamed areas of diseased mice as compared to controls (892.8 +/- 19.4 a.u.). Furthermore, cell isolated from ear lavage reveals the presence of labeled F4/80 positive tissue macrophages. Taken together, the results indicate both that mouse macrophages labeled with fluorescent liposomes can be detected in vitro with fluoro-optical methods and that in vivo optical imaging of inflammatory processes with fluorescent liposomes as contrast agent is feasible. Possibly, early stages of other inflammatory diseases could also be detected by the proposed diagnostic tool in the long term.

Oral health with fixed appliances orthodontics.

Orthodontic treatment represents an important fraction in dental interventions. According to other medical methods the question for scientific evidence for the effectiveness of these treatments arises. The question of the effectiveness is connected with the question what is understood as an effect. In principle, the effect of the intervention is understood on the basis of the occlusion or dental health, what disregards further functions of oral health. The generalization to oral health is therefore a necessary consideration in science now. If one appreciates this further development, then there is no one single randomised study available which examines the long-term effect of the orthodontic intervention or for the effects on the oral health.The question, whether the application of a fixed appliance in an orthodontic treatment causes a long-term improvement in oral health, cannot be answered at the present time. The scientific status is the definition of oral health at present. Also the question, whether in the long run the dental health can be improved by fixed appliances cannot be answered with a quality usually achieved by evidence-based medicine. Whether correction of a dental malposition is an effective prerequisite for the preservation of the natural teeth, cannot be answered. There is no generalizing study with sufficient scientific background for Europe or Germany to this topic. The risk for caries cannot be quantified. Caries is identified as a central topic in general but due to numerous factors influencing the risk it is not quantified. The question of the indications is completely open from the scientific literature. For the question of the therapy need or therapy priority some indexes were developed, which lead to a quantification. These indices however are fundamentally criticised by recent research in their meaning and the empirical relevance.There is an impression that there exists a big gap between the practical application and the scientific investigation of this effectiveness of fixed appliances or orthodontic treatment in general. There is much research in the area of diagnostics or further development of appliances or techniques done, however extremely few in the area of need for intervention, analysis of the sustainability; influence factors on the success, like caries or quantification of side effects e. g. root resorption. This research to evaluate the indications is completely lacking, also the required evaluation parameters (e. g. means long-term dental maintenance). This gap is in this respect dubious since a link of determining the demand (inducing demand) and supply in Central European health systems is economically given. This enables to create a possibility for a so-called supply induced demand. To get rid of discussions that the professional work of orthodontics can be near to induced demand or unnecessary indications, research of this topic is quite essential. This requires much stronger information for indications. This can improve confidence for patients and insurance companies. Existing indices like the Index of Treatment Need (IOTN) seem to be of academic interest without practice importance for daily work. The question which indications can be regarded as scientifically proven for the intervention must be given big attention immediately. The individual and subjective assessment of the orthodontist (whose experience is not doubted) has to be considered as not sufficient. The scientific background is absolutely necessary due to ethic reasons for the patient, economic reasons for the social insurance system or financiers and also for the orthodontists to evaluative and legitimates the treatment. Well coordinated research with the goal of collecting specific data is urgently required for individual therapeutic processes with appropriate design. The study quality is also an essential topic. It is unacceptable at the beginning of the 21st century with the background of the evidence based medicine, that studies are published with enormous methodological errors. Orthodontics deserves a well discussed scientific position to prove the enormous individual success and to demonstrate the effectiveness of the developed treatments.

The treatment of Parkinson's disease with dopamine agonists.

