Influence of airborne particle abrasion on dentin bonding effectiveness of a 2-step universal adhesive

OBJECTIVE

To determine the effect of airborne particle abrasion (APA) on micro-tensile bond strength (µTBS) to dentin using different air-abrasion/polishing powders.

METHODS

The bonding effectiveness of G2 Bond Universal (G2B), used in etch-and-rinse (E&R) and self-etch mode (SE), was tested on bur-cut dentin and dentin air abraded/polished using six different powders (aluminum oxide 29 µm (AO29) and 53 µm (AO53), aluminum trihydroxide (AT), sodium bicarbonate (SB), sodium bicarbonate soft (SBsoft) and bioactive glass (BG); Velopex). Adhesive-composite resin specimens were immersed in distilled water at 37 °C for one week and cut into microspecimens. Half of the specimens were subjected to 50,000 thermocycles (aged). Immediate and aged μTBS to dentin were measured. Statistical analysis was performed using linear mixed-effects (LME) modeling (p < 0.05).

RESULTS

Comparing the aged bond strengths to air-abraded/polished dentin with bur-cut dentin, pretreatment with SB and SBsoft in combination with G2B used in E&R mode, and BG air polishing in combination with both application modes (E&R, SE), resulted in a significantly higher bond strength. Dentin bond strength was only significantly lower when air abraded with AO29 and using G2B in SE mode. Aging did not significantly influence bond strength for both application modes (E&R, SE), except for AO29 and AT-treated dentin, where bond strengths decrea sed significantly using G2B in SE mode. In general, G2B reached significantly higher bond strengths on air-abraded/polished dentin in E&R mode than in SE mode.

CONCLUSION

Air-abrasion/polishing did not impair dentin bond strength using G2B, except when dentin was air abraded with AO29 and using G2B in SE mode. Air polishing positively influenced the bond strength to dentin in specific groups.

CLINICAL SIGNIFICANCE

APA is safe concerning bonding to dentin. The E&R application mode is preferred using G2B as adhesive on air-abraded/polished dentin. Air polishing with BG positively influenced dentin bond strength for both application methods.

Long-term effect of simulated five years professional mechanical biofilm removal on the luting gap of ceramic restorations

BACKGROUND

Achieving sufficient professional mechanical biofilm removal (PMPR) can be challenging in supportive periodontal therapy (SPT), particularly in patients with prosthetic restorations. This experimental study aimed to simulate five years of SPT with periodic PMPR near the luting gap of ceramic restorations using a rubber cup with polishing paste (RCP), air polishing with two different low-abrasive powders (LAPA-1: glycine powder, LAPA-2: erythritol powder), and non-professional mechanical cleaning (control group) to measure the extent of volume loss in the luting gap after baseline (∆V = Vbaseline-V1-5; in µm3).

METHODS

Two operators randomly performed PMPR ten times for thirty seconds on one of four sides of 30 crown replicas fixed with glass-ionomer cement (CGIZ: n = 15) or adhesive bonding (CAB: n = 15). The replicas were separated in a template during PMPR, and afterward, cleaned for five seconds per side with a sonic brush under flowing water. The artificial aging process between two PMPRs simulated a 5-year SPT with two PMPRs per year. Profilometric measurements were performed at baseline and after each second PMPR to obtain the mean change of ∆V. The statistical evaluation of the data was carried out using nonparametric tests with Bonferroni correction applied for multiple tests.

