Year : 2009 | Volume
: 27 | Issue : 3 | Page : 158--163
A comparison of enameloplasty sealant technique with conventional sealant technique: A scanning electron microscope study
R Khanna1, RK Pandey1, N Singh2, A Agarwal3,
1 Department of Pedodontics, Faculty of Dental Sciences, Chhatrapati Sahuji Maharaj Medical University, Lucknow (UP), India
2 Department of Pedodontics, UP Dental College and Research Centre, Lucknow (UP), India
3 Department of Pedodontics, Subharti Dental College, Meerut (UP), India
Department of Pedodontics, Faculty of Dental Sciences, Chhatrapati Sahuji Maharaj Medical University, Lucknow (UP)
Context: An accurate diagnosis of occlusal surface of permanent posterior teeth for the presence of caries is a challenge to the clinician, when using traditional explorer. This dilemma of hidden caries has led to invasively opening of the fissure before sealant placement. Enameloplasty is one such invasive procedure that has been implicated in the successful application of pit and fissure sealants. Aims: The present study aims at evaluating the fissure micromorphology and sealant penetration under scanning electron microscope both with conventional sealant technique and enameloplasty sealant technique. Settings and Design: The study comprised of extracted human posterior teeth subjected to enameloplasty of the fissures in the study groups as compared to unprepared fissures in the control groups. Materials and Methods: The enameloplasty was performed with the help of specially designed Fissurotomy bur. The sealant used was Clinpro from 3M. All the samples were prepared for examination under scanning electron microscope. Statistical Analysis: A student «SQ»t«SQ» test was performed to compare the study and the control groups. Results: (i) The surface area available for sealant placement on the occlusal surface was significantly increased following enameloplasty. (ii) Fissure width following enameloplasty was significantly increased. (iii) Extent of sealant penetration was significantly greater with enameloplasty sealant technique as compared to conventional sealant. Conclusion: Enameloplasty sealant technique can be preferred to conventional sealant technique for improving adhesion, adaptation and penetration of the sealant within the fissure system.
|How to cite this article:|
Khanna R, Pandey R K, Singh N, Agarwal A. A comparison of enameloplasty sealant technique with conventional sealant technique: A scanning electron microscope study.J Indian Soc Pedod Prev Dent 2009;27:158-163
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Khanna R, Pandey R K, Singh N, Agarwal A. A comparison of enameloplasty sealant technique with conventional sealant technique: A scanning electron microscope study. J Indian Soc Pedod Prev Dent [serial online] 2009 [cited 2019 Dec 13 ];27:158-163
Available from: http://www.jisppd.com/text.asp?2009/27/3/158/57096
The morphological complexity of the pit and fissure system of human posterior teeth, account for their vulnerability to development of dental caries. Ripa (1973)  observed that although the occlusal surfaces represented only 12.5% of the total surfaces of the permanent dentition, they accounted for almost 50% of dental caries in school children. The morphology of these pits and fissures tend to mask the size and extent of the lesion during routine examination. Nagono (1960)  reported that 42% of the fissures have narrow occlusal openings that prevent entry of the explorer into the lesion. Histological cross-section has confirmed a ratio of 1 : 4 (25%) accuracy in diagnosing decay on the occlusal surface using the traditional explorer (Al-Sehaibany, 1996)  This diagnostic challenge often leads to sealing of doubtful fissures and unhampered progression of hidden caries. There is widespread disagreement amongst the professionals between invasively opening the fissure before sealant placement, and non-invasive sealant application. One of the invasive alternatives is 'enameloplasty' or 'reshaping of enamel', carried out with the help of suitable rotary cutting instruments. The present study aims at evaluating the fissure micromorphology and sealant penetration under scanning electron microscope both with conventional sealant technique and enameloplasty sealant technique.
Materials and Methods
The extracted human teeth that served as samples in the present study were expected to meet the following requirements:
The teeth had intact occlusal surfaces.The occlusal surfaces presented deep, narrow occlusal pit and fissure system that did not allow proper clinical inspection of caries.