Parkinson's disease is a chronic degenerative organic disease with unknown causes. A disappearance of cells with melanin in the substantia nigra is considered as biological artefact of the disease, which causes a degenerative loss of neurons in the corpus striatum of mesencephalon. This structure produces also the transmitter substance dopamine. Due to this disappearance of cells dopamine is not produced in a sufficient quantity which is needed for movement of the body.The questions of this report are concerned the efficiency and safety of a treatment with dopamine agonists. Furthermore the cost-effectiveness is investigated as well as ethic questions. The goal is to give recommendation for the use of dopamine agonists to the German health system.A systematic literature search was done. The identified studies have different methodological quality and investigate different hypothesis and different outcome criteria. Therefore a qualitative method of information synthesis was chosen.Since the introduction of L-Dopa in the 1960´s it is considered as the most effective substance to reduce all the cardinal symptoms of Parkinson disease. This substance was improved in the course of time. Firstly some additional substances were given (decarbonxylase inhibitors, catechol-o-transferase inhibitors (COMT-inhibitors), monoaminoxydase-inhibitors (MAO-inhibitors) and NMDA-antagonists (N-Methyl-d-aspartat-antagonists).In the practical therapy of Parkinson dopamine agonists play an important role, because they directly use the dopamine receptors. The monotherapy of Parkinson disease is basically possible and is used in early stages of the disease. Clinical practise has shown, that an add on therapy with dopamine agonists can led to a reduction of the dose of L-dopa and a reduction of following dyskinesia.The studies for effectiveness include studies for the initial therapy, monotherapy and add-on-therapy. Basically there is a good effectiveness of dopamine agonists the reduce dyskinesia and this differences are statistically significant. The effect of dopamine agonists is weaker then levodopa generally. The initial therapy with dopamine agonists can postpone the use of levodopa medication or keep the dose small for a longer period of time. There are more other side effects to levodopa, these are not statistically significant. The idea, which strategy for the treatment should be chosen is dependent of several factors and has to be evaluated with the individual patient. An important criterion is the age of the patient at the beginning of the treatment. For younger patients (under 65 years) the risk of developing motoric fluctuation and dyskinesia is much higher and therefore it is proposed to use levodopa at later stages. The evidence of the evaluated studies show a good effectiveness with the therapy of Parkinson disease as monotherapy of younger patients or as additional medication to levodopa as well as older patients with progressive stages of this disease. In these groups of patients there is a positive cost-benefit ratio.

Value of intensified nursing.

The concept "intensified nursing" is mentioned in differentiation to concepts of "nursing care" or "nursing" which intensifies resources or patient contact. Especially psychic and social needs of patients are very appreciated in nursing. A similar type of nursing is known under the concept "advanced nursing practice" (ANP) which means, that a specialised, academically trained nurse offers an extended nursing care in which a focus on the published knowledge of evidence based research is made.From the thin literature to this topic a selection of predetermined topics was analysed where at least two articles with a sufficient high methodical quality were available. The selected topic groups were: "Infant and paediatric nursing", "gerontology" and "oncology". Generally the five publications concerning infant and paediatric nursing could conclusive show a benefit of intensified nursing. Further research is still needed to prove intensified nursing care. Two publications could be found to the gerontological intensified nursing; both used an extended nursing model and an enlarged use of resources. Both studies demonstrated a measurable success in the applied parameters. Two studies also could be analysed in the oncological field in which successes were also provable by the applied parameters. The success was given especially in a higher patient satisfaction, one study showed an improved scheduling (time planning) of nurses.There was not one article concerning economic questions of intensified nursing care. It has to be taken into account that the financial resources have to be used effectively also in nursing nowadays. It has to be assumed that the costs are driven by increased use of resources. Savings can be achieved, however, in the form of avoided therapies and days in hospital by intensified nursing. The intensified nursing can be considered as similar cost-effective as conventional models of nursing.Ethically it is necessary to consider that the possibilities of the intensified nursing should be exhausted as much as possible for the patients. The daily work is limited, due to restrictions of resource. This means a conflict for nurses between knowledge and the predefined resource requirements which often leaded to overtaxing and dissatisfaction. It is desirable that decision makers of the health policy appreciate the evidence and promote intensified nursing care models.Nursing science has to do special research to prove the meaning and effectiveness of intensified nursing and establish this in the health care delivery system.

Bypass operation at the beating heart in comparison to the operation with support of the heart-lung machine.

The coronary Bypass operation at the beating heart ("off-pump surgery") is a new procedure which promises advantages in comparison to the established procedure with uses a heart-lung machine ("on-pump-surgery"). In the presented HTA report cardiac surgery the question is investigated, whether there are advantages of the off-pump-surgery in comparison to the on-pump-surgery regarding medical effectiveness, safety as well as cost effectiveness. At the beginning a systematic literature search was done, the articles were classified according to the hierarchy of evidence. There are partly considerable different groups of patients included in the different studies as well as quite different outcome parameters. The quality of the studies in detail, where at least two groups are compared was generally very good.The studies results show more or less equivalent results in the comparison of the two operation techniques. Concluding neither a clinical superiority nor an inferiority on the basis of the present available studies can therefore be proven (off-pump Coronary Artery Bypass; OPCAB) or the conventional bypass operation with use of the heart-lung machine (Coronary Artery Bypass Graft; CABG can).The diagnostic criteria of a patient who is allocated to the one or other operating technique are important. Due to technical reasons the majority of patients with the necessity of a bypass operation con only be treated by CABG, (on-pump-surgery). These criteria for the allocation of operation techniques should be the important components of optimization considerations.

Therapy of unspecific tinnitus without organic cause.

