Comparison of Enamel Microabrasion Techniques: Prema Compound versus a 12-Fluted Finishing Bur Junies A. Coll, D. M. D., M. S.' Patricia Jackson,D.D. S. Howard E. Strussler, D. M 0..E A. D. M.
'
This clinical study was done to compare the effectiveness of microabrasion with Prema Compound versus a high speed 12-flutedbur with water spray in removing incisor hypomineralized defects. Twenty-onepatients had two incisors with enamel surface defects. I t was randomly decided to use Prema Compound on one of the incisors and a 12-fluted bur on the contralateral incisor. One operator did all the procedures, but the tooth's color changes were rated by three observers who rated color photographs pre- and postoperatively, and one of the three rated each patient's teeth in person. The data revealed that there was no significant difference between Prema Compound and the 12-flutedbur in removing incisorhypomineralized defects. Both microabrasion techniques significantlyimproved the tooth's color. but the Prema method took over 9 minutes longer. The 12-fluted bur caused no clinically identifiable marks on the enamel surface. Both techniques were very reliable in removing brown hypomineralized enamel defects, but were far less reliable in removing the white mineralization defects. The 12-fluted bur appeared to be an easier and equally effective alternative to Prema Compound for mineralization defects in incisors.
I
ncisor enamel surfaces can be disturbed during amelogenesiswith resultant brown, white, or yellow stains. These stains can be caused by excessive fluoride consumption, fevers, dehydration, or any factor that disturbs the tooth bud during its formation. Various techniques have been described to remove these superficialfluorosis-type lesions. M'Closkey' described Kane's use of muriatic acid and heat in 1916 to treat these stains effectively.McInnes2was one of the first to devise a bleaching solution of hydrogen peroxide, hydrochloric acid, and ether. Other authors also reported on techniques that were modifications of the McInnes method.- The microabrasion technique described by Croll and Cava.naugh7-*involved rubbing applications of an 18 percent HCl and pumice paste to effectively remove the superficial enamel stain permanently. Croll'o, developed an enamel microabrasion kit, which is now
marketed by Premier Dental Products Company (Nomstown. PA) and termed Prema Compound. The kit contains a new applicator tip used with a 1O:l gear reduction handpiece and a patented "low acid, high abrasive, water-soluble gel-compound."12 Histologic studies on the effect of the acid penetration through the enamel into the pulp show that penetration has been in~ignificant.'~'~ Waggoner et a l l 6 studied nine extracted molars after they were subjected to Croll and Cavanaugh's 18percent HC1-pumice mixture for 10 sequential 5-second applications. They concluded that 25 percent of the labial enamel was removed. In a 1990 abstract, Waggoner et all7reported the amount of enamel removalwith various acid pumice mixtures. The rates of enamel loss per 5-second microabrasion application ranged from 13pm to 26 pm. Croll12reported enamel loss of less than 200 pm fmm enamel microabrasion after personal communication with Dr. U. Jacobson-Hunt. In 1936,G. V. Black18 described treatment of mottled enamel in districts where the condition was endemic. He found the defective and stained enamel was usually in the outer one-fourth to one-third of the labial surface, and the underlying enamel was more normal in color. He felt the enamel could be removed chemicallyor mechanically, and he preferred the mechanical method.
*Clinical Associate Professor. Department of Pediatrfc Dentistry. Universtty of Maryland Dental School. Private Practice limited to Pediatric Dentistry, York. puylsyhranla. f Private RacUce limited to Pedlatric Dentistry. Elkridge. Maryland. $ Associate Professor and Director of Operative Dentistry. Department of Gervral Dentistry. University of Maryland Dental School. Battimore. Mary-
land. Addrrs,reprint mquests to Jamtsk Coll. D.D.S..M.S.. 1600 East Market S M . York. PA 17403. 81991 Decker PeriodicalsInc.
180
Enamel Microabrasion Techniques
Croll'2 has stated that mechanical removal of enamel defects using burs does not give the same effects as Prema Compound. There are no reports in the literature comparing various microabrasion techniques, and only MCloskey described a scale to 'grade" incisor mottling prior to treating patient's teeth with HCl. The purpose of this research was to (1) develop a grading scale to rate the amount of incisor discoloration pre- and postoperatively and (2)to compare the microabrasion technique using Croll's Prema Compound to a technique using a high-speed 12-fluted bur with water spray.
METHODS AND MATERIALS patients treated*They ranged in age There were from 8 to 36 years of age ( g = 17.05years) and consisted of 11 females and 10 males. They were all referred or presented to a private practice in Elkridge, Maryland, for treatment of maxillary incisor brown orwhite discoloration. Each patient signed an informed consent form describing the experiment. A pair of contralateral incisors were treated on each patient resulting in a total of 42 teeth. Thirty-eight teeth were central incisors and four were lateral incisors. Each patient had one of their incisors randomly treated with Prema Compound and was termed technique A. The contralateral incisor was treated by abrading the enamel with a # 12-flutedfmishing bur, #7901Midwest carbide (Fig. 1).The bur was in a high-speed handpiece with a water spray, and was termed technique B. Preoperativeintraoral photographs were taken and postoperative photographs were taken 1 week later. Each technique was timed. A six step rating scale (Fig. 2) was developed to rate the degree of incisor discoloration pre- and postoperatively. The highest rating was a five, which was very esthetic (clear, white, and translucent) and the lowest was a zero, which was very unesthetic and brown.