A total of 16 human permanent molars selected for the present study were stored in 10% formalin solution for 24 h and then embedded in a synthetic resin cube of self-curing acrylic resin (DPI-RR). The samples were then cleaned with aqueous slurry of fine flour of pumice with a fine bristle brush, in a slow-speed handpiece (NAC-EC, NSK), rinsed with water jet and dried with oil-free compressed air. The sample teeth were distributed at random into four groups of four teeth each.
Group 1: No Enameloplasty, No Sealant: The specimens in this group were subjected to pumice prophylaxis, rinsing, drying.
Group 2: No Enameloplasty, Sealant Application: The specimens were prepared similar to group 1, but followed by sealant application.
Group 3: Enameloplasty, but no Sealant Application: The specimens were subjected to pumice prophylaxis, rinsing, drying followed by fissure enameloplasty with bur.
Group 4: Enameloplasty followed by Sealant Application: The specimens were prepared similar to that in Group 3, followed by sealant application.
The enameloplasty procedure
Enameloplasty was performed in specimens selected in Groups 3 and 4. Fissures were slightly opened with the help of Fissurotomy; Micro STF bur (SS White, Lakewood) in a high-speed air turbine, handpiece (Pana-air, NSK), to approximately the dimensions corresponding to the diameter and length of head of the bur.
Specimens in Groups 2 and 4 were prepared for sealant application. After pumice prophylaxis, rinsing and drying, the occlusal surfaces of the specimens were treated with 37% phosphoric acid gel (Dentsply) for 30 s with the help of a disposable brush, rinsed with distilled water for 10 s, and then dried with oil-free compressed air. The etched surfaces of enamel at the entrance of each fissure system were examined to assure the frosted appearance. The sealant (Clinpro, 3M) was then applied to the etched fissure systems following manufacturer's instructions. To prevent voids and air entrapment, the sealant was gently teased through the fissure with the 0.5 mm tip of a periodontal probe (API) and was then polymerized using a light-cure unit (Optilight LD III, Gnatus) for 40 s.
Preparation of specimens for examination under Scanning Electron Microscope
Groups 1 and 3: Specimens in these groups were prepared in the following manner. First, the roots were cut from the crowns using a water-cooled diamond blade (Microdont). All specimens were then kept in 90% alcohol in a glass beaker and then placed in ultrasonic vibrator (Bransonic 221) for 5 min. The specimens were then dried under white light, and fixed onto aluminium stubs with the help of adhesive films. A drop of electro-conductive silver paint (Dotite-EMS) was placed on two diametric opposite positions of the specimen fixed on the stub, caring not to cover the area to be examined. The specimens were then coated with a conductive layer of gold-palladium alloy with the help of a sputtering device (Poloran). They were then examined under the scanning electron microscope LEO 430. The observations were recorded on Polaroid films.
These observations allowed comparison of surface area of the fissure system, both with and without enameloplasty procedure. Surface area analysis was performed on a Gateway 2000 computer using the free UTHSCSA Image Tool program (developed at Department of Dental Diagnostic Science, University of Texas Health Science Centre, San Antonio, Texas) and available from Internet by anonymous FTP from ftp://maxrad6.uthscsa.edu.
Following recording on Polaroid films, the samples were slit longitudinally in a bucco-lingual (or mesio-distal) direction with a water-cooled diamond blade to facilitate fracture of the crowns through the fissures, providing sections of thickness ranging from 1 to 1.5 mm. The specimens were then remounted on aluminium stubs as described, and coated for re-examination by SEM, and the observations were recorded on Polaroid films. These observations allowed assessment of the changes in width of opening entrance of the fissure and at other levels of the fissure, when enameloplasty was performed. Fissure width at three levels of the fissure in each specimen (opening entrance, middle and base) was measured on a Gateway 2000 computer using the free UTHSCSA Image Tool program (developed at Department of Dental Diagnostic Science, University of Texas Health Science Centre, San Antonio, Texas) and available from Internet by anonymous FTP from ftp://maxrad6.uthscsa.edu .
Groups 2 and 4: Specimens in these groups were also sectioned longitudinally in a bucco-lingual (or mesio-distal) direction by a water-cooled diamond blade, of thickness as in Groups 1 and 3. The specimen sections were fixed onto aluminium stubs and prepared for examination under SEM as in Groups 1 and 3. The observations were recorded on Polaroid films.
