Advances in power driven pocket/root instrumentation

Ultrasound promoted reaction of Rhodamine B with sodium hypochlorite using sonochemical and dental ultrasonic instruments

The sonochemical acceleration of bleaching of Rhodamine B by sodium hypochlorite has been studied using ultrasound intensities in the range 0-7 W cm(-2). Using a 20 kHz ultrasonic horn, it was shown that ultrasound could significantly shorten the treatment time and/or the concentration of hypochlorite required for the reaction. A number of intermediate species formed during the reaction have been identified. It was demonstrated that the same sonochemical reactions occur during the use of dental ultrasound instruments of the type used in endodontics where hypochlorite solutions act as disinfectants. Results showed pseudo-first order degradation kinetics for the degradation of Rhodamine B for both types of source. Both the distribution of cavitation and the resulting bleaching reactions were dependent on the design of the tips. The bleaching reaction can therefore be used to characterise the behaviour of dental instruments and aid in the optimisation of their performance.

Er:YAG laser treatment in supportive periodontal therapy

OBJECTIVE

To assess clinical and microbiological outcomes of an Er:YAG laser in comparison with sonic debridement in the treatment of persistent periodontal pockets in a prospective randomized controlled multicentre study design.

MATERIAL AND METHODS

A total of 78 patients in supportive periodontal therapy with two residual pockets were included, 58 were available for the whole follow-up period. Root surfaces were instrumented either with a sonic scaler (Sonicflex(®) 2003 L) or with an Er:YAG laser (KEY Laser(®) 3). Clinical attachment levels (CAL), Probing depths (PD), Plaque control record (PCR) and Bleeding on probing (BOP) were assessed at baseline, 13 and 26 weeks after treatment. In addition, microbiological analysis was performed employing a DNA diagnostic test kit (micro-IDent(®) Plus).

RESULTS

Probing depths and CAL were significantly reduced in both groups over time (p < 0.05), without significant differences between the groups (p > 0.05). BOP frequency values decreased significantly within both groups (p < 0.05), with no difference between the laser and the sonic treatment (p > 0.05). PCR frequency values did not change during the observation period (p > 0.05). Microbiological analysis failed to expose any significant difference based on treatment group or period.

CONCLUSION

Employing both sonic and laser treatment procedures during supportive periodontal care, similar clinical and microbiological outcomes can be expected.

Clinical and microbiologic results 12 months after scaling and root planing with different irrigation solutions in patients with moderate chronic periodontitis: a pilot randomized trial

BACKGROUND

The aim of this study is to determine in a randomized trial the impact on treatment outcome after 12 months of different subgingival irrigation solutions during scaling and root planing (SRP).

METHODS

Fifty-one adult volunteers with generalized chronic periodontitis were treated by full-mouth SRP using 0.9% sodium chloride, 0.12% chlorhexidine digluconate, or 7.5% povidone-iodine for subgingival irrigation during SRP. Before SRP and after 3 and 12 months, probing depth (PD), clinical attachment level (CAL), and bleeding on probing (BOP) were recorded. Subgingival plaque samples were analyzed for Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythia, and Treponema denticola.

RESULTS

PD, CAL, and BOP were significantly improved in all groups after 12 months (P <0.001 to P = 0.044). No significant differences were seen among the groups for all sites and sites with 4 to 6 mm PD at baseline. The povidone-iodine group had the highest clinical improvements. The counts of A. actinomycetemcomitans and P. gingivalis were significantly reduced after 12 months (P = 0.045 and P = 0.002) using povidone-iodine. Significant differences between the groups were seen after 3 months for A. actinomycetemcomitans and P. gingivalis, and after 12 months for T. forsythia.

CONCLUSIONS

No differences were seen among the groups in the clinical results after 12 months. Regarding the microbiologic results, a slight benefit seemed to derive from the use of povidone-iodine.