Figure 2. The six category rating scale used to grade the degree of incisor discoloration (Figs.m-F). A, Rating 5-Most esthetic, white and translucent. (Permission to use photograph 2A was kindly given by Dr. Ted Croll.1
Ngnrc 2. B. Rating 4 - Moderately esthetic, with slight hypomineralized defects.
Figure 2. C. Rating 3
Figure 1. Anumber7901 Midwest carbideburusedinahighspeed hand piece with water spray.
opacities.
181
- Slightly esthetic with
mild white
JOURNAL. OF ESMETIC DENnSTRY VOLUME 3. NUMBER 5 ~ ~ I ~ ~ ~ I I I991 I I K ~ ~ / O ~ ~ ~ I ~ ~ ~ ~
Three people not involved with the dental treatment were trained as raters using the rating scale. After viewing many stained teeth from dental journals, each rater was tested individually by scoring slides of a series of discolored teeth not involved in this study. The correlation between raters was high, ranging from .978 to .990. Due to scheduling constraints, only one of the three raters was available at the dental office to rate the teeth pre- and postoperativeIyin person. All three raters ranked the pre- and postoperative photographs, which were presented in a randomized order. One of the authors (PJ) completed all of the dental procedures. Technique A using Prema Compound utilized a rubber dam sealed with copal varnish. A 1 O : l gear reduction handpiece fitted with the special Prema applicator tips applied the Prema abrasion compound in 20-second intervals for no more than 10applications. Periodic assessment was made of enamel color and labial surface contour. When the operator felt the discoloration had disappeared, improved significantly, or had not improved after 10 applications, the procedure was terminated. The tooth was polished with fluoride prophylaxis paste, and a neutral sodium fluoride gel applied for 4 minutes. Technique B involved the use of a 7901 Midwest 12fluted flame shaped bur. A paper dry angle was modified to cover the contralateral tooth since in technique A a rubber dam covered the contralateral incisor. This was done so as not to bias the operator'sjudgment of the tooth's color. A high-speed finishing bur that had been dulled from previous use was used with water spray. One of the authors (JAC) had found from experience that the dullness prevented over-reductionof the enamel and the water spray prevented drying of the enamel and thus distortion of the tooth's color.Avery light sweeping action from mesial to distal was utilized to abrade the surface stains. When the operator felt the discoloration had disappeared, improved significantly, or had not improved after 15 minutes of abrasion, the procedure was terminated. The same polishing and fluoride treatment as was used with technique A was applied.
Figure 2. D. Rating2 -Slightly unesthetic with obvious white areas. (Permissionto use photograph 2D was kindly given by Dr. Ted Croll.)
Figure 2. E. Rating 1 - Moderately unesthetic lower incisors with mild brown and white enamel defects.
RESULTS Data was gathered from the raters. The raters' scores were usually the same, but when they differed, two agreed and one rater was only one category greater or lesser. The degree of correlation between raters was high (normally .8 to .9). To simplify the data presentation, only the data of the rater who viewed the teeth clinically pre- and postoperatively was used. The data was analiyzed to determine if there was a difference using technique A (Prema)versus technique B (bur)in improving incisor enamel stains. A chi square test showed no significant difference between the two techniques W = 1.68,DF = 4; Table 1, Figs. 3 and 4). The initial incisor discoloration rankings were inspected to see if the two groups differed preoperatively to explain the above findings. The chi square analysis
pioOre 2. F,Rating 0 - Very unesthetic with severe brown hypomineralized areas. (Permission to use photograph 2F was kindly given by Dr. Ted Croll.)
182
Enamel Microabrasion Techniques
Figure 4. B. Postoperatively. both incisors rated a 4 - exhibiting no dflerence between the Prema-treated right incisor versus the bur-treated left incisor.
Figure 3. A, Central incisors preoperatively rated 1. Tooth #8 (right)was treated with Prema and tooth #9was treated with the 12-fluted bur.
