The effect of the angle of instrumentation of the Piezoelectric Ultrasonic Scaler on root surfaces

Effect of Two Different Intraoral Polishing Systems on Surface Roughness, Color Stability, and Bacterial Accumulation of Zirconia-Reinforced Lithium Silicate Ceramic

OBJECTIVE

 The aim of this study was to investigate the effects of two intraoral polishing methods on zirconia-reinforced lithium silicate ceramic after ultrasonic scaling.

MATERIALS AND METHODS

 Thirty disc-shaped samples of zirconia-reinforced lithium silicate were constructed. Freshly extracted bovine teeth were collected and cleaned then the discs were cemented into a cavity prepared onto their labial surface. The samples were divided into three groups (10 samples per group); S: Scaling only, SE: Scaling followed by polishing using Eve Diapro lithium disilicate polishers, SD: Scaling followed by polishing using Diatech ShapeGuard ceramic polishing plus kit. The surface roughness was evaluated after scaling and polishing the samples. For color stability, the samples were stored for 12 days at 37°C in an incubator to simulate 1-year consumption of coffee. L*a*b* color parameters were assessed using VITA Easyshade Advance 4.0 before and after the staining procedure and the color difference was measured. Finally, bacterial accumulation was evaluated by incubating the samples with a suspension of Streptococcus mutans ( S. mutans), after that the S. mutans colonies were counted to obtain the values of colony-forming units (CFU). The final overall roughness, change in color and bacterial count were compared between all groups using one-way ANOVA and Tukey's post-hoc analysis. The Pearson correlation coefficient was used to determine the correlation between continuous variables. The cutoff for significance was chosen at p ≤ 0.05.

RESULTS

 Scaling induced surface roughness of the zirconia-reinforced lithium silicate ceramic was significantly decreased after using both intraoral polishing systems and this was accompanied by a significant decrease in color change and bacterial count.

CONCLUSION

 Intraoral polishing techniques can reduce the roughness of the surface of zirconia reinforced lithium silicate restorations induced due to scaling and subsequently reduce the stainability and bacterial accumulation.

Effects of a new magnetostrictive ultrasonic scaler and a traditional piezoelectric ultrasonic scaler on root surfaces and patient complaints

Tooth wear and pain are the primary concerns of patients undergoing periodontal scaling. The aims of this study were to compare the effects of a new magnetostrictive ultrasonic scaler and a traditional piezoelectric ultrasonic scaler on tooth surface roughness and calculus removal and to determine their impacts on patient discomfort during supragingival cleaning. This article had two parts: an in vitro study and a clinical study. In the in vitro study, thirty teeth with subgingival calculus were randomly assigned to two scaling treatment groups: magnetostrictive scalers (n = 15) and piezoelectric scalers (n = 15). Surface roughness measurements were taken at baseline and after scaling, and the root samples were visualised by SEM after scaling. Additionally, a single-centre randomised split-mouth clinical trial was conducted. Eighty-five participants diagnosed with chronic gingivitis or periodontitis were randomly assigned to receive supragingival scaling. The magnetostrictive scaler was used in half of the mouths (n = 85), and the piezoelectric scaler was used in the other half of the mouths (n = 85). Data on pain, noise, and vibration were collected using a VAS questionnaire, and the operating time was recorded. In both in vitro and clinical studies, magnetostrictive scalers were reported to be more effective than piezoelectric scalers in removing dental deposits (P < 0.05). Additionally, the root surface after scaling with the magnetostrictive scaler was smoother than that after scaling with the piezoelectric scaler in the in vitro study (P = 0.02). SEM examination also revealed that fewer dental materials were lost after instrumentation with the magnetostrictive scaler than after instrumentation with the piezoelectric scaler. Piezoelectric scalers caused less discomfort to patients in terms of pain, noise, and vibration than magnetostrictive scalers (P < 0.05). According to this clinical study, the magnetostrictive scaler caused more discomfort during supragingival scaling than the piezoelectric scaler. Moreover, the magnetostrictive scaler was also more efficient and produced a smoother root surface with less material loss after scaling than the piezoelectric scaler, as demonstrated in the in vitro study.