INTRODUCTION: There is a variety of medical and non-medical therapies in practice, which were not evaluated regarding its effectiveness by any systematic evidence oriented investigation. A number of therapies of medical and non-medical type try to treat the different types of tinnitus. The evidence in the scientific literature also had to be cleared in the field of diagnosis and classification as well as medical/psychiatric/psychological procedures of existing medical therapy. QUESTION: The HTA report had to investigate the following questions: Which evidence do diagnostic methods in recognition of tinnitus have? Which types of therapy show medical effectiveness at the acute or chronic tinnitus without an organic cause? Which consequences (need for further research, future procedures) can be drawn? METHODOLOGY: In the following databases "tinnitus" was searched according to the search string: HTA97; INAHTA; CDAR94; CDSR93; CCTR93; ME66; ME0A; HT83; SM78; CA66; CB85; BA70; BA93; EM74; IS74; ET80; EB94; IA70; AZ72; CV72; GE79; EU93; HN69; ED93; EA08 RESULT: 1932 studies, unsorted after assessment in accordance with EBM criterions, selection: 409 studies. Due to the completely heterogeneous representation modes of the therapeutic approaches at the treatment of the chronic tinnitus no quantitative synthesis method could be performed. Therefore the methodology of a qualitative overview has been carried out. RESULTS: The diagnostic confirmation of the non-specific tinnitus without organic cause meets with the problem of the assurance of the diagnosis tinnitus. According to the current opinion the stepwise diagnostics is carried out also in the case of the so called subjective tinnitus. Nothing can be said about the evidence of these procedures since no publication was found about that. A study concerning the evidence of the diagnostic questionnaires from Goebel and Hiller [1] comes to the end that the tinnitus questionnaire frequently used (TF) [2] is the best evaluated procedure. The number of therapies which treat tinnitus is exceptionally high and makes clear, that the search for "the" tinnitus therapy is still going on. According to the current knowledge tinnitus genesis is multifactorial and therefore there can't be any standard therapy for tinnitus. The following seven categories can be distinguished: AD 1: MACHINE-AIDED ACOUSTIC THERAPIES From many studies regarding machine-aided acoustic therapy of tinnitus only two showed an evidence degree that allows scientifically correct statements about the effectiveness of these procedures. Selectively significant improvements could be shown in the comparison with a placebo (apparatus switched off) a superiority of tinnitus-maskers. AD 2: ELECTROSTIMULATION In an application study of electro-stimulation the results were not evaluated statistically, but it was described descriptively that a successful medical treatment can be expected in about 50% of the cases. AD 3: PSYCHOLOGICAL THERAPY PROCEDURES Hypnosis did not show positive effectiveness. With regard to biofeedback it can be concluded that this method can be effective in individual cases, however regarded as unreliable from missing reproducibility. Neurobiofeedback could prove that it had a positive therapeutic effect. From eight controlled studies to relaxation techniques and cognitive behaviour therapy four studies showed a therapeutic effectiveness and four failed. Combined therapies proved generally to be more effective than individual types. The behaviour medical psychotherapy could show a positive therapy effect. In a study with cognitive therapy and relaxation (three groups, a passive relaxation, an active relaxation and a cognitive therapy) short-term successes could be stated (for one month), however, the parameters of success returned on the initial value after four months. Also only coincidental and short-term successes could be achieved with cognitive behaviour therapy training, autogenic training and structured group psychotherapy. AD 4: TINNITUS RETRAINING THERAPY (TRT) Unfortunately, the published results of the TRT are methodically frequently bad and scientific of a poor value. Many of the studies presented until now regarding tinnitus retraining therapy are not informative in their scientific context. In a study with 95 patients with a chronic tinnitus TRT could show a significant, more than six months lasting stable success by comparison to a combination of TET with group behaviour therapy (improvement be achieved around at least ten points in the tinnitus questionnaire (TF)). AD 5: PHARMACOLOGICAL THERAPIES Rheological drugs (medicines for hemodilution) could not show any statistically significant effect in the treatment of tinnitus. Studies to the medical treatment with tocainides (lidocaine) showed repeatable positive effects on tinnitus in higher dosages (as of 1.2 mg/day). Lamotrigine as a medicine had an effect positively only at with a small fraction of patients. Two studies with GABA receptor agonists could not prove therapeutic effects for tinnitus. Undesired side-effects were observed. Injections with Carvoverine (a glutamate antagonist) achieved significantly successes with a special form of tinnitus, the "Cochlear-synaptic tinnitus (CST)". A tricyclic antidepressant (Amitriptilin) could prove superiority against placebo. This effect could be confirmed in another study. However Clonazepame (a benzodiazepine), could not achieve any improvement. Short-term improvements were achieved with other benzodiazepines (Clonazepame, Diazepam, Flurazepame, Oxacepame and Alprazolame). A German retrospective study suggests a graded pharmacological therapy by means of rheological infusion therapy, applications of neurotransmitters, and injections of lidocaine. This method achieved a disappearance or a recovery of the complaints at 95.3% of the acute and 26.7% of the chronic cases. AD 6: SURGICAL PROCEDURES The effects of the operative excision of the stapes (stapedectomy) showed significant effects concerning tinnitus. This method is a routine operation to recover hearing, effects on tinnitus were observed only coincidently. There are generally high frequencies of improvements of tinnitus after cochlea implantations; however the risk of deterioration is present with this method. AD 7: OTHER AND ALTERNATIVE THERAPY PROCEDURES The hyperbaric oxygen therapy can be considered successful after acute events with tinnitus. The therapy should be started in the first month after appearance of the tinnitus. The methods transcranial-, electromagnetic and transcutaneous nerve stimulations did not show any significant effects on tinnitus. Also low laser medical treatment showed disappointing effects. The "pneumatic external contra-pulsation" is described as an unproblematic usable procedure by the authors of the examination, but 10% of the patients had to stop the medical treatment because of complications associated with the medical treatment. Acupuncture showed significant improvements in comparison to medical treatment. The effectiveness of this therapy could not be reproduced in another study. Five other studies between 1993 and 1999 also did not show any therapeutic effect of this method. Gingko-Biloba preparations did not show any positive effects in large-scale studies on tinnitus. DISCUSSION: Neither the diagnostic procedures nor the therapeutic methods or the individual therapies reach a usual scientific level in medicine. Unsolved problems concerning insurance, economic as well as legal problems have resulted for the patients and for caring stuff from this unsatisfactory situation. Numerous competitive tinnitus emergence models led to an incredible creativity in trying out different therapy approaches. No convergence of the therapy procedures can be seen within the last decades of tinnitus research, contrariwise there is always more and more "creativity" of new approaches. Priority has to be given to find the cause of tinnitus since therapies are a consequence of a better understanding of these symptoms that evidence oriented investigations on an usual scientific level can be started. CONCLUSION: The innumerable therapeutic approaches, seeming completely incoherent to their effects should be coordinated on the meaningfulness, on the success parameters and with patient safety in light of the most plausible explanation models for non-specific chronic Tinnitus. To this the facilities of competence centres or related science- directing facilities are recommendable. Examinations which are carried out also with small numbers show often methodical insufficiencies. It is necessary that minimal requirements on a scientifically clinical experiment, such as design, case number calculation, analytic statistics, control group, are fulfilled. It is recommendable, that further research has to be promoted regarding tinnitus causes that a coordinated evidence-orientated treatment will be developed.