RESULTS

Ninety-six out of 120 sides could be included in the analysis. PMPR methods showed a loss of substance in the luting gap with a ∆V (mean(standard deviation)) of -4.35 × 106(4.8 × 106)µm3 versus 8.79 × 104(1.05 × 106)µm3 for control at V5 (p ≤ 0.001). No significant differences of ∆V1-5 values could be identified in the control (p > 0.05), whereat all PMPRs showed a significant increasing loss of substance per simulated year (p ≤ 0.001). Intergroup comparison identified LAPA-1 as having the highest significant loss of substance determined on CAB (∆V: -1.05 × 107 (7,2 × 106) µm3), followed by LAPA-2 on CAB (∆V: -6.29 × 106 (4,24 × 106) µm3), LAPA-1 on CGIZ (∆V: -4.15 × 106 (3,25 × 106) µm3), LAPA-2 on CGIZ (∆V: -3.0 × 106 (2,23 × 106) µm3), RCP on CAB (∆V: -1.86 × 106 (2,23 × 106) µm3) and CGIZ (∆V: -1.2 × 106 (1,31 × 106) µm3; p ≤ 0.001)).

CONCLUSIONS

Within study limitations, all PMPRs caused a significantly higher loss of substance in the luting gap versus control without professional intervention, with the highest values in the CAB group for LAPA-1, LAPA-2 and RCP. Similar findings were observed for CGIZ, although the loss values were lower.

Influence of dental prophylaxis procedures on the tooth veneer interface in resin-based composite and polymer-infiltrated ceramic veneer restorations: an in vitro study

OBJECTIVES

The aim of this study was to investigate the influence of dental prophylaxis cleaning procedures and artificial aging on veneers in human teeth. The external marginal and internal tooth veneer as well as the restoration surfaces were examined.

MATERIAL AND METHODS

Thirty-two extracted premolars were restored with resin-based composite (RBC) and polymer-infiltrated ceramic network (PICN) veneers. Artificial aging by alternating thermocycling and subsequent prophylaxis procedure (glycine-based powder air polishing or ultrasonic scaling) was conducted for five consecutive cycles. The external marginal interface was examined by height profile measurements and the internal interface was investigated using micro X-ray computed tomography. In addition, the surface texture of the veneer surface was analyzed using confocal laser scanning microscopy.

RESULTS

The application of both prophylaxis procedures resulted in a deepening of the marginal interface (10 µm ± 8 µm) for materials. Furthermore, the internal interface of PICN restorations showed marginal gaps after both treatments and artificial aging (16 µm ± 3 µm). In contrast to the RBC specimens, a significant increase in surface roughness was identified for PICN veneers after ultrasonic scaling.

CONCLUSIONS

The marginal and internal interface regions in veneers fabricated from PICN and RBC were affected by prophylaxis procedures. Furthermore, it may result in increased veneer surface roughness, especially in PICN and after ultrasonic scaling, which might affect bioadhesion and longevity.

CLINICAL RELEVANCE

After dental prophylaxis procedures, examination of the marginal and the internal interface as well as the veneer surface provides a precise insight into damage mechanisms and offers an assessment of longevity.

Efficacy of air polishing in comparison with hand instruments and/or power-driven instruments in supportive periodontal therapy and implant maintenance: a systematic review and meta-analysis

BACKGROUND

Supportive periodontal therapy (SPT) is the key for a stable periodontal health following active treatment. Likewise, implant maintenance is crucial following implant placement. This systematic review aimed to assess clinical outcomes, patients' perception, and cost-effectiveness of repeated periodontal therapy with air polishing devices (APDs) in comparison with hand instruments and/or power-driven instruments (conventional interventions) in SPT and implant maintenance.

METHODS

Electronic search for randomised controlled clinical trials with minimum 6 months follow-up for SPT and implant maintenance programme was conducted for data published from 01 January 2000 to 30 April 2020 using multiple databases and hand searching. Risk of bias was assessed using the Revised Cochrane Risk-of-Bias tool (RoB 2).