Efficacy of Er:YAG laser in the treatment of chronic periodontitis: systematic review and meta-analysis

Scaling root planing (SRP) has been proven efficacious as the traditional treatment approach for chronic periodontitis. However, important limitations such as difficult access in deep pockets, grooves, and furcations have led to the development of new therapeutic strategies. The erbium-doped:yttrium-aluminium-garnet (Er:YAG) laser is one of the most promising laser types for periodontal therapy. Its efficacy in radicular debris removal and root smoothing has been proven in vitro. However, the clinical effectiveness of the Er:YAG laser remains controversial. The aim of the present systematic review was to systemically assess the scientific evidence for the effectiveness of Er:YAG laser compared to SRP in the treatment of chronic periodontitis. Electronic database searches of MEDLINE, Cochrane Controlled Clinical Trial Register, Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effects, CINAHL, Science Direct, ISI Web of Science, and SCOPUS were performed, as well as hand-searching of relevant journals through December 23, 2010. Quality assessment was made according to the CONSORT guidelines. The systematic review was performed according to the QUOROM statement and Cochrane Collaboration recommendations. Meta-analyses of the clinical attachment level gain, probing depth reduction, and changes in gingival recession were performed using weighted mean differences for continuous data with 95% confidence intervals, nested in a random effect model. No statistically significant differences were found in any of the investigated clinical parameters among the five random controlled trials (RCTs) entered into the study, indicating that there was no evidence of effectiveness. However, significant heterogeneity, a high risk of bias in three of the five included studies, and methodological shortcomings indicate that the results should be considered with caution. Future long-term, well-designed RCTs are needed to assess the scientific evidence of Er:YAG laser efficacy as an alternative treatment strategy to SRP.

Lack of adjunctive benefit of Er:YAG laser in non-surgical periodontal treatment: a randomized split-mouth clinical trial

AIM

This split-mouth, randomized, clinical trial aimed to evaluate the efficacy of erbium-doped:yttrium-aluminium-garnet (Er:YAG) laser application in non-surgical periodontal treatment.

MATERIALS AND METHODS

A total of 27 patients underwent four modalities of non-surgical therapy: supragingival debridement; scaling and root planing (SRP)+Er:YAG laser; Er:YAG laser; and SRP. Each strategy was randomly assigned and performed in one of the four quadrants. Clinical outcomes were evaluated at 3 and 6 months. Subjective benefits of patients have been evaluated by means of questionnaires.

RESULTS

Six months after therapy, Er:YAG laser showed no statistical difference in clinical attachment gain with respect to supragingival scaling [0.15 mm (95% CI -0.16; 0.46)], while SRP showed a greater attachment gain than the supragingival scaling [0.37 mm (95% CI 0.05; 0.68)]. No difference resulted between Er:YAG laser+SRP and SRP alone [0.05 mm (95% CI -0.25; 0.36)].

CONCLUSIONS

The adjunctive use of Er:YAG laser to conventional SRP did not reveal a more effective result than SRP alone. Furthermore, the sites treated with Er:YAG laser showed similar results of the sites treated with supragingival scaling.

Subjective intensity of pain during supportive periodontal treatment using a sonic scaler or an Er:YAG laser

OBJECTIVE

To assess the subjective intensities of pain during supportive periodontal treatment using a sonic scaler or an Er:YAG laser.

MATERIAL AND METHODS

Forty patients with two residual periodontal pockets following conventional periodontal therapy were treated using a sonic scaler and an Er:YAG laser in a split-mouth design. A visual analogue scale was used for pain assessment directly after each treatment procedure. Additionally, pain was recorded during the treatment of 11 patients at intervals of 0.5 s using an inter-modal intensity comparison.

RESULTS

Pain assessment during treatment showed that laser treatment (median pain score: 0.71 U, maximum: 9.94 U, minimum: 0 U) caused less pain than the sonic device (median pain score: 2.17 U, maximum: 11.26 U, minimum: 0 U) (p<0.05) with no difference in the treatment time (p>0.05). These results could be confirmed by the visual analogue scale: pain scores assessed after laser treatment (median: 1 U, maximum: 7 U, minimum: 0 U) were lower than those after sonic instrumentation (median: 3.5 U, maximum: 7.5 U, minimum: 0 U) (p<0.05).

CONCLUSIONS

Using an Er:YAG laser during supportive periodontal treatment, painful sensations can be reduced compared with sonic scaler instrumentation.

Nonsurgical mechanical treatment strategies for periodontal disease

The comparison of the efficacy of surgical and nonsurgical procedures revealed that scaling and root planing alone or in combination with flap procedures are effective methods for the treatment of chronic periodontitis. Also, the consistent message is that in treating deep pockets, open-flap debridement results in greater probing pocket depth reduction and clinical attachment gain than nonsurgical modalities. Nonsurgical modalities in shallower pockets consistently involve less post-therapy recession and are clearly recognized as being more conservative. Research is still needed on the clinical benefit of the granulation tissue removal that is a feature of periodontal surgical therapy and, to a lesser extent, occurs through indirect trauma in nonsurgical therapy.

