Assessing the effect of piezoelectric ultrasonic scaler tip wear on root surface roughness under influence of various working parameters: A profilometric and atomic force microscopic study

Background

Assessing the effect of scaler tip wear on the root surface roughness using piezoelectric ultrasonic scaling device under influence of various working parameters, i.e. power setting, lateral force, and instrumentation time.

Materials and Methods

An experimental study was conducted using 160 single-rooted tooth samples divided into two groups of new (n = 80) and worn tips (n = 80). Samples were prepared to examine the root surface roughness after being instrumented by new and worn piezoelectric ultrasonic tips (8 new/8 worn) at different parameters. The erosion ratio (ER) of the new/worn tip was examined under an atomic force microscope and roughness over root surface was measured by a contact surface profilometer. One-way analysis of variance test, post hoc Tukey's test, and independent t-test were used for intragroup, pair-wise multiple comparisons and intergroup comparison of average roughness (Ra) value.

Results

A statistically significant difference was found between the ER of new and worn scaler tips (P < 0.001). Intragroup comparison between subgroups 1 and 8 showed a higher Ra value in both the groups (P < 0.005). There was a significantly higher Ra value of worn tips compared to new tips (P < 0.05). Significantly higher mean Ra value was shown when lateral force changed from 50 g to 100 g (P < 0.005).

Conclusions

Increasing value of power setting, lateral force, and instrumentation time caused more surface roughness in worn-out scaler tips compared to new scaler tips. Lateral force and instrumentation time proved to be a major factor influencing surface roughness.

The Effect of Piezoelectric Ultrasonic Scaler Tip Wear on Root Surface Roughness at Different Working Parameters: An Atomic Force Microscopic and Profilometric Study

OBJECTIVE

This study aimed to evaluate the influence of scaler tip wear and different working parameters, i.e., lateral force, power setting and tip angulation, on the roughness of root surfaces following treatment with piezoelectric ultrasonic scaling devices.

MATERIALS

Twenty piezoelectric ultrasonic scaler inserts (10 worn/10 new) were selected to examine the erosion ratio (ER) under atomic force microscopy (AFM). A total of 160 root samples were prepared and instrumented by new (n = 80) and worn inserts (n = 80) at different working parameters (tip angulation, power setting, lateral force). Roughness change (Rc) on root surfaces after instrumentation was examined by a contact profilometer.

RESULTS

Statistically significant differences were found between the mean ERs of new and worn tips (p < 0.0001). The various combinations of the assessed working parameters showed synergistic effects resulting in a wide range of root surface roughness. The present study found the higher Rc in the group with a 45° angulation, (P10) high power setting and 1.0 N lateral force (subgroup 8) when compared to other groups. Among the groups, the worn scaler tips subgroup 8 showed a higher Rc (5.692 ± 0.81) when compared to new scaler tips subgroup 8 (4.798 ± 0.51; p < 0.001).

CONCLUSION

The findings of the present study highlighted that scaler tip wear strongly influences the root surface roughness when used at higher tip angulation, lateral force and power settings. Hence, ultrasonic scaler tip wear should be periodically evaluated and should be considered as much as the other working parameters.