PubMed Health⌕ Search

Biomedical subjects

A Rühling

Publications and source records attributed to A Rühling.

14 recordsLinked to original sources
PubMed2004

Surface wear on cervical restorations and adjacent enamel and root cementum caused by simulated long-term maintenance therapy.

BACKGROUND: In an in vitro study, the surface wear on cervical restorations and adjacent enamel and root cementum caused by different tooth-cleaning methods in simulated long-term therapy was investigated. METHODS: Cervical restorations of amalgam (Oralloy), modified composite resin (Dyract), glass-ionomer cement (ChemFill Superior), and composite (Tetric) were instrumented by POL (polishing), CUR+POL (curette and polishing), US+POL (ultrasonic device with polishing) and the polishing agents Cleanic and Proxyt in a computer-controlled test bench. Treatment time corresponding to a real-time period of 5 or 10 years. Substance loss from instrumented surfaces was measured with a digital gauge. A three-way anova was used in the statistical evaluation. RESULTS: The results showed that POL led to slight substance loss, which was greater using Cleanic (27 microm) than Proxyt (5 microm). CUR+POL produced a significantly greater substance loss than did US+POL, with 186 microm versus 35 microm on glass-ionomer cement, respectively, and 123 microm versus 18 microm, respectively, on root cementum, followed by composite (111 microm versus 27 microm, respectively), polyacid modified composite resin/compomer (89 microm versus 36 microm), amalgam (75 microm versus 19 microm), and enamel (32 microm versus 23 microm). CONCLUSIONS: As opposed to the use of US+POL or POL, substance loss on cervical restorations and especially root cementum must be expected to result from tooth-cleaning during long-term maintenance treatment using CUR+POL.

Analysis of Variance↗
PubMed2003

Learning root debridement with curettes and power-driven instruments. Part II: Clinical results following mechanical, nonsurgical therapy.

BACKGROUND, AIMS: In a manikin study we recently assessed how effectively student operators were able to learn scaling with curettes (GRA) and power-driven instruments (PP). Calculating the debrided root area effectiveness was low in both groups without systematic training or without a motivational program. After 10 weeks (20 h) of training, operators reached a high effectiveness of 84.7% (GRA) and 81.6% (PP). The purpose of the present study was to evaluate the clinical outcome of nonsurgical treatment as performed by these student operators. METHODS: In a clinical trial, 19 students trained in the use of Gracey curettes for 10 weeks (=20 h) (GRA10) and Periopolisher system for 1 week (=2 h) (PP1), and 20 students trained in the use of Gracey curettes for 1 week (GRA1) and the Periopolisher for 10 weeks (PP10) treated one patient each in a split-mouth design. At baseline and 6 months, we recorded probing depth (PD), probing attachment level (PAL) and bleeding on probing (BOP) by computer-assisted probing. Statistical analysis was carried out for moderate (category B) and deep sites (category C). Groups were compared using Student's t-tests (p<0.05). RESULTS: Category B sites showed a PD reduction of 1.2/1.0 mm (GRA10/GRA1) and 1.1 mm (PP10/PP1). PAL gain was 0.5/0.3 mm (GRA10/GRA1) and 0.4/0.2 mm (PP10/PP1). In category C sites, PD reduction was 2.1/2.3 mm (GRA10/GRA1) and 2.0 mm (PP10/PP1) with a PAL gain of 0.6/0.9 mm (GRA10/GRA1) and 0.4 mm (PP10/PP1). BOP was significantly lower in all groups. CONCLUSION: The results show that student operators who had received a systematical training on manikins and had attained different effectiveness results were able to treat periodontally diseased patients successfully using both Gracey and Periopolisher instruments.

Dental High-Speed Equipment↗
PubMed2002

Learning root debridement with curettes and power-driven instruments. Part I: a training program to increase effectivity.

