|Year : 2019 | Volume
| Issue : 1 | Page : 34-39
Clinical efficacy of hydrochloric acid and phosphoric acid in microabrasion technique for the treatment of different severities of dental fluorosis: An in vivo comparison
Dipanshu Kumar1, Aparna Singh2, Chitrita Gupta Mukherjee2, Asib Ahmed3, Arpanna Singh2, Mukesh Kumar Hasija4, Siddharth Anand2
1 Department of Pedodontics and Preventive Dentistry, Inderprastha Dental College and Hospital, Ghaziabad, India
2 Department of Pedodontics and Preventive Dentistry, Buddha Institute of Dental Sciences and Hospital, Patna, Bihar, India
3 Department of Pedodontics and Preventive Dentistry, Institute of Dental Sciences and Hospital, Modinagar, Uttar Pradesh, India
4 Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi, India
|Date of Web Publication||19-Jun-2019|
Dr. Mukesh Kumar Hasija
Department of Conservative Dentistry and Endodontics, Faculty of Dentistry, Jamia Millia Islamia, New Delhi
Source of Support: None, Conflict of Interest: None
Aim: The aim of this study was to evaluate and to compare the clinical efficacy of two compounds (hydrochloric acid and phosphoric acid) in microabrasion in terms of degree of stain removal (DSR) and improvement of appearance for the different severities of dental fluorosis. The mean time and number of applications required by the two experimental compounds were also compared.
Methodology: Children between the age group of 9–14 years with dental fluorosis to two or more fluorozed anterior permanent teeth were included in the study. The Dean's Fluorosis Index was used to classify each tooth, and they were randomly selected into mild (Group I), moderate (Group II), and severe (Group III) groups of fluorosis. Ten teeth from each of these groups were randomly allotted for undergoing microabrasion using 18% HCl with pumice and other 10 teeth using 37% phosphoric acid with pumice. Colored preoperative and postoperative photographs were taken for each patient and analyzed for improvement in appearance and DSR. Time and number of applications and parent–patient response with both the compounds were also recorded. The results were tabulated and statistically analyzed.
Results: The results of the present study showed that a nonsignificant difference existed in DSR and improvement in appearance between the two compounds of microabrasion for all the three degrees of dental fluorosis. Significantly lesser time was taken by HCl in mild and moderate fluorosis. Significantly lesser number of applications was required with HCl for moderate fluorosis. Nonsignificant difference existed for parent-patient response with both the compounds for all the severities of dental fluorosis.
Conclusion: 18% HCl with pumice and 37% phosphoric acid with pumice both can be used for microabrasion for all the severities of dental fluorosis. The time and number of applications using HCl were lesser; therefore, it should be preferred over H3PO4 for all the severities of fluorosis.
Keywords: Fluorosis, hydrochloric acid, microabrasion, phosphoric acid
|How to cite this article:|
Kumar D, Singh A, Mukherjee CG, Ahmed A, Singh A, Hasija MK, Anand S. Clinical efficacy of hydrochloric acid and phosphoric acid in microabrasion technique for the treatment of different severities of dental fluorosis: An in vivo comparison. Endodontology 2019;31:34-9
|How to cite this URL:|
Kumar D, Singh A, Mukherjee CG, Ahmed A, Singh A, Hasija MK, Anand S. Clinical efficacy of hydrochloric acid and phosphoric acid in microabrasion technique for the treatment of different severities of dental fluorosis: An in vivo comparison. Endodontology [serial online] 2019 [cited 2021 Jun 14];31:34-9. Available from: https://www.endodontologyonweb.org/text.asp?2019/31/1/34/260521
| Introduction|| |
The most common cause of intrinsic tooth discoloration is dental fluorosis. Fluorosis is mainly due to chronic ingestion of high fluoride content for a prolonged period. The severity of dental fluorosis ranges from subsurface hypomineralization with/without porosity of enamel to whole thickness of enamel and ranges from yellow to dark brown stains with/without pitting. Discolored anterior teeth negatively affect the psychological, emotional, and social development of the child because of the esthetic concerns. Intervention at this stage is necessary for children to prevent any damage to the personality development of child and loss of weaken enamel. The suggested treatment alternatives for such fluorozed teeth involve direct resin restorations or composite veneers, porcelain laminates or veneers, and crowns.
