Sixty-year results of eliminating brown fluorosis stain using hydrochloric acid. Anterior teeth treated, posterior teeth untreated
Croll used a combination of 18 % hydrochloric acid mixed with fine grit laboratory pumice with the idea that combining chemical erosion with mechanical abrasion would also reduce the enamel surface microscopically, but more rapidly, and with the clinician in control. In 1986, Croll and Cavanaugh first reported this type of approach and termed the treatment “enamel microabrasion” (EM) (Croll and Cavanaugh 1986a, b). After much more experience, a textbook followed (Croll 1991).
Enamel microabrasion is analogous to dermabrasion on skin surfaces. It represents a most conservative method of removing intrinsic, yet superficial, enamel dysmineralization (ibid, pg 22), decalcification, and texture defects avoiding the need for restorative masking with artificial materials such as bonded resin-based composite or bonded porcelain veneers. Successful microabrasion removes an insignificant and unrecognizable amount of surface enamel and with it, the offending discolored or “maltextured” layer. Oftentimes, enamel microabrasion can be combined with dental bleaching (Haywood and Heymann 1989) for optimum enhancement of tooth appearance (Cvitko et al. 1992; Killian 1993; Croll 1992, 1998).
Enamel microabrasion has become a routine clinical procedure in dentistry (ADA treatment code D9970) and commercial microabrasion products (PREMA®, Premier Dental Products, Plymouth Meeting, PA) (OPALUSTRE®, Ultradent Products, South Jordan, UT) are available to facilitate treatment. These products contain a low concentration of hydrochloric acid (6–9 %) and silicon carbide abrasive powder in a silica gel, for rotary application. Research has shown that use of these products, followed by natural remineralization, creates a lustrous enamel surface that not only is more resistant to acid challenge, but also accumulates less dental plaque than untreated surfaces (Segura et al. 1997a, b). Polarized light microscope and scanning electron microscope studies have revealed that microabrasion results in an enamel surface with a superficial layer of compacted, aprismatic mineral that gives a glass-like clinical appearance. The microabrasion technique removes some surface enamel but also packs some of the abraded calcium and phosphate into the interprismatic spaces to create a highly dense and polished surface (Fig. 9.2) (Berg and Donly 1991; Donly et al. 1992). Combining mechanical abrasion and chemical erosion inspired the terms “abrosion effect” (Donly et al. 1992) and its result, the “enamel glaze.”
A scanning electron microscopic view of the polished enamel surface following microabrasion and the natural appearance of enamel below the polished surface in this fractured (fx) enamel specimen
9.2 Enamel Microabrasion Procedure
The enamel microabrasion procedure can be outlined as follows:
Determination is made whether the tooth discoloration or texture defect is relatively superficial. Enamel microabrasion is not indicated for tooth discolorations such as seen with tetracycline dentinal stain, dentinogenesis imperfecta, or deep enamel hypoplastic or hypocalcification defects. EM treatment is indicated for enamel dysmineralization discolorations such as seen with brown and white fluorosis, idiopathic brown or white stain, or superficial enamel texture anomalies.
Pretreatment photographs are always advised, both for medico-legal considerations, and for education of the patient and parents.
Local anesthesia is used only if needed to facilitate rubber dam placement.
Rubber dam application or isolation with OpalDam® or OpalDam Green® (Ultradent Products, South Jordan, UT) is recommended. Protective eyewear for the patient is mandatory.
To hasten treatment results, a cylindrical diamond bur can be used at slow speed, to initiate enamel surface microreduction (Croll 1993).
Using either the PREMA® Enamel Microabrasion Compound with rotary polishing cups or OPALUSTRE® with OpalCups™, a small portion of slurry is applied to the tooth surface. A high-torque gear-reduction hand piece can be used, but with careful application to avoid splattering, treatment can be achieved safely with a standard slow-speed angle. After 5–10 s, using moderate pressure, the microabrasion compound is rinsed with water, and results observed.
Five 10-s applications are repeated until the coloration defect is eliminated. Determination of tooth appearance should be made while the tooth is wet.
After completion of microabrasion, the treated teeth should be saturated for several minutes with a fluoride-containing gel.
9.3 Representative Cases
Enamel microabrasion treatment of three patients is documented below. One had decalcification (Croll and Bullock 1994), another, enamel dysmineralization, and the third, congenital enamel texture malformation (Killian and Croll 1990). A fourth case is shown with 27-year postoperative enamel microabrasion results combined with tooth bleaching in the adult years.
9.3.1 Case One
A 16-year-old boy had white decalcification markings in the gingival half of his maxillary anterior teeth, related to inadequate oral hygiene during his orthodontic therapy (Figs. 9.3a–d). There was a caries lesion associated with the decalcification on the maxillary left canine tooth (Fig. 9.3b). The maxillary premolars also had facial decalcification spots. A small shear fracture was noted on the maxillary left first premolar, perhaps occurring during orthodontic bracket removal (Fig. 9.3b). The fractured region was smoothed with a fine-tipped diamond bur. White decalcification areas were seen on some mandibular teeth also, but none were noticeable when the patient spoke or smiled, and none had associated caries.
WordPress theme by UFO themes