T a b l e 1. Comparison of Prema versus 12-fluted Bur in Improving Incisor Surface Staining Post-Op Change in Ranking
-1 0 +1 +2
PREMA TechniqueA
+3
1 9 3 7 1
Totals
21
12-FLUTEDBUR Technique 8 1 11 4 5 0 21
Totals
2
20 7 12 1 42
x2 = 1.68; DF = 4; P = 0.797;No Significant Difference at 0.05.
showed there was no significantdifferencein the group's pxqmative incisor stains @? = 0.133. p = 0.987,DF = 3). The two techniques were then tested to determine if either technique significantly improved the appearance of the discolored incisors. A Student's t-test compared the mean rankings of techniqueA before and after treatment. The t value was 3.80,which was significant at p = 0.05. The same test was runon the mean pre- and postoperative ranldngs of technique B, and the t value was 3.08,which was si@cant at p = 0.05.Therefore, both techniques significantly improved incisor discoloration. The data was then analyzed to see which technique took longer to complete. A Students t-test was used to compare the mean times required for each technique. Technique A (prema) required a mean time of 23.48 minutes to complete, while technique B (bur)required 14.29 minutes (or over 9 minutes less).The t-test value was 4.40, which was significant at p = 0.05, DF = 20. Therefore,the Prematechniquetooksignificantlylonger to complete compared to the 12-fluted bur. The type of initial incisor discoloration and its tendency to improve with either type of treatment was addressed.TherewerehKehreindsorswith~~bbrownish lesions (initial rating of a zero or one) and 91.6
Fil[rue 3. B.P~toperatlvelYboth central incisors were rated 3 showlng equal improvement in their color.
piolna 4. A, uaxillary me wth hypomfnerallzeddefects both rated 2 before treatment. Prema was used on the right central and the 12-flutedbur did the left.
183
percent (1 1 / 12) showed significant improvement (all were rated a 3 or more postoperatively: Fig. 5). The incisors initially rated at two or three (white lesions) showed less reliable improvement. In 60 percent (9/ 15) ofincisors initially rated at two, no improvement in their postoperative ranking was noted (Fig. 6). while 80 percent ( 12/ 15)ofinrisors initially ranked three showed no improvement. Data was gathered from the patients' subjective opinions of treatment. The patientswere asked which of the two treated teeth looked better immediately postoperatively and then again 1 week later. The patients's responses showed no significant difference between treated teeth when the data was analyzed with a chi square analysis. The patients were questioned as to Figure 6. A. Central incisors with well defined white hypomineralized defects. The right central was treated with the 12-flutedbur and the left central with Prema. Both teeth were rated at 2 preoperatively.
Figure 5. A. Preoperative appearance of central incisors with brownish stains rated 1. Tooth #8 was treated with Prema. and #9 with thk 12-flutedbur. Figure 6. B. Postoperatively, the teeth showed little improvement in these well defined lesions, and were rated at 2.
ifeither tooth had been sensitive 1week after treatment and none reported sensitivity. k o m the patients' assessment 1 week later, 62 percent liked the improvement of the teeth regardless of the technique used, 19 percent were unsure, and 19 percent stated there was no improvement regardless of the technique used.
DISCUSSl0N
Figure 5. B,Both teeth improved after treatment and were rated 3. Brownstainsshowed consistent improvementwith both
Both Rema Compound and the 12-fluted bur signiflcantly improved the esthetics of incisors with mineralization defects. This was evident from the results of the three evaluators using the rating scale, and from assessments ofthe Patients. Both had an equal distribution of preoperative enamelmineralizationstain-
techniques.
ing. Enamel microabrasion with Prema Compound did 184
Enamel Microabrasion Techniques
not produce significantlybetter results compared to the 12-fluted bur according to the grading by either the three examiners. or the patients. The 12-fluted bur technique was over 9 minutes faster to perform than the Prema Compound technique. This time factor difference and the minimal expenditure for the a m a mentarium may be a significant issue for the dentist. Croll'o-12 has stated that no matter how carefully mechanical removal of superficial enamel defects are done, identifiable marks can be seen in the enamel. In this study, no identifiablemarks were noted clinically or in any of the postoperative photographs. Croll has statedI0-l2that in the 6 months following Prema Compound microabrasion, the enamel surface undergoes remineralization and attains a supersmooth glasslike surface. If this latter theory is correct, Prema Compound microabrasion may have an advantage over the 12-fluted bur in removing gingival mineralization defects, since postoperative plaque accumulations and recurrent caries would be decreased after using Prema. This theory has not yet been demonstrated and requires further investigation. The microabrasion technique of Croll was found to remove approximately 2 5 percent of the enamel according to Waggoner et al.I6The two incisors were compared postoperatively by the operator (PJ). Both appeared equal in contour when viewed from the incisal. The patients reported no sensitivity in any of the treated teeth 1 week postoperatively. It seemed that the 12fluted bur did not result in any more enamel loss than with Prema Compound. This clinical finding should be investigated histologically to determine its validity. Microabrasion with Prema Compound may work better on incisors with well defined white spots (Fig. 7). Fifteen incisors with severe white defects of this type rated a two preoperatively. Four of eight improved using Prema Compound, while two of seven improved using the 12-flutedbur. This may reflect a chance finding due to the small sample size. Another explanation could be the bleaching action of the acid in Prema Compound may work better to blend the discoloration with the bordering enamel. However, neither technique consistently removed well-defmed white stains. This may be a result of severe white staining not being usually limited to the surface enamel that is removed with either technique. Further research is needed in this area. Both Prema Compound and the 12-fluted bur were reliable in removing brownish stains in 11 of 12 teeth. This agrees with Croll's assessment.". l2 This study's h d i n g s disagree with Croll's assertion12that 50 to 75 percent of white defects can be removed with microabrasion since 33 percent (5/15) of the Prema Compound treated teeth, rated a two or three preoperatively, improved their postoperative rating. From the literature review, only one esthetic rating scale was reported.' and it was used for fluorosis stains. A rating scale such as was used in this study was reliable to fudge incisor color changes objectively by multiple raters. It could be improved upon especiallyfor
Figure 7 . A. Central incisors with well defined hypomineralized white enamel defects. The right was treated with a 12fluted bur and the left with Prema. Both teeth were rated 2.