However, all these alternatives are invasive involving loss of considerable enamel structure which is needed to be avoided in children with immature teeth having large pulp chambers. Bleaching is an accepted noninvasive procedure but may cause the problem of postoperative sensitivity in vital tooth. Hence, the most conservative, safe, atraumatic procedure with least drawbacks for fluorozed teeth in children is microabrasion. Microabrasion technique involves employing a mixture of 37% phosphoric acid gel in extra fine grain pumice or 18% hydrochloric acid in pumice or 6.6% and 10% hydrochloric acid with silica carbide particles, with rubber cup in slow rotating motion to the areas of discoloration or white opacities. Another advantage of microabrasion technique is that it leaves the treated enamel surface as highly polished which minimizes the cariogenic bacteria colonization and render it more resistant to demineralization.
The present study was undertaken to evaluate and to compare the clinical efficacy of two compounds (hydrochloric acid and phosphoric acid) in microabrasion in terms of degree of stain removal (DSR) and improvement of appearance (IA) for the different severities of dental fluorosis. The mean time and number of applications required by the two experimental compounds were also compared. Parent satisfaction for the two techniques was also evaluated and compared.
| Methodology|| |
Children between the age group of 9–14 years with dental fluorosis visiting the outpatient department of department of pedodontics and preventive dentistry were clinically examined by the two experienced observers (A and B). Participants with caries on anterior teeth or with extremely poor oral hygiene or periodontal disease were excluded from the study. Participants with two or more fluorozed anterior permanent teeth which at least two-third erupted were included in the study. The teeth were first cleaned with prophylactic paste and dried using cotton rolls, and within 30 s of drying, degree of staining was determined by the two observers separately. The Dean's Fluorosis Index was used to classify each tooth into mild, moderate, or severe groups of fluorosis. For the present study, the teeth with questionable category with score 0.5 were not included and very mild category (score 1) was combined with the mild group. Each participant provided the history of fluoride ingestion as the etiological factor of enamel stains and presented with a bilateral symmetrical distribution of stains.
From the fluorozed teeth, 20 teeth were randomly selected under each of the mild (Group I), moderate (Group II), and severe (Group III) groups of fluorosis. Ten teeth from each of these groups were randomly allotted for undergoing microabrasion using 18% HCl with pumice and other 10 teeth using 37% phosphoric acid with pumice. Parents of the selected patients were informed about the procedure and purpose of the study and written consent was obtained.
Colored preoperative photographs were taken for each patient. All the photographs, preoperative [Figure 1]a and postoperative [Figure 1]b for both the microabrasion agents were taken at the prestandardized settings of the same camera in the same dental unit.
|Figure 1: (a) Preoperative view showing dental fluorosis (b) Postoperative view showing the clinical efficacy of phosphoric acid in microabrasion technique|
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Microabrasion procedure for each tooth was carried out by the trained operator. As for all microabrasion procedures, the eyes of the patient, clinician, and dental assistant were shielded with protective glasses. Before treatment, rubber cup prophylaxis was done with pumice/water slurry, rinsed thoroughly, and dried. The gingival tissues were protected with vaseline while the tooth was isolated with a rubber dam to avoid contact between the acidic material and other teeth as well as soft tissues of the mouth. The two study pastes were prepared using 18% HCl or 37% phosphoric acid (Dentaltec, Cathec Industrial Ltd., Rio do Sul, SC, Brazil) mixed together with pumice to make a stable, consistent paste. The paste was applied with a contra-angle handpiece in slow speed for 20 s in circular movements on the entire surface of stained enamel. The procedure was repeated with each session of application of 20 s. After every application, the tooth was liberally rinsed with copious amount of water to remove the paste, and the treated surface was then evaluated by the experienced observer for the remaining stains of fluorosis. The experienced observer guided the continuation of procedure depending on the presence of remaining stains and the thickness of labial enamel. The procedure was discontinued, when experienced observer found complete removal of stains or for other reasons, it was needed to be stopped (enamel getting too thin or tooth getting sensitive). The treatment for each category of fluorosis was carried out in a single appointment.