BACKGROUND/AIMS: In a dummy-head trial, we assessed how effectively untrained operators were able to learn scaling with curettes and power-driven instruments. METHODS: Two untrained operator groups (n = 11 each) received six 2-h lessons during a 10-week period following a training program. Subgingival scaling was performed with curettes (GRA) and a power-driven system (PP). At 6 test days each subject had to instrument 10 test teeth. The percentage of debrided area was assessed with an image analysis program. Learning success was measured as a percentage of debrided root area and scaling time. Furthermore, the effectivity was related to difficulty in anatomical situations and access to root surfaces. Statistical analysis was carried out with SPSS. RESULTS: At baseline, effectivity was 63.1% (GRA) vs. 52.3% (PP). Between weeks 9 and 11, operators reached a plateau for group GRA at 84.7% and group PP at 81.3%. Scaling time did not differ between the two groups. Debridement of teeth with complex root shapes that were hard to access was less effective with the power-driven system. CONCLUSION: Independent of the instrument used, untrained operators were only able to debride root surfaces at low levels of efficacy. With systematical training, effective scaling with the power- driven system was as easy to learn as with hand instruments. On root surfaces with complicated shape and anatomy or difficult accessibility, the power-driven system works significantly less effectively.

Alveolar Bone Loss↗
PubMed2002

Learning root debridement with curettes and power-driven instruments in vitro: the role of operator motivation and self-assessment.

The influence of systematic dummy-head training with Periopolishe (PP, group A) and Gracey instruments (GRA, group B) on the effectiveness of root debridement was evaluated by Rühling et al., 2002 (9). Their results indicate that independent of the instrument used, untrained operators were only able to debride root surfaces at low levels of effectiveness. It was possible to increase effectiveness to a high level through systematic training in both groups. The aim of the present study was to assess the role of operator motivation and self-assessment on scaling effectiveness. Before baseline, operators were asked to answer a questionnaire rating the expectation of the instrument performance. Four groups of inexperienced operators (n = 11 each) received 10 weeks dummy-head training. In groups A (GRA) and B (PP), training was combined with a motivational programme. Groups C (GRA) and D (PP) received the same training, but no additional motivational programme. In a dummy-head, 10 test teeth were debrided and operators were asked to estimate their effectiveness of debridement at each test day. Effectiveness was calculated as percentage of debrided root area on 10 test teeth at different time points with an image analysis programme (NIH Image) and ANOVA. Two groups were compared using the Mann-Whitney U-test (unpaired) and the Wilcoxon signed ranks test (paired). Motivated groups (A and B) reached about 25% higher debridement results (p < 0.001) and were able to estimate their effectiveness more precisely compared to groups C and D. In the low motivation groups (C and D), overestimation of more than 20% was evident (p < 0.001). The questionnaires revealed underestimation of the GRA instruments and overestimation of PP instruments. Operator motivation and self-assessment greatly influence learning of effective root debridement.

Analysis of Variance↗
PubMed2001

Removal of HA and TPS implant coatings and fibroblast attachment on exposed surfaces.

The removal of implant coatings may be necessary if rough implant surfaces are exposed subgingivally due to progressive peri-implant bone loss or if they are also supragingivally exposed because of progressive gingival recession, thus facilitating plaque formation and impairing tooth cleaning done at home. The aim of this experimental study was to develop diamond-coated files and rubberized polishers for machine-driven instrumentation of implant cylinders, and present an instrumentation concept for the complete removal of rough titanium plasma spray (TPS) and hydroxylapatite (HA) layers and polishing exposed titanium surfaces. The surface structure and its possible contamination by the instrumentation process was investigated using laser profilometry, scanning electron microscopy, and x-ray fluorescence analysis. The effect of impurities on the growth of human fibroblasts was tested in cell culture. The results show that TPS and HA implant coatings can be removed with the modified implant files. After polishing the exposed titanium surfaces, roughness depths of Rz=4.6 microm (TPS) and Rz=5.7 microm (HA) and, for implant cylinders, 3.4 microm were found. During the instrumentation of implant surfaces, contamination with the material of the instrument must be expected. It was shown that, in principle, growth of human gingival fibroblasts on the instrumented surfaces is possible. The cells were intimately associated with one another and, compared to culture controls, demonstrated good adhesion with strict orientation to the microstructure of the scoring left by instrumentation. The biological consequences and mechanisms of cell adhesion on instrumented surfaces require further investigation.

