|Year : 2020 | Volume
| Issue : 4 | Page : 192-197
A full coronal restoration using a contralateral maxillary primary first molar stainless steel crown on mandibular primary first molar: An In vivo study
Kinjal A Chavda, Megha C Patel, Rohan K Bhatt
Department of Peadiatric and Preventive Denristry, Karnavati School of Dentistry, Gandhinagar, Gujarat, India
|Date of Submission||20-Jun-2020|
|Date of Acceptance||30-Jul-2020|
|Date of Web Publication||13-Oct-2020|
Kinjal A Chavda
A/907, Karnavati School of Dentistry, Uvarsad, Gandhinagar, Gujarat - 382 422
Source of Support: None, Conflict of Interest: None
Context: Stainless steel crowns (SSCs) are considered most successful and widely used full coronal restorations for primary molars. Choice of an appropriate SSC, with regard to size of the crown, proximal fit, and marginal adaptation has always been challenging for pedodontist. Contralateral crown is one such unique approach to restore the primary molars with anatomical variation as well as in cases of loss of arch length due to mesiodistal (MD) caries. Aims: This study aims to evaluate the clinical outcome of a contralateral SSC on primary first molars. Objectives: The objective is to assess the longevity of restoration, gingival health of the tooth, and tooth wear of opposing tooth in concern. Subjects and Methods: A total of 60 children between the age group of 3–8 years participated in the study. SSC was placed using MD width of maxillary primary first molar on mandibular primary first molar using Mink and Bennett technique. Regular follow-up was scheduled at 3, 6, and 12 months' interval. Statistical Analysis: Statistical analysis was performed in Excel format using SPSS version 18. The level of statistical significance was set at P < 0.05. Results: The success rate using contralateral SSC on primary first molar during 12 months was 93.3%. Gingival health at baseline, 3, 6, and 12 months' interval showed clinically significant difference (P = 0.1) whereas the tooth wear showed statistically significant difference at 12 months' interval (P < 0.001). Conclusions: The approach of placing contralateral SSC on primary first molar proved to be successful and has no harmful effect on gingiva provided that good oral hygiene was maintained.
Keywords: Contralateral, primary first molar, stainless steel crowns
|How to cite this article:|
Chavda KA, Patel MC, Bhatt RK. A full coronal restoration using a contralateral maxillary primary first molar stainless steel crown on mandibular primary first molar: An In vivo study. Indian J Dent Sci 2020;12:192-7
|How to cite this URL:|
Chavda KA, Patel MC, Bhatt RK. A full coronal restoration using a contralateral maxillary primary first molar stainless steel crown on mandibular primary first molar: An In vivo study. Indian J Dent Sci [serial online] 2020 [cited 2021 May 6];12:192-7. Available from: http://www.ijds.in/text.asp?2020/12/4/192/298037
| Introduction|| |
Stainless steel crowns (SSCs) are considered the most preferred choice for the repair of severely carious, malformed, or fractured primary molars in primary dentition, since Humphrey first used them in pediatric patients in 1950. Ever since it has been most effective and efficient method of tooth restoration in pediatric dentistry. Preformed metal crowns for primary molar teeth was first described by Engle.
Preformed metal crowns have been indicated for the restoration of primary and permanent teeth with extensive caries, cervical decalcification, and/or developmental defects (e.g., hypoplasia and hypocalcification), when failure of other available restorative materials is likely (e.g., interproximal caries extending beyond line angles, patients with bruxism), following pulpotomy or pulpectomy, for restoring a primary tooth that is to be used as an abutment for a space maintainer, for the intermediate restoration of fractured teeth, for definitive restorative treatment for high caries-risk children, and used more frequently in patients whose treatment is performed under sedation or general anesthesia. SSC is the most preferred material of choice and has long-term success rate for restoring Class II lesions in deciduous molars. Over the years, numerous clinical studies including the longitudinal studies by Messer and Levering have demonstrated the superiority of SSCs in restoring primary molars with multi-surface involvement.
SSCs are extremely durable, relatively inexpensive, subject to minimal technique sensitivity during placement and offers the advantage of full coronal coverage. Inadequate marginal adaptation and marginal discrepancy have a negative effect on the longevity and success of SSCs. It is, therefore, important to assess the factors that influence the adaptation and fit of the crown.