RESULTS

A total of 823 articles were screened. 4 SPT and 2 implant maintenance studies were eligible for inclusion. For SPT, repeated APDs interventions revealed no statistically significant difference when compared to the conventional interventions (weighted mean difference [WMD] 0.11 mm, p = 0.08). Likewise, no statistical difference was noted in terms of percentage of bleeding on probing (BOP) and clinical attachment level (CAL) gain. APDs were associated with lower pain score (based on Visual Analogue Scale) and higher patient acceptance in SPT studies. For implant maintenance, APDs resulted in reduction in PPD and percentage of BOP. However, CAL gain was comparable between the two groups. In terms of patient reported outcomes, no implant maintenance studies recorded any forms of patient reported outcomes. In addition, no studies reported on economic evaluation of APDs in both SPT and implant maintenance.

CONCLUSION

Within the limitations of this systematic review and meta-analysis, repeated subgingival debridement using APDs in SPT resulted in similar clinical outcomes but better patients' comfort when compared to the conventional interventions. For implant maintenance, there is limited evidence to show that repeated application of APDs leads to improved clinical outcomes when compared to conventional treatments.

Efficacy evaluation of rubber cup and air polishing techniques using glycine in plaque and stain removal - A clinical trial

Background:

Researchers have proved Glycine to be safe, less abrasive, sweet and comfortable for patients. It is beneficial in removing plaque as well as stains. The present study aims to compare the plaque and extrinsic stain removal efficacy of the air-polishing device and rubber cup prophylaxis technique along with a comparative evaluation of the gingival trauma caused by both the techniques.

Method:

This split-mouth randomized clinical trial was conducted on a total of 60 subjects in half of whom, left side was assigned to Glycine powder air polishing and the right side to rubber cup prophylaxis with (Glycine powder) and vice versa in the other half. All the subjects had their calculus removed one month prior to the intervention. Plaque index, Stain index and Trauma index were recorded and statistical analysis was done.

Results:

Both the techniques (RCP and AP) demonstrated a significant reduction in plaque and stains within their respective groups, but revealed non-significant differences between the study groups. Gingival trauma was found to be significantly higher in case of AP group. Rubber cup technique was preferred over air polishing by the subjects.

Conclusion

The data indicates that both the techniques were equally beneficial for plaque and stain removal, but rubber cup polishing technique has an advantage over the air polishing technique.

Evaluation of air polishing with a sterile powder and mechanical debridement during regenerative surgical periimplantitis treatment: a study in dogs

Objectives

To evaluate the effectiveness of mechanical debridement and/or air polishing on the healing of ligature-induced buccal periimplantitis dehiscence defects in dogs.

Material and methods

Forty-eight implants were placed in the mandibles of twelve beagle dogs, and periimplantitis was induced for 2 months using ligatures. The resulting buccal dehiscence-type defects were surgically cleaned and augmented (xenogenic filler and resorbable membrane) according to one of the following treatments: (1) Cleaning with carbon curette (debridement - D) and guided bone regeneration (GBR/G): DG, (2) air polishing cleaning (A) and GBR: AG, (3) a combination of D/A/G: DAG, and (4) D/A without GBR: DA. After 2 months, histomorphometric and inflammatory evaluations were conducted.

Results

The median bone gain after therapy ranged between 1.2 mm (DG) and 2.7 mm (AG). Relative bone gain was between 39% (DG) and 59% (AG). The lowest inflammation scores were obtained in DA without GBR (5.84), whereas significantly higher values between 8.2 and 9.4 were found in the groups with augmentation. At lingual sites without defects, scores ranged from 4.1 to 5.9. According to ISO, differences above 2.9 were considered representative for irritative properties.

Conclusions

All treatments resulted in partial regeneration of the defects. No treatment group showed a significantly (p < 0.05) better outcome. However, pretreatment with air polishing showed a tendency for less inflammation. Noteworthy, inflammation assessment showed an overall irritative potential after GBR in the evaluated early healing phase.

Clinical relevance

Periimplantitis treatment still represents a big issue in daily practice and requires additional preclinical research in order to improve treatment concepts.