preUre 7. B, Postoperativecolorofboth teethimproved, but the right central retained its rating of 2 since the defect was still somewhat present. The left central treated with Prema seemed to have had the well defined defect removed and improved its rating to a 3 postoperatively.
those teeth with the white defects when judging their color improvement. Crol112stated that teeth treated with Prema Compound be assessed for color improvement while wet with saliva. This requires removal of the rubber dam and possibly replacement ifretreatment is needed. The 12-fluted bur is used in a wet environment, and thus seemed less cumbersome. For patients with maxillary and mandibular incisors that are stained, the 12-fluted bur technique would be easier to do. If one considered the risk of acid irritation to the patient's or dentist's eyes and the extra time and expense of using Prema compound, the 12-fluted bur technique had none of these disadvantages while showing equal color improvement with no clinically observable enamel surface roughness.
185
CONCLUSIONS
5. Chandra S,Chawla TN. Clinical evaluation of the sandpaper disk method for removing fluorosis stains from teeth. J Am Dent Assoc 1975: 90: 1273-1276. 6. Murrin J R , Barkmeier WW. Chemical treatment ofendemic dental fluorosis. Quintessence Int 1982: 13:363-369. 7. Croll TP. Cavanaugh RR. Enamel color modification by controlled hydrochloricacid-pumice abrasion. I. Technique and examples. Quintessence lnt 1986 17:81-87. 8. Croll TP. Cavanaugh RR. Enamel color modification by controlled hydrochloric acid-pumice abrasion. 11. Further examples. Quintessence Int 1986: 17:157-164. 9. Croll TP. Cavanaugh RR.Hydrochloric acid pumice enamel surface abrasion for color modification: results after six months. Quintessence Int 1986: 17:335-34 1, 10. Croll TP. Enamel microabrasion for removal of superficial discoloration. J Esthet Dent 1989: 1:14-20. 11 . Croll TP. Enamel microabrasion: the technique. Quintessence Int 1989: 20:395-400. 12. Croll TP. Enamel microabrasion for removal of superficial dysmineralization and decalcification defects. J Am Dent Assoc 1990: 120:411415. 13. Baumgartner JC. Reid DE. Pickett AB. Human pulpal reaction to the modified M'lnnes bleaching technique. J Endodont 1983; 9(12):527-529. 14. Jennings RE. Ranley D. Autoradiographic studies of "P penetration into enamel and dentin during acid etching. J Dent Child 1972; 39:69-71. 15. Griffin RD,Grower MF. Ayer WA. Effects of solutions used to treat dental fluorosisonpermeabilityofteeth. J Endodont 1977: 3139-143. 16. WaggonerWF, Johnston WM.Schumann S, Schikowski E. Microabrasionof human enamel in vitro using hydrochloric acid and pumice. Pediatr Dent 1989: 11:319-323. 17. Waggoner WF, Johnston WM. Cieslak J H , Coffey AM Effects of abrasive grits and acid concentration on ename microabrasion. J Dent ResIADRSpecialIssue 1990:69: 1 7 d (Abstr 527). 18. Black AD. G V Blacks work on operative dentistry. Vol. I. 7th Ed. Chicago:Medico-Dent Publishing, 1936: 245-248.
There was no significant difference in the degree of improvement when treating abnormal mineraiizatlon defects in incisors with Prema Compound versus a high-speed 12-fluted bur with water spray. Both techniques significantlyimproved the tooth's discoloration. The preoperative enamel stains were similar for both groups. Teeth treated with Prema Compound required significantly more time to treat (> 9 minutes) than the Iz-fluted bur method. Neither technique caused any discomfort or sensitivity to any of the treated teeth. Patients did not note any esthetic differences between the treated teeth. and 62 percent felt the discolored teeth improved regardless of the technique used. Both techniques worked consistently on brown hypo-mineralized defects but were effective on far less than 50 percent of the white mineralization defects. The 12fluted bur method did not cause any clinically identifiable marks in the enamel's surface and seems to be a faster, less costly alternative to Prema Compound. The rating scale proved to be a reliable and effective means of measuring esthetic enamel differences.
REFERENCES McCloskey RJ.A technique for removal of fluorosis stains. J Am Dent Assoc 1984: 109:63-64. M?Mes J. Removing brown stains from teeth. Ariz Dent J 1966: 12(4):13-15. Bailey RW. Christen AG. Bleaching of vital teeth stained with endemic dental fluorosis. Oral Surg 1968; 26871878. Colon PG. Removing fluorosis stains from teeth [Report 0401).Quintessence lnt 1971;6:8!3-93.
