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.

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.

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.

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.

Retrospective comparison of clinical variables between compliant and non-compliant patients.

BACKGROUND: The aim of this retrospective study was to evaluate if patients with moderate to advanced periodontitis had comparable periodontal conditions at baseline and during supportive periodontal therapy (SPT) whether they were compliant or not. METHOD: Patient-related variables were compared: age, tooth mobility, furcation involvement, number of teeth, pocket probing depth, plaque index. Compliant patients (n = 142) received complete periodontal treatment and were followed over at least 10 years (group A). Non-compliant patients either discontinued supportive periodontal therapy (n = 42, group B) or dropped out before or during periodontal surgery (n = 44, group C). RESULTS: At baseline, there were no significant differences between the 3 groups except for mobility. During SPT, mean pocket probing depth and plaque index differed significantly. CONCLUSION: These results indicate that non-compliant patients compared to compliant patients had similar periodontal conditions at baseline, but responded less favourably to periodontal surgery and maintenance.

Disease progression in periodontally treated and untreated patients--a retrospective study.

BACKGROUND, AIMS: The aim of this retrospective study was to assess the effect of regular supportive periodontal treatment on disease progression in patients with moderate to advanced periodontitis. METHOD: We compared radiographic change of interdental bone level and number of teeth at 2 time points in 3 patient groups (mean age 46 years): group A, periodontally untreated patients (n= 14) who dropped out during initial therapy; group B, non-compliant patients (n=26), who discontinued supportive periodontal therapy after ca. 2 years of maintenance; group C, compliant patients (n=27), who regularly attended the maintenance program for 7 years. Periodontal treatment was performed as scaling and root planing or flap surgery in groups B and C. All 3 groups were re-examined ca. 7 years after the initial examination. RESULTS: Patients in group A lost 3.8 teeth (0.5 teeth/year), those in group B 3.2 (0.4 teeth/year), and in group C, patients lost 2.0 teeth (0.2 teeth/year). About half of the patients lost no teeth (group A 43%, B 42%, C 55%), and only 17 subjects lost more than 3. At the 2nd examination, an increase in interdental bone was found only in group C (+0.13 mm), while groups A and B lost 0.57 mm and 0.31 mm of alveolar bone level, respectively (p<0.05 group C versus A and B). CONCLUSIONS: Systematic periodontal treatment stops interdental bone loss and decreases the rate of tooth loss in most cases. Periodontal surgery without regular follow-up care cannot prevent further periodontal destruction, but it can delay it.

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.

A study on the imaging of complex furcation forms in upper and lower molars.

BACKGROUND, AIMS: The form of the molar roots and their furcated region influence both the pathogenesis of periodontal destruction and therapeutic attempts. METHOD: Using a specially-constructed measuring device, 359 1st and 2nd molars, both upper and lower, were analysed 3-dimensionally. The parameters measured were horizontal furcation concavity, height of root trunk, degree of root taper, the distance between the root prominences adjacent to the furcation entrances and the angle of root separation. RESULTS: The mean horizontal furcation concavity in lower molars was 0.5 mm at a distance of 1 mm apical to the cemento-enamel-junction (CEJ) and 3 mm at the distance of 4 mm apical to the CEJ. The angle of root separation was between 16 degrees (lower jaw molars lingual) and 29 degrees (upper jaw molars distal). The vertical distance from root separation to CEJ averaged 3.3 mm in lower jaw molars and 4.8 mm in upper jaw molars. CONCLUSIONS: Our findings underline the variability of furcation morphology.

Root debridement of molars with furcation involvement using diamond-coated sonic scaler inserts during flap surgery -- a pilot study.

In our laboratory, we modified sonic scaler inserts to increase effectivity of root surface instrumentation of molars with furcation involvement during flap surgery. The working end of conventional sonic scaler inserts was thickened ellipsoidally and diamond coated. Inserts with variously angled shafts were designed in order to facilitate insertion into the furcation. A clinical, split-mouth study examined the debridement of molars with furcation involvement during flap surgery using either hand instruments or diamond-coated sonic scaler inserts with 15 patients. Average treatment time was cut by ca. 50%, using diamond-coated inserts as compared to hand instruments for root surface debridement during surgery. 2 years after surgery, the clinical parameters had not been influenced by type of instrument used.