Cavitation occurrence around ultrasonic dental scalers

Ultrasonic scalers are used in dentistry to remove calculus and other contaminants from teeth. One mechanism which may assist in the cleaning is cavitation generated in cooling water around the scaler. The vibratory motion of three designs of scaler tip in a water bath has been characterised by laser vibrometry, and compared with the spatial distribution of cavitation around the scaler tips observed using sonochemiluminescence from a luminol solution. The type of cavitation was confirmed by acoustic emission analysed by a 'Cavimeter' supplied by NPL. A node/antinode vibration pattern was observed, with the maximum displacement of each type of tip occurring at the free end. High levels of cavitation activity occurred in areas surrounding the vibration antinodes, although minimal levels were observed at the free end of the tip. There was also good correlation between vibration amplitude and sonochemiluminescence at other points along the scaler tip. 'Cavimeter' analysis correlated well with luminol observations, suggesting the presence of primarily transient cavitation.

Ultrasonic scaler oscillations and tooth-surface defects

Damage to tooth root surfaces may occur during ultrasonic cleaning with both piezoelectric and magnetostrictive ultrasonic scalers. It is unclear which mechanism causes more damage or how their mechanism of action leads to such damage. Our null hypothesis is that tooth-surface defect dimensions, resulting from instrumentation with ultrasonic scalers, are independent of whether the scaler probe is magnetostrictive or piezoelectric. Piezoelectric and magnetostrictive ultrasonic scaler probes were placed into contact against polished dentin samples (100 g/200 g). Resulting tooth surfaces were evaluated with a laser metrology system. Ultrasonic instrumentation produced an indentation directly related to the bodily movement of the probe as it made an impact on the surface. Load, generator power, and probe cross-section significantly affected probe vibration and defect depth/volume. Defect dimensions were independent of generator type. Magnetostrictive probes oscillated with greater displacement amplitudes than piezoelectric probes, but produced similar defects. This may be due to the cross-sectional shape of the probes.

Innovations in non-surgical periodontal therapy: Consensus Report of the Sixth European Workshop on Periodontology

INTRODUCTION

The remit of this working group was to update the existing knowledge base in non-surgical periodontal therapy. The published systematic reviews from the fourth EAP Workshop formed the starting point for this update and in addition specific innovations not covered in previous workshops were included.

MATERIAL AND METHODS

The literature was systematically searched and critically reviewed. Five manuscripts were produced in five specific topics identified as areas where innovative approaches have been developed in non-surgical periodontal therapy and which were deemed to be strategically important for patient care and clinical practice.

RESULTS

The results and conclusions of the review process are presented in the following papers, together with the group consensus statements, clinical implications and directions for future research: A systematic review of the effects of full mouth debridement with and without antiseptics in patients with chronic periodontitis. Advances in Power Driven Instrumentation. Laser application in non-surgical periodontal therapy - a systematic review. Antimicrobial therapy in periodontitis: the use of systemic antimicrobials against the subgingival biofilm. The cost-effectiveness of supportive periodontal-care for patients with chronic periodontitis.

Root surface defect produced by hand instruments and ultrasonic scaler with different power settings: an in vitro study

The aim of this study was to evaluate the root surface defect produced by hand curettes and ultrasonic tips with different power settings. Forty root surfaces were divided into 4 groups according the treatment: Gracey curettes, ultrasonic scaler at 10% power, ultrasonic scaler at 50% power and ultrasonic scaler at 100% power. Each specimen was instrumented with 15 strokes and the and divided in the middle to evaluate: (1) the defect depth produced by the instrumentation and (2) contact area of the instrument tips, which was analyzed by scanning electron microscopy. ANOVA and Tukey's test were used for statistical analysis (a=0.05). The results (mean ± SD) of the contact area showed significantly greater defects (p<0.05) for the hand instrumented groups (2092.9 ± 482) compared to the ultrasonic groups (606.8 ± 283.0; 858.6 ± 422.5; 1212.0 ± 366.7, respectively), independently of the power setting. The values for the defect depth on root surface showed no statistically significant difference (p<0.05) between hand instrumentation (66.1 ± 34.0) and ultrasonic scaling at 10%, 50% or 100% power settings (52.4 ± 22.1; 72.0 ± 29.9; 77.7 ± 37.7, respectively). The findings of this study demonstrate that ultrasonic instrumentation produced a similar defect depth to that of hand instrumentation, with a smaller tip contact area, independently of the power setting used for scaling.