Afshar et al. compared the primary molar crown dimensions with SSCs in the Iranian children and result showed that primary molars have variations in size and the primary first molar crown has shown the widest variations in dimensions (primary second molar had the smallest variations). Since SSCs are selected based on their ideal Mesiodistal (MD) adaptation to the teeth (to achieve appropriate contact with the adjacent teeth), the important issue is that whether the selected SSC has adequate buccolingual (BL) adaptation to the tooth particularly at the cervical area, which is the most important site for achieving a perfect fit.
In the primary dentition system, carious lesions often develop early in the primary first molars and SSCs are considered a suitable restoration for these teeth. In addition, relatively early eruption of the primary first molars and not restoring them in time can cause a possible reduction in MD dimensions and consequently, loss of space. Reduction in the MD dimension of the crown becomes necessary, especially where mesial drift (often due to caries) has resulted in loss of arch length. Where mesial drift has occured in the lower arch it may be possible to use a SSC from the contralteral upper tooth (e.g., Upper Left D crown for Lower Right D) as these SSC forms have a shorter MD dimension. Other forms of modification, including vertically slicing one aspect of the crown and spot-welding additional segments of stainless steel band to increase the perimeter or extend the length have been described, but their efficacy remains largely untested. When the space loss occurs distal to the mandibular primary first molar in an amount of a few millimeters, it is not possible to select an appropriate size crown due to the loss of MD dimension. In this case, selection of primary maxillary first molar crown of the opposite side is recommended.
Enamel wear caused by dental materials is an important factor that should be contemplated during material selection in clinical practice. Seghi et al. stated that dental restorative materials should not increase the wear rate for the opposing enamel surface and should manifest a wear rate similar to that for enamel. Gingivitis is the predominant form of periodontal disease in children and adolescents, and it consists of a nonspecific inflammation of the marginal gingiva. It has been reported that gingivitis often occurs around primary teeth restored with SSCs.
Therefore, the aim of the study was to evaluate the clinical outcome of contralateral maxillary primary first molar SSC placed on mandibular primary first molar. The objective of the present study was to assess the longevity of restoration, gingival health of the tooth, and tooth wear of opposing tooth in concern, as no study has been conducted till date as per the best of our knowledge.
| Subjects and Methods|| |
The present study was conducted in the Department of Pedodontics and Preventive Dentistry at Karnavati School of Dentistry, Gandhinagar. The study design was reviewed and approved by Institutional Ethical Committee with reference no. (KSDEC/15-16/Apr-02). Thisin vivo interventional study was carried out among 60 children within the age group of 3–8 years. All patients were examined by the principal investigator. Patients were included only after the parents/legal guardian signed the consent form.
- Loss of MD dimension
- Teeth requiring pulp therapy or infection is pulpally involved
- Teeth requiring full coronal restoration
- Teeth to be treated with Class II restoration
- Teeth requiring multisurface restoration
- Presence of flush terminal/mesial step in primary molar relationship.
- Presence of occlusal caries not involving proximal surfaces
- Presence of tooth wear (abrasion/attrition) on opposing teeth or absence of those teeth
- Longevity of tooth in quadrant
- Absence of opposing tooth
- Teeth which has poor prognosis
- Teeth which has occlusal discrepancies
- Patients with habit of bruxism
- Patients with any systemic disorder.