The treatment was followed by removing the rubber dam and applying neutral sodium fluoride at 2% (DFL, Indústria e Comércio S/A, Jacarepaguá, RJ, Brazil) for 4 min. The patient was instructed not to rinse for 30 min. Instructions related to oral hygiene maintenance and caries prevention were given to all patients.
Postoperative photographs were taken after an hour in wet condition and blotting the excess moisture. All the photographs (preoperative and postoperative) were assessed and scored by the two experienced observers with interobserver and intraobserver agreement at 85% for each case. Esthetic scores regarding IA and DSR were recorded using visual analog scale ranging from 1 (no improvement in appearance or stain not removed at all) to 7 (exceptional improvement in appearance or stain totally removed). The mean scores for IA and DSR for the two techniques were measured and analyzed using Mann–Whitney test and t-test.
The treatment time and number of applications were recorded for each tooth and means were calculated and compared using the Mann–Whitney test for both the techniques for each of the three study groups. The attending parents were asked to assess the esthetic improvement by answering – (a) satisfied, (b) very satisfied, and (c) not satisfied. Their answers were tabulated and compared.
All the patients were recalled after 3 months to evaluate the stability of the results.
| Results|| |
The results of the present study showed that a nonsignificant difference existed in DSR and improvement in appearance between the two compounds of microabrasion for all the three degrees of dental fluorosis [Table 1] and [Table 2]. The mean scores for improvement in appearance on a scale from 1 to 7, with HCl-pumice compound in cases of mild, moderate, and severe fluorosis were 6.80 ± 0.63, 5.70 ± 2.35, and 3.00 ± 1.09, respectively, while with H3 PO4-pumice compound, it was 6.80 ± 0.63, 5.10 ± 2.88, and 2.90 ± 1.87, respectively [Table 1]. The mean scores for DSR with HCl-pumice compound in cases of mild, moderate, and severe fluorosis were 6.80 ± 0.63, 5.80 ± 2.29, and 3.50 ± 2.87, respectively, while with H3 PO4-pumice compound, it was 6.50 ± 1.08, 5.50 ± 2.32, and 3.30 ± 2.87, respectively [Table 2]. Only three teeth with severe fluorosis from 10 showed exceptional improvement (complete removal of stains) in appearance and stain removal with both the compounds.
|Table 1: Comparison of improvement in appearance between the two compounds for different degree of dental fluorosis|
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|Table 2: Comparison of the degree of stain removal between the two compounds for different degree of dental fluorosis|
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The mean time taken for HCl-pumice compound in cases of mild, moderate, and severe fluorosis was 78.00 ± 14.75, 122 ± 14.75, and 160 ± 13.21 seconds, respectively, while with H3 PO4-Pumice compound, it was 86 ± 13.49, 134 ± 13.50, and 166 ± 16.55 s, respectively. The mean number of applications for HCl-pumice compound in cases of mild, moderate, and severe fluorosis was 4.00 ± 0.81, 6.10 ± 0.73, and 8 ± 0.66, respectively, while with H3 PO4-Pumice compound, it was 4.30 ± 0.67, 6.70 ± 0.67, and 8.30 ± 0.82, respectively. The mean time taken with HCl-pumice was significantly lesser for mild and moderate dental fluorosis; however, the mean number of applications was significantly lesser only for moderate fluorosis compared to H3 PO4-Pumice compound [Table 3] and [Table 4].
