Pain during prophylaxis treatment elicited by two power-driven instruments

BACKGROUND: Sonic scalers have an elliptical and piezoceramic ultrasonic scalers a linear oscillation pattern. Thus, a sonic scaler "hammers" the tooth surface, irrespective of its alignment to the tooth, whereas a piezoceramic ultrasonic scaler may oscillate parallel to the tooth surface and gently remove calculus if the alignment is correct. The aim of this study was to measure pain on a visual analogue scale (VAS) during removal of supragingival calculus on mandibular incisors with a sonic or an ultrasonic scaler. MATERIAL AND METHODS: Seventy-four periodontally healthy subjects with supragingival calculus on the mandibular incisors were treated with both a sonic and a piezoceramic ultrasonic scaler in a split-mouth design. The sequence of instrument application and allocation of instruments to jaw side were randomized. Patient comfort was assessed with a VAS after treatment. RESULTS: The VAS results did not show any difference between the two instrumentation modalities. CONCLUSION: For calculus removal during prophylaxis the type of power-driven instrument does not seem to have an impact on perceived pain. This means that the oscillation pattern does not influence the pain experience.     

Variability of sonic scaling tip movement

Abstract The sonic sealer operates at frequencies of 2 to 6 kHz and is powered by pressurised air from the dental unit. Variables likely to affect how these instruments perform include the air pressure input and load applied by the operator. Other variables include the brand of sealer used and the clinical technique of the operator. The aim of this study was to investigate differences in instrument performance within a dental teaching hospital. Light microscopy was used to measure the displacement amplitudes in air of 32 Sonic sealers which were in regular clinical use in three departments (Periodontal Unit, Restorative Unit and School of Hygiene). During operation, the air pressure was kept at a constant 2.8 kg cm^?2and measurements were made on each instrument with three scaling tips (universal, sickle and periodontal). The periodontal scaling tip exhibited the greatest vibration although this was not significant (p>0.1). There was a significant difference in performance between the different clinical environments where the sealers were used (P<0.01). 4 new sonic scaling instruments made by different manufacturers were selected for displacement amplitude measurements. One brand of sonic sealer demonstrated a significantly greater displacement amplitude in comparative measurements between instruments (P<0.01). This study demonstrated differences in the oscillation of sonic sealers which should be recognised by clinicians when using these instruments, since they may influence clinical performance.     

Effectiveness of subgingival instrumentation with power-driven instruments in the hands of experienced and inexperienced operators

Abstract 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 sealer 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.     

Factors affecting the wear of sonic files

Abstract The aim of this study was to investigate (actors affecting; the wear and culling ability of sonic files. A model system was used and the following variables evaluated, file type; Heliosonic, Rispisonic or Shaper, load; 25. 50 or 100 grams and length of time in use; new, 30 or 60 seconds. A 3³ full factorial analysis with two replications into the effect of the above variables on the culling ability of the Heliosonic, Rispisonic and Shaper files powered by the MM 1500 sonic instrument was performed. A new file size 25 (Heliosonic and Shaper) or No 3 (Rispisonic) was used for each cut together with water irrigation and the substrate used was 1 mm thick sections of bovine bone. All variables bad a significant effect on culling (ANOVA, p<0.001). However examination of the F values showed that the most significant variable was load, followed by file type, and time. The most significant interaction was between file type and load followed by lime and file type. The interaction between time and load was not significant (p>0.05). The Rispisonic file was most susceptible to wear during use especially at higher loads and the Heliosonic file cut least. It is suggested that the Shaper file is the better design of the three with respect to cutting ability and wear with use.     

The Effect of Sonicated Serum on Growth of Normal and Leukaemic Human Cells in Agar Cultures

The existence of circulating factors in blood of possible importance for granulo-poiesis was investigated by examining the effect of sonicated serum on agar cultures of human haematopoietic cells. Ultrasound treatment of serum can activate enzymes normally bound to carrier proteins. In normal bone marrow cultures, growth was inhibited by sonicated serum when the cells were cultured in a single layer without exogenous colony-stimulating factor (CSF) included in the culture, while an enhancing effect with a 2–5 fold increase in the number of colonies was seen in feeder layer-stimulated cultures. Morphologically, in contrast to the normal change to eosinophils and monocytes-macrophages during the culture period, the cultures with sonicated serum added showed continuous growth of neutrophils and no increase of other cell types. Experiments using tritiated thymidine indicated that the enhancing effect of sonicated serum involved marrow cells which were more prone to thymidine S-phase kill. The effect of sonicated serum was further evaluated in cultures from patients with leukaemia. In AML in relapse, feeder-layer stimulated cultures of bone marrow cells were inhibited (11/14 cases) by sonicated serum, while reversion to the normal enhancing pattern was seen for patients in remission.     

Instrumentation of furcation with modified sonic sealer inserts A study on manikins (II)

Abstract. We developed a sonic sealer 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 sealer tips with normal handle and (iii) diamond-coated sonic sealer 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 substanee 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 lips 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.     

Effectiveness and safety of a sonic vibratory endodontic instrument

Abstract An air-driven sonic vibratory handpiece to which specially designed K-type files are attached has been developed. When activated, the root canal instruments will vibrate in a whirling motion, and when moved up and down, will abrade the root canal wall. The sonic system was tested in simulated root canals in plastic blocks and in usage tests in dogs' teeth. Forty-nine roots in 3 dogs were divided into 3 groups. Two of the groups were instrumented with the sonic device under continuous irrigation with 2.5% NaOCl or 15% EDTA. The 3rd group was treated with conventional chemomechanical instrumentation and 2.5% NaOGl. The teeth were then extracted, fixed and split in a longitudinal direction and the root canals examined in the scanning electron microscope. After hand instrumentation and sonic instrumentation using NaOCl for irrigation, the canal wall was covered by a smear layer and dentin chips and occasional tissue remnants were seen. An extraoral fine mist of NaOCl was seen during continuous irrigation with this medicament, causing eye soreness in the operator. Continuous irrigation with EDTA during sonic instrumentation removed the smear layer and gave clean canal walls. The vibratory files appeared safe and size 20 followed curved canals well. The effectiveness of the sonic device was similar to hand instrumentation. It considerably improved the ease and, to some extent, the speed of root canal instrumentation.     

Bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation

Abstract The purpose of this study was to assess the bacteriologic status of the root canal after sonic, ultrasonic and hand instrumentation. Root canal infection was induced in 50 single-rooted teeth in young dogs by removing the pulp and filling the canals with dental plaque. After 7 clays the root canals were instrumented under aseptic conditions with conventional hand instruments, a sonic vibratory device or an ultrasonic device. Sterile saline or 2.5% sodium hypochlorite was used as irrigating solution. Following instrumentation a sterile paper point was sealed into the root canals. After 7 d the root canals were reopened under aseptic conditions and the paper points were incubated for the demonstration of bacteria, using pre-reduced thioglycolate culture medium and anaerobic chambers. The results obtained with the different instrumentation techniques and irrigating solutions were compared by means of the Chi-square test. The results indicated that the sonic and ultrasonic devices were not more effective in the elimination of bacteria from the root canal than conventional hand instrumentation. Irrigation with sodium hypochlorite appeared to be more effective than saline in producing bacteria-free root canals; however, this difference was not statistically significant. Thus, it appeared that more than one appointment and the supporting action of an antibacterial medicament between appointments would be necessary to achieve bacteria-free root canals in infected teeth in a predictable manner.