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.

Root debridement of single-rooted teeth with a diamond-coated sonic scaler insert during flap surgery. A pilot study.

In our laboratory, we modified inserts of a sonic scaler to increase effectivity of root surface instrumentation during flap surgery. The present clinical study investigates whether use of this diamond-coated, thickened insert facilitates more rapid root debridement compared to hand instruments and whether clinical wound healing is influenced by the type of instrument used. In 13 patients with moderate to advanced periodontal destructions, flap surgery was carried out on single rooted teeth with probing depth of > or =6 mm. The mean amount of time saved by root debridement with the diamond-coated insert was 60% over curets. Regardless of the used instrumentation method probing depths and attachment level changes were altered and remained unchanged for 2 years after surgery. In conclusion the newly-developed, diamond-coated sonic scaler insert facilitates more rapid root debridement during flap surgery than hand instruments without disadvantageously affecting clinical healing.

Changes in the periodontal membrane due to apical periodontitis.

Teeth with an apical inflammatory lesion were studied by light microscopic morphometrical procedures to estimate the volumetric density of periodontal ligament tissues by point counting. Sixty-four root surfaces were investigated from coronal to apical. The observed tissue changes were similar in groups with and without bacteria, except for an elevated volumetric density of inflammatory cells in the first group. The attachment was lost apically. Principal fibers running to the root surface and extensions in the cementum decreased from coronal to apical, but were replaced by fibers running parallel to cementum and fibers oriented in a network. We suggest that acellular extrinsic fiber cementum was lost, whereas cellular mixed stratified cementum was built. The cellular mixed stratified cementum synthesis was by inclusion of the remaining fibers from the acellular extrinsic fiber cementum. We suspect that the changes were the result of the anti-inflammatory reaction caused by the periapical lesion.

Instrumentation of furcation with modified sonic scaler inserts: study on manikins, part I.

The purpose of this study was to determine the suitability of different scaling instruments for the debridement of furcations. 12 upper and 12 lower replicated molars with through-and-through furcations were instrumented 3x with 5 different types of instruments: (i) hand instruments; (ii) hand instruments in conjunction with diamond burrs; (iii) a conventional ultrasonic scaler insert; (iv) a conventional sonic scaler insert; (v) a set of 2 modified diamond coated sonic scaler inserts with different angulated shafts. The plastic replicas were fixed in a manikin head without replicated soft tissues. Following debridement, weight loss and % of instrumented furcation area were assessed. In the case of lower molars, it made little difference whether they were treated with hand instruments, hand instruments combined with diamond burrs, or diamond-coated sonic scaler inserts. On upper molars, however, significantly more area was instrumented with the diamond-coated inserts than with the other instruments. Substance removal was greater with diamond-coated inserts than with the other devices. In conclusion, an effective debridement of the furcation seems possible only with an odontoplasty, in which a furcation is fitted to the instrument by means of intensive instrumentation, thus leading to substance loss. To improve results with these instruments, further research is necessary.

Instrumentation of furcation with modified sonic scaler inserts: a study on manikins (II).

We developed a sonic scaler tip with an ellipsoid diamond-coated bud and contra-angulated shafts to overcome problems resulting from furcation anatomy. In this study, extracted molars were instrumented in a dummy model without any replicated soft tissues using 3 different instrumentation methods (i) curettes, (ii) diamond-coated sonic scaler tips with normal handle and (iii) diamond-coated sonic scaler tips in 2 handles with varying power levels. 15 extracted upper and lower molars were instrumented using each of the 3 instrumentation types. Following debridement, loss of substance and % of furcation area instrumented were assessed. In both upper and lower molars, significantly more surface area was instrumented in one instrumentation run with diamond-coated tips than with curettes. Substance loss was greater with diamond-coated tips than with hand instruments. In conclusion, an effective debridement of the furcation roof seems only possible with odontoplasty. Clinical evaluation of this approach to root debridement is needed.