186
'
This clinical study was done to compare the effectiveness of microabrasion with Prema Compound versus a high speed 12-flutedbur with water spray in removing incisor hypomineralized defects. Twenty-onepatients had two incisors with enamel surface defects. I t was randomly decided to use Prema Compound on one of the incisors and a 12-fluted bur on the contralateral incisor. One operator did all the procedures, but the tooth's color changes were rated by three observers who rated color photographs pre- and postoperatively, and one of the three rated each patient's teeth in person. The data revealed that there was no significant difference between Prema Compound and the 12-flutedbur in removing incisorhypomineralized defects. Both microabrasion techniques significantlyimproved the tooth's color. but the Prema method took over 9 minutes longer. The 12-fluted bur caused no clinically identifiable marks on the enamel surface. Both techniques were very reliable in removing brown hypomineralized enamel defects, but were far less reliable in removing the white mineralization defects. The 12-fluted bur appeared to be an easier and equally effective alternative to Prema Compound for mineralization defects in incisors.
I
ncisor enamel surfaces can be disturbed during amelogenesiswith resultant brown, white, or yellow stains. These stains can be caused by excessive fluoride consumption, fevers, dehydration, or any factor that disturbs the tooth bud during its formation. Various techniques have been described to remove these superficialfluorosis-type lesions. M'Closkey' described Kane's use of muriatic acid and heat in 1916 to treat these stains effectively.McInnes2was one of the first to devise a bleaching solution of hydrogen peroxide, hydrochloric acid, and ether. Other authors also reported on techniques that were modifications of the McInnes method.- The microabrasion technique described by Croll and Cava.naugh7-*involved rubbing applications of an 18 percent HCl and pumice paste to effectively remove the superficial enamel stain permanently. Croll'o, developed an enamel microabrasion kit, which is now
marketed by Premier Dental Products Company (Nomstown. PA) and termed Prema Compound. The kit contains a new applicator tip used with a 1O:l gear reduction handpiece and a patented "low acid, high abrasive, water-soluble gel-compound."12 Histologic studies on the effect of the acid penetration through the enamel into the pulp show that penetration has been in~ignificant.'~'~ Waggoner et a l l 6 studied nine extracted molars after they were subjected to Croll and Cavanaugh's 18percent HC1-pumice mixture for 10 sequential 5-second applications. They concluded that 25 percent of the labial enamel was removed. In a 1990 abstract, Waggoner et all7reported the amount of enamel removalwith various acid pumice mixtures. The rates of enamel loss per 5-second microabrasion application ranged from 13pm to 26 pm. Croll12reported enamel loss of less than 200 pm fmm enamel microabrasion after personal communication with Dr. U. Jacobson-Hunt. In 1936,G. V. Black18 described treatment of mottled enamel in districts where the condition was endemic. He found the defective and stained enamel was usually in the outer one-fourth to one-third of the labial surface, and the underlying enamel was more normal in color. He felt the enamel could be removed chemicallyor mechanically, and he preferred the mechanical method.
*Clinical Associate Professor. Department of Pediatrfc Dentistry. Universtty of Maryland Dental School. Private Practice limited to Pediatric Dentistry, York. puylsyhranla. f Private RacUce limited to Pedlatric Dentistry. Elkridge. Maryland. $ Associate Professor and Director of Operative Dentistry. Department of Gervral Dentistry. University of Maryland Dental School. Battimore. Mary-
land. Addrrs,reprint mquests to Jamtsk Coll. D.D.S..M.S.. 1600 East Market S M . York. PA 17403. 81991 Decker PeriodicalsInc.
180
Enamel Microabrasion Techniques
Croll'2 has stated that mechanical removal of enamel defects using burs does not give the same effects as Prema Compound. There are no reports in the literature comparing various microabrasion techniques, and only MCloskey described a scale to 'grade" incisor mottling prior to treating patient's teeth with HCl. The purpose of this research was to (1) develop a grading scale to rate the amount of incisor discoloration pre- and postoperatively and (2)to compare the microabrasion technique using Croll's Prema Compound to a technique using a high-speed 12-fluted bur with water spray.
METHODS AND MATERIALS patients treated*They ranged in age There were from 8 to 36 years of age ( g = 17.05years) and consisted of 11 females and 10 males. They were all referred or presented to a private practice in Elkridge, Maryland, for treatment of maxillary incisor brown orwhite discoloration. Each patient signed an informed consent form describing the experiment. A pair of contralateral incisors were treated on each patient resulting in a total of 42 teeth. Thirty-eight teeth were central incisors and four were lateral incisors. Each patient had one of their incisors randomly treated with Prema Compound and was termed technique A. The contralateral incisor was treated by abrading the enamel with a # 12-flutedfmishing bur, #7901Midwest carbide (Fig. 1).The bur was in a high-speed handpiece with a water spray, and was termed technique B. Preoperativeintraoral photographs were taken and postoperative photographs were taken 1 week later. Each technique was timed. A six step rating scale (Fig. 2) was developed to rate the degree of incisor discoloration pre- and postoperatively. The highest rating was a five, which was very esthetic (clear, white, and translucent) and the lowest was a zero, which was very unesthetic and brown.