These observations permitted the examination of the extent to which the sealant penetrated into the pits and fissures, both with and without performing enameloplasty prior to sealant application. Percentage of sealant penetration was calculated at three points selected randomly in each specimen, on a Gateway 2000 computer using the free UTHSCSA Image Tool program (developed at Department of Dental Diagnostic Science, University of Texas Health Science Centre, San Antonio, Texas) and available from Internet by anonymous FTP from ftp://maxrad6.uthscsa.edu
UTHSCSA Image Tool Program
It is a free image processing and analysis program for Microsoft Windows'95™ or Windows NT™. It has been written in Borland's C++ version 5.02. It has been developed at University of Texas Health Science Centre, San Antonio, Texas, by C. Donald Wilcox, S. Brent Dove, W. Doss McDavid and David B. Geer. Image analysis functions of this program include dimensional (area, distance, angle, perimeter) and gray scale measurements (point, line and area histogram statistics). Information related to the program can be accessed by world wide web at http://ddsdx.uthscsa.edu/
(a) Occlusal view: The area occupied by the fissure system on the untreated occlusal surfaces in Groups 1 and 3 was calculated with the UTHSCSA Image Tool Program. The mean surface area observed in Group 1 [Figure 1] was 2.24 ± 0.48 mm 2 and in Group 3 [Figure 2] was 23.90 ± 3.11 mm 2.
Comparison of surface area of Groups 1 and 3 [Figure 3] revealed a mean increase of 21.66 ± 2.65 in Group 3 from that of Group 1. On comparing, statistically significant difference in surface areas between two groups was seen (p t' = 16.342.
(b) Longitudinal view: In longitudinal sections of specimens of Groups 1 and 3, the width of the fissure systems was calculated at three different levels of the fissure: (a) opening entrance, (b) middle, (c) base of the fissure, with the help of UTHSCSA Image Tool Program [Table 1][Figure 4] and [Figure 5] . Mean change in width at opening/entrance was 0.900 ± 0.313 mm, which was significant statistically (p = 0.010). Mean change in width at middle of fissure was 0.395 ± 0.097 mm, which was also significant statistically (p = 0.004). Mean change in fissure width at the base of fissure was 0.070 ± 0.045 mm. On statistical comparison this change was found to be statistically non-significant (p = 0.054). Thus it was found that the fissure width increased significantly at the opening entrance and middle of the fissure, when subjected to enameloplasty. The change in fissure width at the base of the fissure was however not significant [Figure 6]
In Group 2, sealant penetration in the untreated fissure system was very shallow, sometimes limited to the cuspal inclines. [Figure 7]. The mean sealant penetration was 60.059 ± 15.629%. Similar observation in Group 4 showed that mechanically treated occlusal fissures allowed much deeper penetration of sealant and fewer voids and gaps, as compared to Group 2 [Figure 8]. The percentage of depth of fissure occupied by the sealant was 92.351 ± 6.189%. The comparison of mean percentage penetration of Groups 2 and 4 showed a mean difference of 32.292 ± 18.720 [Figure 9] between Groups 2 and 4, thus indicating significantly higher sealant penetration in Group 4 as compared to Group 2 (p  De Craene et al. (1988)  researched the invasive technique of pit and fissure sealant placement to establish the presence of caries on the occlusal surface. In 1996, DoRego and Araujo  evaluated fluoride containing sealants placed with an invasive technique. According to their study, as determination of caries activity in fissures was doubtful, an exploratory technique or 'excisional biopsy' offered the best access, and best technique for maximum retention, conservation of healthy tooth structure, following certain removal of decay. They stated that excisional bur remodeled the anatomy of the fissure, facilitating access, acid-etching and bonding of resin into the cavity preparation.
