Influence of the power level of an ultra-sonic system on dental cavity preparation

Sonic and ultrasonic oscillating devices for the management of pain and dental fear in children or adolescents that require caries removal: a systematic review

OBJECTIVES

To evaluate the effectiveness and degree of acceptance by children and adolescents of the use of oscillating tips compared with rotating drills.

DESIGN

Systematic review.

DATA SOURCES

PubMed, the Cochrane Central Register of Controlled Trials (CENTRAL), the Cochrane Library and Web of Science (October 2017).

ELIGIBILITY CRITERIA

Controlled randomised or non-randomised trials that evaluated sonic and ultrasonic oscillating devices versus rotating drill.

DATA EXTRACTION

Eligible studies were selected and data extracted independently by two reviewers. Risk of bias was assessed using the Cochrane Method.

RESULTS

Two controlled clinical trials comprising 123 children aged 2-12 years old were identified. Both trials were at high risk of selection bias and unclear risk of detection bias. In one trial, pain due to the use of oscillating drill resulted lower than employing rotating drill (Verbal Hochman Scale: RR 0.64 (95% CI 0.41 to 1.00); Visual Facial Expression Scale: RR 0.64 (95% CI 0.44 to 0.94)). In another study, compared with traditional drill ultrasonic tip was associated with a lower level of patient's discomfort (RR 0.40 (95% CI 0.20 to 0.79)) but not with dental anxiety (RR 1.29 (95% CI 0.97 to 1.71)). The effectiveness of the removal of caries as well as fillings durability were only considered in one study, but no statistically significant differences were found between the two interventions.

CONCLUSIONS

The evidence based on two low-quality studies was insufficient to conclude that the use of oscillating tips for the management of pain and dental fear in children or adolescents compared with rotating drills was more effective.

Evidence provided for the use of oscillating instruments in restorative dentistry: A systematic review

Oscillating diamond instruments are considered gentle sources for the removal of demineralized tooth hard tissues and the preparation of cavity angles and margins needed in minimally invasive dentistry. However, there is a question if literature provides enough evidence for their efficacy in restorative dentistry procedures. A literature search until May 2016 was conducted, using PubMed, Scopus, and The Cochrane Central Register of Controlled Trials databases. The quality of the studies was assessed using the recommendation of the Oxford Centre for Evidence-based Medicine. Fifty-five studies were finally included in the study. Of which, 78.2% of them were laboratory studies and only 21.8% were clinical studies. The strength of recommendation was 5 for most of them and D their grade of evidence. Bond strength of adhesives on surfaces prepared with these instruments, effective caries removal and cutting characteristics of the oscillating instruments were the main targets of the studies. Conventional diamond, steel, and chemical vapor deposition diamond tips and systems based on abrasive slurry were the oscillating tips, used in different studies. The strength of recommendation and grade of evidence of the studies were low. Although these devices seem to be useful for many clinical situations, there is a need for more well-structured evidence-based studies with more widely accepted procedures and common devices, to have more meaningful results and conclusions of higher strength.

A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study

Background

Caries excavation is a noninvasive technique of caries removal with maximum preservation of healthy tooth structure.

Aim

To compare the efficacy of three different caries excavation techniques in reducing the count of cariogenic flora.

Materials and methods

Sixty healthy primary molars were selected from 26 healthy children with occlusal carious lesions without pulpal involvement and divided into three groups in which caries excavation was done with the help of (1) carbide bur; (2) polymer bur using slow-speed handpiece; and (3) ultrasonic tip with ultrasonic machine. Samples were collected before and after caries excavation for microbiological analysis with the help of sterile sharp spoon excavator. Samples were inoculated on blood agar plate and incubated at 37°C for 48 hours. After bacterial cultivation, the bacterial count of Streptococcus mutans was obtained.

Statistical analysis

All statistical analysis was performed using SPSS 13 statistical software version. Kruskal-Wallis analysis of variance, Wilcoxon matched pairs test, and Z test were performed to reveal the statistical significance.

Results

The decrease in bacterial count of S. mutans before and after caries excavation was significant (p < 0.001) in all the three groups.

Conclusion

Carbide bur showed most efficient reduction in cariogenic flora, while ultrasonic tip showed almost comparable results, while polymer bur showed least reduction in cariogenic flora after caries excavation.

How to cite this article

Hassan AF, Yadav G, Tripathi AM, Mehrotra M, Saha S, Garg N. A Comparative Evaluation of the Efficacy of Different Caries Excavation Techniques in reducing the Cariogenic Flora: An in vivo Study. Int J Clin Pediatr Dent 2016;9(3):214-217.

Free radical formation from sonolysis of water in the presence of different gases

In the present study by applying electron spin resonance-spin trapping method, when a high frequency (1650 kHz) ultrasound was irradiated to water dissolved with different gas molecules (O₂, N₂, Ar, Ne, He, and H₂) at 25°C of water bulk temperature, free radical generation pattern differed dependently on the dissolved gas molecules. Only ^•OH was detected in the O₂-dissolved water sample, and the amount of the radical was much greater than that determined in any of other gas-dissolved water samples. One of the possible reasons to explain why the ^•H radical was not detected in the O₂-dissolved water is that the ^•H reacts with O₂ to form ^•OOH. However, no electron spin resonance signals related to the adduct of not only 5,5-dimethyl-1-pyrroline-N-oxide but 5-(2,2-Dimethyl-1,3-propoxy cyclophosphoryl)-5-methyl-1-pyrroline N-oxide and ^•OOH were observed. In the H₂-dissolved water, only ^•H was detected, suggesting that H₂ reduces or neutralizes ^•OH. In the N₂-disolved water, both ^•OH and ^•H were detected at comparable level. In the water samples dissolved with rare gases (Ar, Ne, and He), the amount of ^•H was almost double as compared with that of ^•OH, and both ^•OH and ^•H yields increased in the order Ar > Ne > He.