Do ultrasonic instrumentation and air polishing procedures adversely affect dental restorations?

Abstract

A commentary on: Esati J, Amran T, Weiger R, Alsulaimani L, Blatz M B, Eggmann F. Adverse effects of ultrasonic instrumentation and air polishing on dental restorations: a systematic review of laboratory studies. J Esthet Restor Dent 2025; https://doi.org/10.1111/jerd.13428 .

Objective: A systematic review of the literature was conducted, assessing the potential for adverse effects on surface roughness and marginal integrity with use of ultrasonic instrumentation and air polishing on variety of dental restorations. With the aim to guide clinical practice to aid mitigation of adverse effects.

Data sources: Five databases: Cochrane Library, OpenGrey through DANS, PubMed, Scopus, and Web of Science, and supplemental manual searches were used to identify relevant literature. The review adhered to the PRISMA guidelines.

Study selection: Publications were included between 1978 and 2022.

Population: dental restorations or restorative biomaterials in vitro.

Intervention: ultrasonic instrumentation and/or air polishing. Comparison: no debridement procedure or paste polishing.

Outcome: surface roughness and/or marginal quality. Forty-two laboratory studies were included in the final analysis. The studies evaluated data to answer the following research question: In specimens made of or featuring dental restorations or restorative biomaterials, how does the use of ultrasonic instrumentation and/or air polishing, compared with no debridement procedure or paste polishing, affect the surface roughness and/or marginal quality?

Data extraction and synthesis: Data extracted included: author(s) and year, laboratory studies, biomaterials evaluated, specimen quantity, specimen geometry, grouping methodology, types of ultrasonic and/or air polishing devices used, air polishing powders, device operational settings, application type and duration of ultrasonic and/or air polishing, assessments of surface roughness and marginal quality, and the observed effects on both surface roughness and marginal quality. Biomaterial assessed included: porcelain fused to metal (PFM), zirconia (ZrO₂), lithium disilicate (LDS), polymer-infiltrated ceramic network material (PICN), fine-structure felspathic ceramic (FSFC), gold alloy, amalgam, resin-modified glass ionomer cements (RMGIC), conventional and flowable resin-based composite (RBC), and silorane-based RBCs restorations. Studies measured surface roughness via contact profilometry, scanning electron microscopy, and atomic force microscopy. Ra was used as a parameter for surface roughness. Stereomicroscopy and confocal laser microscopy were used to assess marginal quality. Risk of bias was assessed using the RoBDEMAT tool.

Results: Ultrasonic instrumentation and air polishing both negatively impacted surface roughness. Air polishing with sodium bicarbonate and calcium carbonate powders had a significantly greater effect on surface roughness, compared with erythritol and glycine powders. The surface roughness for RBCs and RMGICs were the most affected by ultrasonic instrumentation. In comparison, ZrO₂ and LDS restorations were found to have the highest level of resistance compared to other restorations. Three studies observed that an increase in surface roughness could be mitigated using rubber cups and polishing paste after instrumentation. Ultrasonic instrumentation and air polishing methods both led to an adverse marginal quality outcome. Crowns with a narrow ceramic shoulder margin (0.7 mm) were particularly susceptible. RMGIC and amalgam restorations had a greater adverse impact on the marginal quality compared with RBC restorations.

Conclusions: It is advised to use air polishing with less abrasive powders, including erythritol and glycine, to mitigate surface damage and changes at the marginal interface. Another important clinical consideration is the type of restorative material. High strength ceramic restorations, such as LDS and ZrO₂, are much more resistant to surface roughening compared with all other materials.