The present study, was thus, designed on the basis of the advantages that the invasive technique of sealant placement conferred, according to the literature. In the present study, the fissure micromorphology was studied under SEM and it was found that there was an increase in area of fissure system when enameloplasty was performed. These findings were confirmed by the studies of Garcia-Godoy and de Araujo (1994)  and Xalabarde, Garcia-Godoy (1996).  These studies stated that increase in surface area provided a thicker layer of sealant rather than a thin layer resulting after conventional sealant application, and this thicker layer provided more wear resistance. According to Tadokoro et al. (1982),  the sealant easily penetrates the enlarged fissure and adheres to the walls resulting in better retention. Another explanation for better retention was given by Shapiro et al. (1984),  who found that mechanical preparation widened and deepened the fissure by eliminating organic material and plaque resulting in better retention.
The effects of enameloplasty on fissure width and sealant penetration were found to be significant. In the present study it was found that fissure opening by enameloplasty leads to increased fissure widths at different levels resulting in better penetrativity of the sealant. Powell (1978)  has concluded from his study that 334 out of 390 wide fissures examined were completely filled by the sealant material. In contrast, only 28 of the 650 constricted fissures examined were completely filled by these resins. Sutalo et al. (1989)  has described the morphological types of fissures system in permanent human molars, their average depth and width as well as the penetration capacity of fissure in relation to the morphological type of the fissure established (V, U, Y1, Y2). They concluded that the penetration capacity of the sealant was in certain correlation to the width of fissure entrance and the fissure depth.
Previous studies demonstrated various measures to increase resin penetration. Garcia-Godoy and Gwinnett (1987)  found that even when scraped into fissures with an explorer, the gels, solutions or sealants did not penetrate beyond fissural constriction. They also found that pumice prophylaxis did not completely and consistently remove material deposits from pits and fissures. Air-polishing was also suggested by Verterhus and Raadal (1988).  The technique improved fissure cleanliness and sealant adaptation, but did not permit the sealant to reach the base of pits and fissures; perhaps due to air entrapment. Another more radical technique proposed to enhance sealant penetration was mechanically enlarging the pits and fissures with bur. La Bell et al. (1980)  demonstrated superior sealant retention with this technique. It was also found that the bur treatment removed the outermost prismless layer of enamel, described as 'coral-like' enamel by Garcia-Godoy and Gwinnett (1991),  when acid-etched enamel was evaluated under SEM. The difference in retention rates were considered to be due to differences in topography between prismless enamel and prismatic enamel. Recently, air abrasion has also been suggested as an invasive technique for fissure remodeling for sealant penetration. The problem, however, with this technique is association of a learning curve in terms of direction, cutting depth and focus of spray. Also, unlike burs, there is no tactile feedback during the preparation process.
The invasive technique is opposed by many professionals who believe that sealing fissures with hidden caries tend to reduce the viable microorganisms, eventually leading to lesion arrest (Mertz-Fairhurst et al. 1986;  Handelman et al. 1987  ). However, the observation time in these studies was limited, and the caries status of the sealed teeth was not documented precisely. Moreover, cavitated fissures may contain biofilm (Fejerskov and Kidd, 2003),  which is impossible to remove because of difficult access, thus preventing a sealant from adapting properly in the fissure.
Several burs have been used for the purpose of enameloplasty in previous studies. Traditionally used small round or flame shaped burs, though provided a conservative preparation, good explorer access, were more liable to leave undercut enamel. The Fissurotomy; Micro STF (SS White) burs used in the present study are specifically designed for recontouring the fissures and accessing decay with minimum enamel removal, are fast-cutting and conservative (George Freedman and Fay Goldstep). They are however, not indicated for treatment of larger decay. The Fissurotomy; Micro STF is especially indicated for enameloplasty procedure as its head length is 1.5 mm. The tapered shape of the bur allowed the cutting tip to encounter very few dentinal tubules at any given time and has been designed to minimize heat build-up and vibration.
The results obtained from the present study are as follows: (i) The surface area available for sealant placement on the occlusal surface is significantly increased following enameloplasty; (ii) Fissure width following enameloplasty was significantly increased; (iii) Extent of sealant penetration was significantly greater with enameloplasty sealant technique as compared to conventional sealant placement technique, with fewer voids and gaps being evident. Thus, in accordance to the results of the present study and support from the literature, enameloplasty sealant technique can be indicated for placing fissure sealants in occlusal fissures, especially with deep, narrow fissures.
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