Cell Adhesion↗
PubMed2001

Subgingival polishing compared to scaling with steel curettes: a clinical pilot study.

BACKGROUND: Recently, we have developed teflon-coated sonic scaler inserts which remove plaque without removing tooth substance; they polish subgingivally. In a preclinical test, we showed that these modified inserts remove plaque nearly as effectively as do conventional sonic scaler inserts. The present investigation was intended as a proof-of-principle of subgingival polishing. The aim was to study the effect of subgingival polishing on the resolution of gingival inflammation in comparison to conventional scaling. MATERIAL AND METHODS: In 10 patients with moderate to advanced periodontal disease, who had at least 2 single-rooted teeth with a probing depth of >6 mm in each quadrant, all single-rooted teeth were subjected to one treatment regimen consisting of 2 instrumentation episodes (1st/2nd treatment): curette/curette, curette/teflon-coated sonic scaler, teflon-coated sonic scaler/teflon-coated sonic scaler, and an untreated control. The second treatment session was performed 3 months after the first instrumentation, and the final registration 3 months after the second instrumentation. Clinical measurements included probing depth, change of clinical attachment level, bleeding upon probing, and plaque scores. RESULTS: Probing depth, attachment level, and bleeding scores were reduced in the 3 instrumentation groups versus the control group in the 1st period; in the 2nd period, no further change occurred. Subgingival polishing with teflon-coated sonic scaler inserts was slightly less effective than conventional scaling. CONCLUSION: Subgingival polishing with teflon-coated sonic scaler inserts seems to be nearly as effective as conventional scaling. Thus, it may be the instrumentation of choice for maintenance treatment of residual pockets.

Adult↗
PubMed2000

Subgingival polishing with a teflon-coated sonic scaler insert in comparison to conventional instruments as assessed on extracted teeth. (I) Residual deposits.

BACKGROUND: Recent studies have shown that endotoxins are located on the periodontally diseased root cementum and not within it. These studies led to the suggestion that the root surface could be treated less aggressively during periodontal therapy. Thus, we designed a teflon-tubed sonic scaler insert for subgingival polishing. It was our objective to assess to which extent this new instrument is capable of removing bacterial deposits in deep pockets in comparison with conventional scaling instruments. METHOD: We compared the extent to which plaque and calculus could be removed with a curette, a conventional sonic and ultrasonic scaler insert, a Per-io-tor insert, and a teflon-tubed sonic scaler insert. 84 teeth requiring extraction had been treated with one of these instruments. After extraction, the teeth were stained with Malachite green, and the following areas were assessed: area lacking plaque and calculus, calculus, and area only covered with plaque. For statistical comparison, nonparametric analyses were carried out. RESULTS: Curettes and conventional ultrasonic and sonic-scaler inserts had more area lacking plaque and calculus (97.5%, 92.2%, 92.1%) than did the Per-io-tor (80.1%) or the teflon-coated sonic scaler insert (84.4%). A similar effectivity sequence was observed for residual soft deposits (curette: 1.9%, ultrasonic scaler: 6.1%, sonic scaler: 5.4%, teflon-coated sonic scaler: 5.1% and Per-io-tor: 9.5%). CONCLUSIONS: The Per-io-tor and the teflon-coated sonic scaler insert seem to be suitable for the removal of soft deposits on the root surface, but not for the removal of calculus.

Adolescent↗
PubMed1997

Effectiveness of subgingival instrumentation with power-driven instruments in the hands of experienced and inexperienced operators. A study on manikins.