|Table 3: Comparison of time of applications between the two compounds for different degree of dental fluorosis|
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|Table 4: Comparison of number of applications between the two compounds for different degree of dental fluorosis|
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Nine, seven, and three parents from 10 responded very satisfactory for esthetic appearance after treatment with both the microabrasion compounds for mild, moderate, and severe groups of fluorosis. The difference in parent–patient satisfaction response for both the study compounds was nonsignificant in all severities of fluorosis [Table 5].
|Table 5: Comparison of parent-patient response for esthetic appearance between the two compounds for different degree of dental fluorosis|
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| Discussion|| |
The increasing desire for excellent dental esthetic has led to numerous scientific and technological advances in various aspects of dentistry, including treatment techniques for stained teeth, it has been postulated that excessive fluoride causes interference with ameloblasts activity during mineralization phase of tooth development that causes these defects.
Symmetric bilateral distribution of stains and a history of excessive fluoride intake during the early years of life were used to rule out the diagnosis of dental fluorosis in selected cases for the present study.
Examination and selection of cases as well as preoperative and postoperative evaluation and scoring of photographs were carried out by two experienced observers (A and B) after proper training and interexaminer and intraexaminer consistency of results.
Different treatment modalities have been suggested for different severities of dental fluorosis ranging from bleaching to full coverage crowns. The minimally invasive microabrasion technique has shown excellent results for treating superficial enamel intrinsic stains, particularly caused by fluorosis and even superficial enamel surface irregularities with hard texture. This technique involved the use of products that basically composed of an acid in various concentrations mixed with an abrasive such as silica carbide or pumice., Acids used in the present study comprised 18% HCl and 37% H3 PO4. Lesser concentration of HCl was used being it more corrosive.
The results of the present study had shown complete removal of stains and exceptional improvement in appearance with both the microabrasion compounds in almost all the teeth with mild fluorosis and maximum number of teeth with moderate fluorosis while only few teeth with severe fluorosis responded to microabrasion.
Moreover, almost all the parents and patients were either satisfied or very satisfied with the postoperative results in mild and moderate fluorosis with both the compounds while in cases of severe fluorosis almost half of them were not satisfied with the treatment results. Therefore, microabrasion was found to be the definitive treatment for mild and moderate fluorosis only.
Train et al., Loguercio et al., and Sinha et al. also have similar observations in various studies.,, The reason behind it was explained by Thylstrup and Fejerskov who suggested that the mild fluorotic lesions lie in the outer 80–100 μm of enamel. The microabrasion technique generally removes the first 25–200 μm of surface enamel, depending on the acid concentration and number or time of application. The moderate and severe fluorosis lesions lie too deep to be effectively treated by microabrasion.,
However, as fluorotic stains are confined to superficial layers of enamel, and it is difficult to estimate clinically the depth of intrinsic stain and enamel surface irregularities; therefore, microabrasion should be used as the first line of treatment for all such cases before going for other invasive procedures. This was also observed in the present study that three cases of severe fluorosis from ten have responded exceptionally regarding DSR and improvement in appearance. The same was observed by other authors also.
When comparing the clinical efficacy of two microabrasion compounds in terms of improvement in appearance and DSR, HCl was found clinically better compared to H3 PO4; however, the difference was nonsignificant between the two for all the severities of fluorosis. Therefore, both the compounds can be effectively used for microabrasion. However, care should be taken while using HCl, being it more corrosive. Sinha et al. found H3 PO4 clinically superior to HCl; however, the difference was again nonsignificant.
The time taken and number of applications required for the completion of microabrasion treatment were much less for HCl-pumice than H3 PO4-pumice for all severities of fluorosis, as also found by other authors in the literature. The time and number of applications increased with increase in the degree of severity of dental fluorosis with both the compounds. This could be attributed to the fact that larger surface area and depth of enamel are involved with the increasing degree of severity of fluorosis.