The method of placement of contralateral maxillary primary first molar SSC is shown in [Table 1]. Before selecting a SSC for mandibular primary first molar, preoperative occlusion was evaluated. [Figure 1] shows preoperative occlusal view. Prior to tooth preparation occlusal bite was registered using bite registration wax. For each patient crown size selection was done using Randall's trial and error method. Local anesthesia was achieved using lidocaine hydrochloride 2% with epinephrine 1:100,000. Following Local Anesthesia (LA) administration, a split dam technique was used for isolation [Figure 2]. If tooth required pulp therapy, it was performed at the same visit. Tooth preparation was done using Mink and Bennet technique for SSC placement. Reduction of the occlusal surface was done by about 1.0–1.5 mm using a flame shape or pear shape bur at high speed to produce uniform occlusal reduction. The interproximal slicing mesially and distally was done with the help of 169 L bur or taper fissure bur. The reduction should allow the probe to pass through contact area. All line angles and sharp corners of the preparation were rounded off with the help of finishing burs. Tooth preparation was modified to adapt the morphology of primary maxillary first molar. For better fit of the crown occlusal one third of buccal surface was beveled. Following preparation, crowns [3M™ ESPE™, USA SSCs] were tried in for appropriate sizing. Cementation of contralateral maxillary primary first molar SSC was done using Type 1 GIC (3M™ ESPE™) [Figure 3]. After cementation of contralateral maxillary primary first molar SSC postoperative occlusion was checked and intraoral periapical (IOPA) radiograph was taken [Figure 4] and [Figure 5]. All procedures, including tooth preparation, selection, adjustment and cementation of crowns, were performed by a single operator. In addition, the mixing of cement was performed according to the manufacturer's instructions.
|Table 1: The method of placing contralateral maxillary primary first molar stainless steel crown on mandibular primary first molar|
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|Figure 5: Intraoral periapical radiograph showing contralateral maxillary stainless steel crown|
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Follow-up and evaluation
Each patient was evaluated and followed up at every 3, 6, and 12 months for restoration longevity, gingival health, and tooth wear of opposing tooth in concern. For clinical outcome of contralateral maxillary primary first molar crowns, restoration success, gingival health, and tooth wear of opposing tooth in concern were checked [Table 2]. Restoration success was checked using grading system criteria for SSC. For the evaluation of gingival health, a blunt periodontal probe (Double-ended Williams probe) was used. According to According to the Loe and Silness gingival index, gimgival score was given. To check the tooth wear on opposite tooth in concern, Smith and Knight tooth wear index was used.
|Table 2: Criteria for clinical evaluation of contralateral stainless steel crown|
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Statistical analysis was performed using the Statistical Package for Social Sciences (SPSS version 18.0 for Windows). The data obtained were subjected to statistical analysis at a 0.05 level of significance. Changes in gingival health at 3, 6, and 12 months were evaluated using paired sample t- tests. Chi-square analysis for proportions was applied to test for differences in restoration failure and tooth wear indices at 3, 6, and 12 months.
| Results|| |
A total of 60 children received contralateral primary maxillary first molar SSCs which were followed up for an average period of 12 months. Routine IOPA radiographs were taken after the insertion of SSC. [Graph 1] illustrates the outcome of placing contralateral maxillary primary first molar SSC on mandibular primary first molar. During the study, 93.3% of SSC were graded to be successful, while 6.7% SSC failure was noticed at 12 months. At 3 and 6 months evaluation, two observed failures of placing contralateral maxillary primary first molars on mandibular primary first molars were due to decementation of crown which were successfully treated with re-cementation on follow-up visits. Decementation of crowns could be due to reduced crown structure. Two crowns failed due to secondary caries at 12 months recall [Graph 1]. On radiographic examination, it was found that these teeth needed further treatment hence, those were successfully treated. At 3, 6, and 12 months' follow-up, restoration failure noticed was 6.7%. However, 93.3% success rate was seen after placing contralateral maxillary primary first molar crown which was clinically significant (P < 0.001).
Tooth wear of opposing tooth in concerned was checked using Smith and Knight tooth wear index. Tooth wear after placing contralateral maxillary primary SSCs was checked clinically after 3, 6, and 12 months, respectively. [Table 3] shows the outcome of SSC and tooth wear results at 3, 6, and 12 months' follow-up. There was no change found in enamel surface characteristics at 3 months' follow-up. Mild tooth wear was seen in 3.3% of cases whereas 96.7% of cases did not show any loss of enamel surface characteristics or loss of contour at 12 months' follow-up (P < 0.001).
|Table 3: Outcome of stainless steel crown and toothwear results at 3, 6 and 12 months follow up|
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[Graph 2] illustrates the gingival health at 3, 6, and 12 months' follow-up. Mean gingival health (MGH) score was significantly reduced at 12 months' follow-up period (P = 0.1) [Table 4]. From baseline to 12 months, there was clinically significant improvement in gingival health.