The diamond-coated sonic scaler tip. Part I: Oscillation pattern of different sonic scaler inserts.

The authors have developed a set of four modified sonic scaler inserts with variously shaped shafts and diamond-coated budded inserts. The inserts are specially designed for the furcation area since instruments used hitherto have not been successful in completely preventing slow continuous periodontal breakdown in multirooted teeth. To test their clinical effectiveness, the displacement amplitude of the different sonic scalers was measured under varying load applications. Each scaler insert generated different and characteristic displacement amplitudes from rest position. The conventional insert was continuously dampened under increasing load application, whereas the diamond-coated inserts showed only minor variations of oscillation pattern. In a clinical situation, both insert types should be used, with the least possible application load to maintain effectiveness and minimize removal of hard tissue.

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.

A clinical study comparing two high-fluoride dentifrices for the treatment of dentinal hypersensitivity.

Amine fluoride, the active ingredient of a currently marketed dentifrice in Germany and other European countries, and sodium fluoride were compared to a placebo dentifrice for their effectiveness in alleviating dentinal hypersensitivity. This was a randomized, double-blind, two-center, parallel clinical study covering 8 weeks of product use by 115 subjects. The hypersensitivity of the affected teeth was assessed by tactile stimulation, cold air stimulation, and overall subjective patient response. The three treatment groups exhibited comparable baseline sensitivity. These three methods of clinical assessment demonstrated that the desensitizing ability of a relatively higher fluoride dentifrice (1,400 ppm), delivered either as amine fluoride or sodium fluoride, did not differ significantly from that of the placebo dentifrice.

Debridement by operators with varying degrees of experience: a comparative study on manikins.

The treatment of periodontally diseased root surfaces with power-driven instruments is becoming increasingly important as an alternative to the use of hand instruments. Root surfaces of artificial teeth on a manikin were debrided under simulated flap operation conditions to determine if effectiveness was dependent on the instrument used (curettes or a modified sonic scaler tip) and/or the operator's degree of experience. Two quadrants were treated with each instrument. A morphometric evaluation followed. Debridement was faster with the diamond-coated sonic scaler tip than with hand instruments. With the sonic scaler, the time necessary for treatment was reduced by 30%. The experienced operators treated about 80% of the root surface, while the inexperienced operators treated only about 65%. Treatment quality depended on the operator and not on the instrument used.

The diamond-coated sonic scaler tip. Part II: Loss of substance and alteration of root surface texture after different scaling modalities.

The authors have developed a set of four modified sonic scaler inserts with variously shaped shafts and diamond-coated budded inserts. The inserts are specially designed for the furcation area since instruments used hitherto have not been successful in completely preventing slow continuous periodontal breakdown in multirooted teeth. To improve understanding of their clinical effectiveness, instrumentation of dentin samples was done with a curette as well as conventional and modified sonic scaler inserts under standardized conditions. The results showed that significantly greater amounts of tooth substance were removed with the diamond-coated airscaler tips than with the conventional tip. The depth of substance removal was comparable to that obtained with hand instruments and increased with application force. Although differences in surface texture were found among the different modes of scaling, it remains to be determined whether they are of clinical significance.

Heat propagation in dentin during instrumentation with different sonic scaler tips.

It is important to know how much heat is generated when a root surface is debrided with sonic scalers and if that heat can be released satisfactorily into the environment. The temperature changes that occurred in dentinal specimens treated with two different sonic scaler tips, used with and without coolant, were studied. Temperature increases of up to 4 degrees C were observed for both tips when a coolant was used. Heat propagation during instrumentation was dependent to a considerable degree on the temperature of the coolant. Sonic scalers should not be used without coolant, because the dentinal temperature may increase up to 35 degrees C, depending on the force of application. A high positive linear correlation was found between increase in temperature and force of application.