hygiene the international C.E. magazine of dental hygiene

08 I I C.E. article_ air polishing staining on root surfaces, specifically on areas of recession and at the cementoenamel junction. Re- moving these stains with a curet has been shown to reduce root structure. However, when stain removal is for esthetic reasons, the air-powder polisher is preferable to the curet. The air-powder polisher re- moveslessrootstructurethanthecuretinsimulated three-month recalls for three years. The stain was also removed more than three times faster with the air-powder polisher.5 Using the air-powder polisher also creates less discomfort for patients who have dentinal hyper- sensitivity because the sodium bicarbonate particles embed in the dentinal tubules, lessening dentinal hypersensitivity discomfort almost immediately. In vitro, research has shown that there is little or no disruptionofenamel,cementumanddentinsurfaces with air-powder polishing. Otherresearchhasshownthatair-powderpolish- ing can render cementum surfaces more uniformly smooth, compared with traditional polishing or the use of curets.5 The air-powder polisher can remove subgingival bacteriathroughtheVenturieffect.Thisoccurswhen theair/water/powdersprayisdirectedata90-degree angle to the interproximal spaces so that a vacuum is created that extracts tissue fluids, including sub- gingival bacteria from the subgingival space. The air-powder polisher has been used for debridement of Class V abraded areas before placement of glass ionomer cements. When compared with cleaning the area with a rubber-cup polisher, the air-powder polished tooth had less microleakage around the enamel-cement interface. Similar results were noted when using the air-powderpolisherbeforesealantapplication.Itwas reported to be superior to rubber-cup polishing in preparing enamel for etching and sealants. Deeper resin penetration into enamel and in- creased sealant bond strength was also reported in comparison with traditional polishing with pumice and water. In addition, clinicians prefer using the air-powder polisher on orthodontic patients, and researchhasshownthatitdoesnotaffectthebracket adhesive system. _Types of powder The most common type of abrasive particle used with the air-powder polisher is sodium bicarbonate, which is treated to be free-flowing with calcium phosphate and silica. Sodium bicarbonate is a food grade material, and each particle is approximately 74mcminsize.TheMohs’scalehardnessnumberfor sodiumbicarbonateis2.5.Incomparison,Pumicehas a Mohs’ hardness number of 6. Sodium bicarbonate is safe for use on enamel, amalgam, gold, porcelain, implants (titanium) and orthodontic materials. However, its use should be avoided on all types of composites, glass ionomers and luting agents (cements).13 When used on im- plants,airpolishingwithsodiumbicarbonate,should notbedirectedsubgingivally,thusitisthemethodof choice for decontamination of implants. A sodium-free powder for air-powder polishing is available (Fig. 2) (Jet Fresh from DENTSPLY Profes- sional, York, Pa.). Developed for patients who are sodiumintolerant,thispowderismadeofaluminum trihydroxide, which has a Mohs’ hardness number of 2.5 to 3.5 and a particle range in mesh size from 80 mcm to 325 mcm. Aluminumtrihydroxidepowderissafeforenamel; however, it is too abrasive for use on other tooth structures,anditsuseshouldbeavoidedonalldental materials. While using aluminum trihydroxide does not cause surface disruption to porcelain, its use can remove the luting agent, causing a compromise in the margin integrity that can quickly lead to decay.4 hygiene 1_2013 Fig. 2_Jet Fresh prophy powder. (Photos/Provided DENTSPLY Professional unless otherwise noted) Fig. 3_Fill the powder chamber with an abrasive recommended by the manufacturer. Fig. 4_Powder control knob. Fig. 3 Fig. 4 Fig. 2