| Discussion|| |
Since the introduction of SSCs by Humphrey in 1950, they have been extensively used for the restoration of primary and permanent posterior teeth. No other restoration has the ease of use, durability, and reliability of these full coverage crowns for the primary teeth. Variations in teeth size in different races do not usually pose a significant problem considering that SSCs are manufactured in different sizes. However, since SSCs are selected based on their ideal MD adaptation to the teeth (to achieve appropriate contact with the adjacent teeth), if adequate attention is not paid, such misfit in the MD dimension can cause the over-contour in distal and lead to ectopic eruption of the permanent first molar tooth. If a smaller size SSC is selected to achieve MD fit, the buccal and lingual surfaces will require excess preparations above the standard and classic limit.
From the occlusal view, maxillary primary first molars are rounder than mandibular primary first molars, which can be described as roughly rhomboidal with curved sides and corners. In the rare instance, a mandibular primary first molar is rounder than normal or due to space loss as consequence of caries the BL dimension is more as compared to MD. In such cases, a clinician can substitute a contralateral/opposing arch SSC form to fit the lower molar more ideally. For example, a crown designated as upper left size 6 might fit a mandibular right primary first molar better than lower right 6 (LR 6) or even the LR5 or LR7. It is not common for contralateral/opposing arch crown to be required in clinical pediatric dentistry as manufacturers of SSCs offer a variety of a primary molar crown sizes, and most often suitable size can be selected.
In the present study, the tooth wear of opposing tooth in concern found was not significant clinically. A slight tooth wear in natural dentition is considered normal. The abrasivities of primary and permanent teeth differ due to their different enamel strengths, morphological factors, such as, enamel and dentin thickness, and the different biting forces of adults and infants. In a comparative study conducted by Nose on molar enamels of primary and permanent teeth, the Vickers hardness number (HV) of primary teeth was 106 (HV) and that of permanent teeth was 126 (HV), which suggests poorer wear resistance of primary teeth. Nelson et al. reported primary tooth enamel was thinner than permanent tooth enamel, and thus, more prone to wear. If restorative dental materials have different wear properties compared to the natural teeth, they can affect the wear rate of antagonist natural teeth. Therefore, wear occurring between enamel and dental restorations is an important factor that should always be considered in the selection of restorative materials in clinical practice.
In the present study, mean gingival health score was significantly higher at 3 and 6 months' follow-up which was statistically reduced at 12 months' follow-up. Failure of crowns could be due to poor oral hygiene and improper food habits. At each follow-up visit, oral hygiene measures were reinforced to patient hence, gingival health at 12 months' follow-up was significantly improved. It is preferable to keep the restoration margins coronal to the free gingival margin. Subgingival margin placement is often unavoidable for primary teeth. Retention of full coverage crowns for primary teeth comes mainly from subgingival placement. The degree of gingival inflammation is directly related to the location of crown margin. Newcomb stated that as the margin goes from supra to a subgingival position, the gingival health deteriorates. In the present study, MGH score was reduced at 6 and 12 months' interval which was clinically acceptable.
However, a study with a longer follow-up period is recommended.
It is acknowledged that the present study had the following limitations:
- All outcome showed in the present study should be elucidated as descriptive and interim and not as certain due to constrained sample size
- A study with a longer follow-up period is recommended for better evaluation of contralateral crowns
- In addition, considering the impact of buccal and lingual reduction on retention of crowns placed on mesiodistally reduced primary mandibular first molars, it is recommended that a similar study be conducted to investigate the effect of reduction on crown retention.
| Conclusions|| |
- Placing contralateral maxillary primary first molar SSC on mandibular primary first molar proved to be successful
- This technique is specifically recommended for primary mandibular first molars with reduced MD dimensions and greater anatomic variation
- The present study showed contralateral crowns had no harmful effect on gingiva provided good oral hygiene was maintained
- In the present study, tooth wear of opposing tooth in concern found was not significant clinically.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Figure 1], [Figure 2], [Figure 3], [Figure 4], [Figure 5]
[Table 1], [Table 2], [Table 3], [Table 4]