Power instrumentation of periodontally-diseased root surfaces is gaining in significance as an alternative to conventional curette methods. In an experimental study employing manikins with simulated bone loss, we investigated whether inexperienced and experienced operators were able to achieve greater therapeutic success with power-driven devices than with hand instruments in subgingival scaling. 10 dentists experienced in periodontal treatment and 10 inexperienced dentists instrumented 7 teeth in the upper jaw, which had been covered with artificial deposits. Hand instruments, the Perioplaner system, a sonic and an ultrasonic scaler were used. The time required for treatment was measured and the % of residual deposits was calculated by means of image-processing techniques. Weight loss was also determined for the teeth that were scaled with the hand instruments and the Perioplaner system. Experienced operators left significantly less % of residual deposits on the teeth (18+/-7.6%) than the inexperienced (27+/-8.4%), regardless of the type of instrument selected. Both experienced and inexperienced operators left the smallest amounts of residual deposits with hand instruments (13+/-9.8%/24+/-9.5%). Both treatment groups removed more hard tooth structure with hand instruments than with the Perioplaner system (53+/-48mg versus 47+/-25.9 mg). Experienced operators needed somewhat more time for debridement than unexperienced. Use of the sonic/ultrasonic device required somewhat less time than hand instrumentation. Inexperienced operators are, however, unable to improve their treatment results by using the power-driven instruments included in the study.

Analysis of Variance↗
PubMed1996

Progressive peri-implantitis. Incidence and prediction of peri-implant attachment loss.

The aim of this prospective study was to characterize an implant patient population exhibiting clinical signs of peri-implantitis and to determine subsequently the incidence of progressive attachment loss. The predictive values of diagnostic parameters were evaluated. 25 patients with 54 endosseous implants that had been loaded for 41 +/- 15 months were included in the study. Clinical parameters included the assessment of plaque, bleeding on probing, probing depth, attachment levels, and Periotest values. Probing measurements were performed in duplicate by means of a controlled force electronic probe (Periprobe). Peri-implant crevicular fluid samples were collected and assayed for neutral proteolytic enzyme (NPE) activity (Periocheck). Analysis of duplicate baseline probing data revealed a high degree of reproducibility (mean difference: 0.1 +/- 0.3 mm). A minimum threshold of 1.0 mm (> 3 x S.D.) loss of probing attachment was chosen to classify a site as positive for breakdown. Alternatively, the tolerance method was employed to identify sites with progressive attachment loss. After 6 months, irrespective of the analytical method, 6 percent of all sites (in 19% of the implants) and 28% of the patients had experienced further peri-implant attachment loss. There were significant differences (p < 0.05) in mean plaque (73% vs. 45%) and NPE (36% vs. 12%) scores between patients with progressive peri-implantitis and those with stable peri-implant conditions. Both bleeding on probing and the NPE-test were characterized by high negative predictive values, and thus negative scores can serve as indicators for stable peri-implant conditions. For monitoring peri-implant health during recall visits, attachment level recordings with a controlled force electronic probe in conjunction with enzymatic diagnostic tests of the host response can be recommended.

Aged↗
PubMed1996

Proof of efficacy of different modified sonic scaler inserts used for debridement in furcations--a dummy head trial.

The purpose of this study was to determine the suitability of different scaling instruments for surgical removal of hard and soft bacterial deposits and for the removal of soft accretions only for maintenance treatment within furcations. 12 upper and 12 lower plastic replicated molars, with through-and-through furcations, were instrumented 3 x with 4 different types of instruments: (1) hand instruments; (2) a conventional sonic scaler insert; (3) a set of 3 modified sonic scaler inserts with budded tips and different angulated shafts; (4) a set of 3 sonic scaler inserts with a plastic-coating and different angulated shafts. The plastic replicas were fixed in a dummy head without any replicated soft tissues. In the furcation area, an easily removable surface coating material was applied to the teeth to represent the "plaque" and a second, more stubborn lacquer layer representing "calculus/cementum". Following instrumentation, the following parameters were recorded to assess efficacy; time required for instrumentation, loss of weight, depth of substance removal at the furcation entrance, % of furcation area instrumented, whereby removal of these 2 layers was judged separately. Only minor differences were observed between hand instruments, conventional and budded sonic scaler inserts as to loss of weight, depth of substance loss and area instrumented. The plastic-coated sonic scaler inserts were just as effective in surface layer removal representing "plaque" as the 3 other instruments, but resulted in less loss of weight and less depth of substance removal. In conclusion, the more aggressive hand instruments, the conventional and budded sonic scaler insert, are preferably used for the surgical phase to increased ease of entry into the furcation dome. An effective debridement of the furcation roof seems only possible with an odontoplastic, for which a furcation is fitted to the instrument by means of an intensive instrumentation, thus leading to weight loss and pronounced substance removal. The plastic-coated sonic scaler inserts seems to be a reasonable choice for maintenance treatment within furcation, since this treatment phase is usually restricted to removal of soft bacterial deposits.