Figure 2. The six category rating scale used to grade the degree of incisor discoloration (Figs.m-F). A, Rating 5-Most esthetic, white and translucent. (Permission to use photograph 2A was kindly given by Dr. Ted Croll.1
Ngnrc 2. B. Rating 4 - Moderately esthetic, with slight hypomineralized defects.
Figure 2. C. Rating 3
Figure 1. Anumber7901 Midwest carbideburusedinahighspeed hand piece with water spray.
opacities.
181
- Slightly esthetic with
mild white
JOURNAL. OF ESMETIC DENnSTRY VOLUME 3. NUMBER 5 ~ ~ I ~ ~ ~ I I I991 I I K ~ ~ / O ~ ~ ~ I ~ ~ ~ ~
Three people not involved with the dental treatment were trained as raters using the rating scale. After viewing many stained teeth from dental journals, each rater was tested individually by scoring slides of a series of discolored teeth not involved in this study. The correlation between raters was high, ranging from .978 to .990. Due to scheduling constraints, only one of the three raters was available at the dental office to rate the teeth pre- and postoperativeIyin person. All three raters ranked the pre- and postoperative photographs, which were presented in a randomized order. One of the authors (PJ) completed all of the dental procedures. Technique A using Prema Compound utilized a rubber dam sealed with copal varnish. A 1 O : l gear reduction handpiece fitted with the special Prema applicator tips applied the Prema abrasion compound in 20-second intervals for no more than 10applications. Periodic assessment was made of enamel color and labial surface contour. When the operator felt the discoloration had disappeared, improved significantly, or had not improved after 10 applications, the procedure was terminated. The tooth was polished with fluoride prophylaxis paste, and a neutral sodium fluoride gel applied for 4 minutes. Technique B involved the use of a 7901 Midwest 12fluted flame shaped bur. A paper dry angle was modified to cover the contralateral tooth since in technique A a rubber dam covered the contralateral incisor. This was done so as not to bias the operator'sjudgment of the tooth's color. A high-speed finishing bur that had been dulled from previous use was used with water spray. One of the authors (JAC) had found from experience that the dullness prevented over-reductionof the enamel and the water spray prevented drying of the enamel and thus distortion of the tooth's color.Avery light sweeping action from mesial to distal was utilized to abrade the surface stains. When the operator felt the discoloration had disappeared, improved significantly, or had not improved after 15 minutes of abrasion, the procedure was terminated. The same polishing and fluoride treatment as was used with technique A was applied.
Figure 2. D. Rating2 -Slightly unesthetic with obvious white areas. (Permissionto use photograph 2D was kindly given by Dr. Ted Croll.)
Figure 2. E. Rating 1 - Moderately unesthetic lower incisors with mild brown and white enamel defects.
RESULTS Data was gathered from the raters. The raters' scores were usually the same, but when they differed, two agreed and one rater was only one category greater or lesser. The degree of correlation between raters was high (normally .8 to .9). To simplify the data presentation, only the data of the rater who viewed the teeth clinically pre- and postoperatively was used. The data was analiyzed to determine if there was a difference using technique A (Prema)versus technique B (bur)in improving incisor enamel stains. A chi square test showed no significant difference between the two techniques W = 1.68,DF = 4; Table 1, Figs. 3 and 4). The initial incisor discoloration rankings were inspected to see if the two groups differed preoperatively to explain the above findings. The chi square analysis
pioOre 2. F,Rating 0 - Very unesthetic with severe brown hypomineralized areas. (Permission to use photograph 2F was kindly given by Dr. Ted Croll.)
182
Enamel Microabrasion Techniques
Figure 4. B. Postoperatively. both incisors rated a 4 - exhibiting no dflerence between the Prema-treated right incisor versus the bur-treated left incisor.
Figure 3. A, Central incisors preoperatively rated 1. Tooth #8 (right)was treated with Prema and tooth #9was treated with the 12-fluted bur.
T a b l e 1. Comparison of Prema versus 12-fluted Bur in Improving Incisor Surface Staining Post-Op Change in Ranking
-1 0 +1 +2
PREMA TechniqueA
+3
1 9 3 7 1
Totals
21
12-FLUTEDBUR Technique 8 1 11 4 5 0 21
Totals
2
20 7 12 1 42
x2 = 1.68; DF = 4; P = 0.797;No Significant Difference at 0.05.