Cognitive training for dementia.

The aim of the HTA report is to evaluate the effectiveness of cognitive training methods to treat cognitive disorders of dementia and other diseases with cognitive deficits. For this purpose, a systematic literature search was carried out first based on the DIMDI superbase retrieval. The identified publications were judged and selected by two independent, methodically competent experts. 33 publications were included in the report.Based on the studies for a normal cognitive development in old age a theory that healthy older people have a considerable capacity reserve for an improved performance in abstract abilities of thinking can be assumed. The first symptoms for older people at risk for dementia are a reduced cognitive capacity reserve. Cognitive training methods therefore focus abilities of abstract memory.APART FROM TYPES OF DEMENTIA ANOTHER TWO GROUPS OF DISEASES WITH COGNITIVE DEFICITS WERE INCLUDED IN THE HTA REPORT: cerebral lesions and schizophrenic psychoses.Studies with mild as well as forms of dementia heavy forms including the Alzheimer disease were included. The described training methods were very heterogeneous with regard to their contents, the temporal sequence and the outcome parameter. The studies were methodically partly contestable. Approximately a third of the studies of all publications could show improvements in the cognitive achievements by the training.Three studies concerning cognitive training methods in case of cerebral lesions were included. All three studies demonstrated a significant improvement in the training group in some outcome parameters.Special cognitive training methods were used for the treatment of cognitive deficits at schizophrenic psychoses. The neurocognitive training (NET), the "Cognitive Remediation Therapy" as well as the strategic training with coaching proved to be effective. The studies, however, were hardly comparable and very heterogeneous in detail.Summarising the cognitive training methods in case of severe dementia by reality orientation training (ROT) show selected success. In case of cerebral lesions in combination with schizophrenic psychoses successes could be proved in some parameters by applied cognitive training.Considering the heterogenity and the methodical deficiencies of the included studies it can be recommended, to carry out coordinated further studies with the goal to identify the success parameters of cognitive training methods and work out the relevant factors of effectiveness.