Meireles et al. and Mendes et al., observed posttreatment rougher enamel with H3 PO4 compared to HCl due to lesser and selective decalcification or conditioning of enamel surface, being less corrosive, thereby leaving more irregular and granular postoperative enamel surface. They also observed deeper and larger area of demineralization with HCl than H3 PO4, the possible reason for less time and number of applications required with this compound in the present study also.
The amount of enamel structure lost during microabrasion depends not only on total time and number of applications but also on the amount of pressure applied onto the tooth for application, the concentration, and corrosive potential of the compounds. Therefore, care was taken that the least amount of force was applied during the procedure in the present study.
The other advantage of microabrasion technique is that it not only removes the stains but also leaves the highly polished and densely compacted outer prismless enamel surface layer that reflects and refracts the light in such a way that mild imperfections in the underlying layers are camouflaged with better appearance in esthetics. This optical effect increases in the presence of saliva wetting the tooth surface and remineralization of the superficial enamel layer with saliva minerals and the use of topical fluoride postoperatively. The same was experienced by Price et al., Croll, and Donly et al.,, It was also taken care in the present study that all the photographs and other observations were done after an hour postoperatively in wet conditions as both the compounds used for microabrasion caused dehydration in the presence of absolute isolation; however, at the same time, excess moisture was blotted so that it did not interfere in the assessment of results. More dehydration occurred with more amount of time and number of applications required for completion of treatment.
Despite the satisfactory esthetics, microabrasion technique results in some loss of enamel structure, and thereby causing a change in color of tooth toward more yellowish appearance with an increase in number or time of applications of both the microabrasive compounds for moderate and severe fluorosis groups. This was because of the thinning of enamel letting more evident yellowish appearance of underlying dentin. Yellowish postoperative appearance was seen more with H3PO4 cases than with HCl-treated cases. Therefore, for cases with moderate and severe fluorosis, 18% HCl-pumice can be preferred to reduce the total time and number of applications, thereby reducing the amount of enamel loss and hence yellowish discoloration. This was in accordance with the results of Bassir and Bagheri. Some authors have recommended in-office bleaching after microabrasion for the correction of yellowish appearance. Others have suggested waiting for a certain period before going for bleaching to allow complete surface remineralization with postoperative topical fluoride application and saliva that enhances enamel optical characteristics.
The chances of possible failures with microabrasion were explained to the parents preoperatively, and the failed cases were further treated with resin infiltration and composite veneering.
The posttreatment satisfactory parent–patient response for most of the cases indicated that microabrasion technique using HCl-pumice and H3 PO4-pumice could improve their level of confidence, personality, and relationship with peers and society, besides the esthetics.
Recurrence or increase in the degree of stain or reduction in esthetic appearance was not observed after 3 months of evaluation in all the patients who have shown the various amount of improvement and stain removal in the present study. Therefore, it was suggested that the microabrasion technique is a stable esthetic treatment modality. Various other authors also claimed that microabrasion provided immediate and permanent results with unrecognizable or insignificant enamel loss.,,
Microabrasion should be chosen as the first line of treatment for all the severities of fluorosis. Both the compounds, HCl-pumice and H3 PO4-Pumice could be used for all the severities; however, HCl-pumice should be preferred for all the severities of fluorosis to decrease the time and number of applications required, avoid any postoperative sensitivity, and the amount of enamel lost during the procedure.
| Conclusion|| |
18% HCl with pumice and 37% phosphoric acid with pumice, both can be used for microabrasion for all the severities of dental fluorosis. The time and number of applications using HCl was lesser and hence caused less loss of enamel; therefore, it should be preferred over H3 PO4 for all severities of fluorosis. The parents and patients were satisfied with the results of both the compounds in cases which showed any degree of improvement in the appearance of involved teeth.
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Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3], [Table 4], [Table 5]