showed there was no significantdifferencein the group's pxqmative incisor stains @? = 0.133. p = 0.987,DF = 3). The two techniques were then tested to determine if either technique significantly improved the appearance of the discolored incisors. A Student's t-test compared the mean rankings of techniqueA before and after treatment. The t value was 3.80,which was significant at p = 0.05. The same test was runon the mean pre- and postoperative ranldngs of technique B, and the t value was 3.08,which was si@cant at p = 0.05.Therefore, both techniques significantly improved incisor discoloration. The data was then analyzed to see which technique took longer to complete. A Students t-test was used to compare the mean times required for each technique. Technique A (prema) required a mean time of 23.48 minutes to complete, while technique B (bur)required 14.29 minutes (or over 9 minutes less).The t-test value was 4.40, which was significant at p = 0.05, DF = 20. Therefore,the Prematechniquetooksignificantlylonger to complete compared to the 12-fluted bur. The type of initial incisor discoloration and its tendency to improve with either type of treatment was addressed.TherewerehKehreindsorswith~~bbrownish lesions (initial rating of a zero or one) and 91.6
Fil[rue 3. B.P~toperatlvelYboth central incisors were rated 3 showlng equal improvement in their color.
piolna 4. A, uaxillary me wth hypomfnerallzeddefects both rated 2 before treatment. Prema was used on the right central and the 12-flutedbur did the left.
183
percent (1 1 / 12) showed significant improvement (all were rated a 3 or more postoperatively: Fig. 5). The incisors initially rated at two or three (white lesions) showed less reliable improvement. In 60 percent (9/ 15) ofincisors initially rated at two, no improvement in their postoperative ranking was noted (Fig. 6). while 80 percent ( 12/ 15)ofinrisors initially ranked three showed no improvement. Data was gathered from the patients' subjective opinions of treatment. The patientswere asked which of the two treated teeth looked better immediately postoperatively and then again 1 week later. The patients's responses showed no significant difference between treated teeth when the data was analyzed with a chi square analysis. The patients were questioned as to Figure 6. A. Central incisors with well defined white hypomineralized defects. The right central was treated with the 12-flutedbur and the left central with Prema. Both teeth were rated at 2 preoperatively.
Figure 5. A. Preoperative appearance of central incisors with brownish stains rated 1. Tooth #8 was treated with Prema. and #9 with thk 12-flutedbur. Figure 6. B. Postoperatively, the teeth showed little improvement in these well defined lesions, and were rated at 2.
ifeither tooth had been sensitive 1week after treatment and none reported sensitivity. k o m the patients' assessment 1 week later, 62 percent liked the improvement of the teeth regardless of the technique used, 19 percent were unsure, and 19 percent stated there was no improvement regardless of the technique used.
DISCUSSl0N
Figure 5. B,Both teeth improved after treatment and were rated 3. Brownstainsshowed consistent improvementwith both
Both Rema Compound and the 12-fluted bur signiflcantly improved the esthetics of incisors with mineralization defects. This was evident from the results of the three evaluators using the rating scale, and from assessments ofthe Patients. Both had an equal distribution of preoperative enamelmineralizationstain-
techniques.
ing. Enamel microabrasion with Prema Compound did 184
Enamel Microabrasion Techniques
not produce significantlybetter results compared to the 12-fluted bur according to the grading by either the three examiners. or the patients. The 12-fluted bur technique was over 9 minutes faster to perform than the Prema Compound technique. This time factor difference and the minimal expenditure for the a m a mentarium may be a significant issue for the dentist. Croll'o-12 has stated that no matter how carefully mechanical removal of superficial enamel defects are done, identifiable marks can be seen in the enamel. In this study, no identifiablemarks were noted clinically or in any of the postoperative photographs. Croll has statedI0-l2that in the 6 months following Prema Compound microabrasion, the enamel surface undergoes remineralization and attains a supersmooth glasslike surface. If this latter theory is correct, Prema Compound microabrasion may have an advantage over the 12-fluted bur in removing gingival mineralization defects, since postoperative plaque accumulations and recurrent caries would be decreased after using Prema. This theory has not yet been demonstrated and requires further investigation. The microabrasion technique of Croll was found to remove approximately 2 5 percent of the enamel according to Waggoner et al.I6The two incisors were compared postoperatively by the operator (PJ). Both appeared equal in contour when viewed from the incisal. The patients reported no sensitivity in any of the treated teeth 1 week postoperatively. It seemed that the 12fluted bur did not result in any more enamel loss than with Prema Compound. This clinical finding should be investigated histologically to determine its validity. Microabrasion with Prema Compound may work better on incisors with well defined white spots (Fig. 7). Fifteen incisors with severe white defects of this type rated a two preoperatively. Four of eight improved using Prema Compound, while two of seven improved using the 12-flutedbur. This may reflect a chance finding due to the small sample size. Another explanation could be the bleaching action of the acid in Prema Compound may work better to blend the discoloration with the bordering enamel. However, neither technique consistently removed well-defmed white stains. This may be a result of severe white staining not being usually limited to the surface enamel that is removed with either technique. Further research is needed in this area. Both Prema Compound and the 12-fluted bur were reliable in removing brownish stains in 11 of 12 teeth. This agrees with Croll's assessment.". l2 This study's h d i n g s disagree with Croll's assertion12that 50 to 75 percent of white defects can be removed with microabrasion since 33 percent (5/15) of the Prema Compound treated teeth, rated a two or three preoperatively, improved their postoperative rating. From the literature review, only one esthetic rating scale was reported.' and it was used for fluorosis stains. A rating scale such as was used in this study was reliable to fudge incisor color changes objectively by multiple raters. It could be improved upon especiallyfor
Figure 7 . A. Central incisors with well defined hypomineralized white enamel defects. The right was treated with a 12fluted bur and the left with Prema. Both teeth were rated 2.