Air polishing with erythritol powder - In vitro effects on dentin loss

Context:

Low-abrasive polishing powders such as glycine (GLY) or erythritol (ERY) are used for subgingival air polishing. GLY was reported to possibly affect the dentin surface, while this is unclear for ERY.

Aims:

This in vitro study aimed to evaluate the substance loss from the dentin surface by air polishing with ERY at different settings for pressure (PR), distance (DI), and angulation of the spray jet to the surface (AJ).

Materials and Methods:

The in vitro testing was performed on smooth human root dentin surfaces. In 18 groups with 10 specimens each, ERY was applied with constant water supply for 5 s without moving the handpiece at the following settings: PR minimum (min), medium (med), and maximum (max); DI at 1, 3, and 5 mm; and 45° or 90° AJ. The substance loss was measured as defect depth (DD) using three-dimensional (3D)-laser profilometry. ANOVA with Bonferroni correction and α = 0.05 were used for statistical analysis.

Results:

The DD was statistically significantly higher at a DI of 1 mm compared to a DI of 5 mm for the respective groups of the same PR and AJ (P < 0.05). For DI 1 mm, max PR, and AJ 90°, the maximum loss of substance amounted DD of 117 ± 43 μm. The minimal loss of substance occurred at minimal PR, 45° AJ, and a DI of 5 mm (15 μm × 20 μm). DD related directly with the parameters PR and AJ and inversely with DI. The highest influence on DD was proven for DI.

Conclusions:

Slight loss of dentin might occur during air polishing with ERY depending on DI, PR and AJ. The setting influences the amount of dentin loss.

A randomized, controlled, clinical pilot study

Aim

To evaluate the outcomes following surgical periodontal treatment and root surface decontamination by means of air polishing using an erythritol powder or conventional mechanical root debridement.

Material and methods

Thirty systemically healthy patients (44.38 ± 8.2 years old, 11 smokers, 19 women) diagnosed with periodontitis stages III–IV were included. Each patient, with one single-rooted tooth, with one probing pocket depth (PD) ≥ 6 mm associated with horizontal bone loss, was treated by means of simplified papilla preservation flap (SPPF) and randomized to either test treatment (careful removal of the calculus with the tip of a blade, air polishing of the root surfaces with erythritol) or to the control group (scaling and root planing with hand curettes, ultrasonic instruments). PD, clinical attachment (CAL), bone sounding (BS), and radiographic bone level (BL) were evaluated at baseline and 12 months postsurgically.

Results

Twenty-seven patients completed the 12-month follow-up (test: n = 14, control: n = 13). In both groups, statistically significant improvements were obtained (p < 0.05, mean CAL gain/PD reduction: test, 2.50 ± 1.60 mm/3.00 ± 0.96 mm; control, 2.85 ± 1.21 mm/3.38 ± 1.12 mm). No statistically significant differences were observed between the groups for any of the investigated parameters (p < 0.05).

Conclusion

Within their limits, the present results indicate that the use of air polishing with an erythritol powder during periodontal surgery may represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus.

Clinical relevance

The use of air polishing with an erythritol powder during periodontal surgery appears to represent a valuable minimally invasive adjunct following calculus removal by means of hand and ultrasonic instruments or a valuable alternative to these, for root surfaces without calculus.

Clinical comparison of the stain removal efficacy of two air polishing powders

Objectives:

Air polishing with sodium bicarbonate powders with a grain size of 40 μm is recommended for patient comfort. However, the efficacy of small grain size on stain removal has not been adequately studied. This study aimed to compare the stain removal efficacy of sodium bicarbonate powders with grain sizes of 65 and 40 μm and to evaluate patient acceptance and operator opinion after using both air polishing powders.

Materials and Methods:

A double-blind, randomized, split-mouth study was conducted with 35 participants with moderate to heavy dental staining on both sides of the upper teeth. Removal of dental stains on the index teeth was performed using sodium bicarbonate powders with a grain size of either 65 or 40 μm. The time taken to completely remove all dental stains was recorded. After treatment, a questionnaire was used to evaluate patient acceptance and the operator's opinion.