Complications and treatment errors in nonsurgical periodontal therapy

Nonsurgical periodontal therapy can be subject to iatrogenesis, which includes all the complications directly or indirectly related to a treatment. These complications include both operator-dependent harms and errors and the consequences and adverse effects of the therapeutic procedures. The complications arising following nonsurgical periodontal treatment can be categorized as intraoperative and postoperative and can affect both soft and hard tissues at an intra-oral and extraoral level. Soft-tissues damage or damage to teeth and restorations can occur while performing the procedure. In the majority of cases, the risk of bleeding associated with nonsurgical therapy is reported to be low and easily controlled by means of local hemostatic measures, even in medicated subjects. Cervicofacial subcutaneous emphysema is not a frequent extraoral intraoperative complication, occurring during the use of air polishing. Moreover, side effects such as pain, fever, and dentine hypersensitivity are frequently reported as a consequence of nonsurgical periodontal therapy and can have a major impact on a patient's perception of the treatment provided. The level of intraoperative pain could be influenced by the types of instruments employed, the characteristics of tips, and the individual level of tolerance of the patient. Unexpected damage to teeth or restorations can also occur as a consequence of procedural errors.

Effect of Different Scaling Methods on the Surface Topography of Different CAD/CAM Ceramic Compositions

This study evaluated the effect of ultrasonic and manual scaling using different scaler materials on the surface topography of computer-aided designing and computer-aided manufacturing (CAD/CAM) ceramic compositions. After scaling with manual and ultrasonic scalers, the surface properties of four classes of CAD/CAM ceramic discs: lithium disilicate (IPE), leucite-reinforced (IPS), advanced lithium disilicate (CT), and zirconia-reinforced lithium silicate (CD) of 1.5 mm thickness were evaluated. Surface roughness was measured before and after treatment, and scanning electron microscopy was used to evaluate the surface topography following the performed scaling procedures. Two-way ANOVA was conducted to assess the association of the ceramic material and scaling method with the surface roughness. There was a significant difference in the surface roughness between the ceramic materials subjected to different scaling methods (p < 0.001). Post-hoc analyses revealed significant differences between all groups except for IPE and IPS where no significant differences were detected between them. CD showed the highest surface roughness values, while CT showed the lowest surface roughness values for the control specimens and after exposure to different scaling methods. Moreover, the specimens subjected to ultrasonic scaling displayed the highest roughness values, while the least surface roughness was noted with the plastic scaling method.

Comparison of Root Surface Wear and Roughness Resulted from Different Ultrasonic Scalers and Polishing Devices Applied on Human Teeth: An In-Vitro Study

The aim of the present study was to compare the root surface wear and roughness, resulted from the professional dental hygiene instruments, including ultrasonic dental scalers, rubber prophy cups, and nylon bristle brushes, on the extracted human mandibular incisor teeth. Teeth (n = 80) were randomly assigned into eight groups according to the applied scaler type (Ma = Magnetostrictive, Pi = Piezoelectric), degree of power (M = Medium, F = Full), and angulation (0° and 45°). In the second stage, the specimens (n = 40) were further divided into two groups according to the applied polishing device (nylon bristle brush or rubber prophy cup). Laser scanner and contact profilometer devices were used for the surface analysis. Both ultrasonic instruments tested in our study produced rougher surfaces when full power was used at a 0° angle (p < 0.01). The highest wear (0.82 ± 0.07 mm3) and roughness values (0.30 ± 0.01 µm) were detected in the PiF0 group. Polishing performed with a rubber prophy cup resulted in almost twice the wear as well as a smoother surface when compared to polishing performed with a nylon bristle brush (p < 0.001). Variations in the application parameters of ultrasonic scalers and the type of polishing instrument might lead to significantly different root-surface characteristics.

Surface changes of metal alloys and high-strength ceramics after ultrasonic scaling and intraoral polishing

PURPOSE

MATERIALS AND METHODS

RESULTS

CONCLUSION