preUre 7. B, Postoperativecolorofboth teethimproved, but the right central retained its rating of 2 since the defect was still somewhat present. The left central treated with Prema seemed to have had the well defined defect removed and improved its rating to a 3 postoperatively.
those teeth with the white defects when judging their color improvement. Crol112stated that teeth treated with Prema Compound be assessed for color improvement while wet with saliva. This requires removal of the rubber dam and possibly replacement ifretreatment is needed. The 12-fluted bur is used in a wet environment, and thus seemed less cumbersome. For patients with maxillary and mandibular incisors that are stained, the 12-fluted bur technique would be easier to do. If one considered the risk of acid irritation to the patient's or dentist's eyes and the extra time and expense of using Prema compound, the 12-fluted bur technique had none of these disadvantages while showing equal color improvement with no clinically observable enamel surface roughness.
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CONCLUSIONS
5. Chandra S,Chawla TN. Clinical evaluation of the sandpaper disk method for removing fluorosis stains from teeth. J Am Dent Assoc 1975: 90: 1273-1276. 6. Murrin J R , Barkmeier WW. Chemical treatment ofendemic dental fluorosis. Quintessence Int 1982: 13:363-369. 7. Croll TP. Cavanaugh RR. Enamel color modification by controlled hydrochloricacid-pumice abrasion. I. Technique and examples. Quintessence lnt 1986 17:81-87. 8. Croll TP. Cavanaugh RR. Enamel color modification by controlled hydrochloric acid-pumice abrasion. 11. Further examples. Quintessence Int 1986: 17:157-164. 9. Croll TP. Cavanaugh RR.Hydrochloric acid pumice enamel surface abrasion for color modification: results after six months. Quintessence Int 1986: 17:335-34 1, 10. Croll TP. Enamel microabrasion for removal of superficial discoloration. J Esthet Dent 1989: 1:14-20. 11 . Croll TP. Enamel microabrasion: the technique. Quintessence Int 1989: 20:395-400. 12. Croll TP. Enamel microabrasion for removal of superficial dysmineralization and decalcification defects. J Am Dent Assoc 1990: 120:411415. 13. Baumgartner JC. Reid DE. Pickett AB. Human pulpal reaction to the modified M'lnnes bleaching technique. J Endodont 1983; 9(12):527-529. 14. Jennings RE. Ranley D. Autoradiographic studies of "P penetration into enamel and dentin during acid etching. J Dent Child 1972; 39:69-71. 15. Griffin RD,Grower MF. Ayer WA. Effects of solutions used to treat dental fluorosisonpermeabilityofteeth. J Endodont 1977: 3139-143. 16. WaggonerWF, Johnston WM.Schumann S, Schikowski E. Microabrasionof human enamel in vitro using hydrochloric acid and pumice. Pediatr Dent 1989: 11:319-323. 17. Waggoner WF, Johnston WM. Cieslak J H , Coffey AM Effects of abrasive grits and acid concentration on ename microabrasion. J Dent ResIADRSpecialIssue 1990:69: 1 7 d (Abstr 527). 18. Black AD. G V Blacks work on operative dentistry. Vol. I. 7th Ed. Chicago:Medico-Dent Publishing, 1936: 245-248.
There was no significant difference in the degree of improvement when treating abnormal mineraiizatlon defects in incisors with Prema Compound versus a high-speed 12-fluted bur with water spray. Both techniques significantlyimproved the tooth's discoloration. The preoperative enamel stains were similar for both groups. Teeth treated with Prema Compound required significantly more time to treat (> 9 minutes) than the Iz-fluted bur method. Neither technique caused any discomfort or sensitivity to any of the treated teeth. Patients did not note any esthetic differences between the treated teeth. and 62 percent felt the discolored teeth improved regardless of the technique used. Both techniques worked consistently on brown hypo-mineralized defects but were effective on far less than 50 percent of the white mineralization defects. The 12fluted bur method did not cause any clinically identifiable marks in the enamel's surface and seems to be a faster, less costly alternative to Prema Compound. The rating scale proved to be a reliable and effective means of measuring esthetic enamel differences.
REFERENCES McCloskey RJ.A technique for removal of fluorosis stains. J Am Dent Assoc 1984: 109:63-64. M?Mes J. Removing brown stains from teeth. Ariz Dent J 1966: 12(4):13-15. Bailey RW. Christen AG. Bleaching of vital teeth stained with endemic dental fluorosis. Oral Surg 1968; 26871878. Colon PG. Removing fluorosis stains from teeth [Report 0401).Quintessence lnt 1971;6:8!3-93.
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