Results:

The average time for the removal of all stains by powder was 4.5 ± 3.6 min with a grain size of 65 μm and 4.4 ± 3.8 min with a grain size of 40 μm. The difference in the average time between the two groups was not significant (P = 0.461). The operator's opinions of the two powders were identical, and patient acceptance did not differ significantly between the two types of powders.

Conclusions:

The 40 μm sodium bicarbonate powder removed dental stains as efficiently as the 65-μm powder. Powder handling and patient acceptance were comparable between grain sizes of 65 and 40 μm.

The effect of supragingival glycine air polishing on periodontitis during maintenance therapy: a randomized controlled trial

Background

Glycine air polishing has been proved to be safe, comfortable and time-saving. Whether it could substitute ultrasonic scaling to remove dental plaque biofilm during periodontal maintenance remains unclear. The purposes of this study were to evaluate the effect of supragingival glycine air polishing (SGAP) on the subgingival periodontal pathogens during maintenance therapy and to check the association of periodontal pathogens and clinical parameters.

Methods

Twenty-three chronic periodontitis patients during their maintenance therapy were enrolled in the 12-week study. According to randomized split-mouth design, the test side was treated with SGAP (65 μm), while the control side was treated with supragingival ultrasonic scaling and polishing (SUSP) with rubber cup. Clinical examination including plaque index (PLI), probing depth (PD), bleeding index (BI) were performed at baseline and 12 weeks post-treatment. Sampling of the subgingival plaque at each investigational site (mesiobuccal site of the mandibular first molar) was performed at baseline and 2, 4, 8, 12 weeks after maintenance treatment. Four periodontal pathogens including Porphyromonas gingivalis, Tannerella forsythia, Treponema denticola and Fusobacterium nucleatum were detected by 16S rDNA polymerase chain reaction.

Results

Clinical status generally improved after treatment in both groups. PLI in both groups, PD in SGAP group and bleeding on probing (%) in SUSP group significantly decreased after treatment (p < 0.05). There was no significant difference of clinical parameters between two groups before and after treatment. The detection rates of P. gingivalis, T. denticola in both groups, T. forsythia in SUSP group and F. nucleatum in SGAP group decreased after maintenance treatment in both groups, although no significant difference was found, and it rebound to baseline level at 12 weeks after maintenance treatment. There was no significant difference between SGAP group and SUSP group at any time point. T. denticola-positive sites had significantly greater BI than T. denticola-negative sites (p < 0.05).

Discussion

Supragingival glycine air polishing had a reliable effect in removing subgingival dental plaque biofilm during maintenance period, and three months may be a proper maintenance interval for pockets not more than 5 mm.

Comparative evaluation of gingival trauma by Prophy-Jet and rubber-cup polishing techniques using aluminium trihydroxide

Objective:

The aim of the present study was to compare the gingival trauma with Prophy-Jet and rubber-cup polishing techniques using aluminium trihydroxide as polishing agent.

Materials and Methods:

15 subjects suffering from gingivitis were enrolled in a randomized controlled split mouth experimental investigation. After scaling, Prophy-Jet and rubber-cup polishing techniques were applied on either side of the mouth using aluminium trihydroxide as polishing agent and the gingival trauma was assessed immediately after, 7 days and 21 days posttreatment using trauma index (TI).

Results:

Statistically significant difference was observed in the mean TI scores of gingiva immediately after polishing with the two techniques, with the mean score of 0.25 ± 0.12 after rubber-cup and 0.40 ± 0.11 after prophy- jet polishing technique.

Conclusion:

Within the limitations of the study, it can be concluded that inspite of higher gingival trauma immediately after air polishing using aluminium trihydroxide agent, there was no lasting difference in gingival trauma between rubber-cup and air-polishing techniques at 7 and 21 days posttreatment.