Analysis of Variance↗
PubMed1994

[Sore throat patients as the topic of a general practice quality circle. Determination and development of a practice guideline. Quality Assurance Study group for General Medicine].

UNLABELLED: The present paper describes the institutionalization of a general practitioners' quality circle and the development of management guidelines for the treatment of patients with sore throat. Doctors participating: An invitation to attend an "information meeting" on the subject quality control and a quality circle sent to 200 general practitioners and internists, evoked a response by 18 physicians, ten of whom participated in the first meeting of the quality circle. Practical procedure: Stocktaking of the procedure in the doctor's office on the basis of a documentation questionnaire, the discussion of a video of the counselling of a patient with a sore throat, interviews with patients and the personal experience of the participating physicians was compared with a current analysis of the literature. The results of the comparison were taken as a basis for the development of management guidelines following the Dutch NHG Standard (Nederlands-Huisartsen-Genootschap-Standarden). RESULTS AND CONCLUSIONS: A wide variation was found in the treatment offered to patients with sore throats in the doctor's office. Deviation from text book information does not indicate a priori any quality deficit in the GP's practice. With respect to the management guideline worked out, it was agreed that in the individual case, a wellfounded deviation can be justified.

Family Practice↗
PubMed1994

Treatment of subgingival implant surfaces with Teflon-coated sonic and ultrasonic scaler tips and various implant curettes. An in vitro study.

Removal of plaque and calculus by means of sonic and ultrasonic scalers causes considerable damage to implants. With a view to avoiding the aggressive effects of these instruments, an experimental study was carried out for which conventional sonic and ultrasonic scalers were coated with Teflon. The effects of these instruments on implant surfaces was then compared with that of plastic and metal implant curettes. Stereo-microscopy, scanning electron microscopy and surface profilometry were used to detect and record damage to implant surfaces and changes in surface roughness. Generation and propagation of heat in subgingival simulation of use of sonic and ultrasonic scalers were also recorded by means of temperature measurements at the implant surface. The results revealed that no discernible damage was caused by Teflon-coated sonic and ultrasonic scalers or implant curettes made of plastic on smooth titanium surfaces. Instrument material residues were found on rough implant surfaces. It was not the intention of this study to provide an analysis of the prerequisites for the cleaning of rough implant surfaces, but rather to determine what type of damage is to be expected when contact is made with smooth and rough surfaces unintentionally. Temperature measurements during the subgingival use of sonic and ultrasonic scalers indicated satisfactory functioning of the cooling system. Coating of sonic and ultrasonic scaler tips with Teflon thus facilitates the use of high-frequency instruments to achieve professional cleaning of implants.

Dental Implants↗
PubMedDate not supplied

Longitudinal evaluation of aspartate aminotransferase in the crevicular fluid of implants with bone loss and signs of progressive disease.

Aspartate aminotransferase (AST) has been shown to be a promising host marker for periodontal disease progression. The aim of the present study was to analyze AST in the crevicular fluid (CF) of implants exhibiting peri-implantitis and to evaluate the association between AST levels and progressive attachment loss. Twenty patients who had received a total of 42 endosseous cylindric titanium implants were examined. Radiographic assessment of preexisting bone loss and clinical measurements, including electronic attachment of probing, presence or absence of plaque, bleeding on probing, and AST analysis in CF, were performed on 2 occasions 6 months apart. During this study period 13 of 168 sites in 7 patients experienced further loss of attachment greater than or equal to 1.0 mm (median 1.7 mm; interquartile range 0.4 mm). Evaluation of a positive AST test (> or = 300 microIU) in site-specific diagnosis revealed low positive (8%) and high negative predictive values (92%), with a sensitivity of 15% and a specificity of 83%. These results indicate that, in contrast to periodontal disease, the assessment of AST in peri-implant crevicular fluid may be of limited value as a diagnostic and prognostic marker for peri-implant disease.

Alveolar Bone Loss↗