Comparative evaluation of clinical and radiographic success after placement of preformed stainless steel and flexible esthetic crowns by various techniques in pediatric patients – A parallel group prospective randomized clinical study.

Dental caries is an infectious transmittable bacterial disease, which is characterized by a multi-factorial pathology.1 In the early childhood the caries (ECC) have effects on both dental and general health of the child.2 Oral health impacts on the quality of life of children 3, 4. However, extreme caries have a noticeable impact on the diameter of the arch.5

In order to preserve the functional integrity of primary dentition, it is important to perform different restorative treatment due to an increase in the prevalence of dental caries today.6 In all restorative procedures, there is a loss of some amount of tooth structure, these damaged teeth can be restored with various restorative materials such as resin modified glass ionomer cement, resin filled composite or resin filled composite.7 For primary molar teeth, preformed metal crown were first described by Engle8 in year 1950 and followed by Humphrey.9 Since then, crown design modifications are done, to improve morphology of crown and to simplify the fitting procedure.10 Stainless steel crowns are the first choice for restoring defects due to caries in primary dentition and the most reliable and successful form of tooth restoration is in pediatric dentistry.9 Stainless steel crown placement is easy and economical with a high success rate for preserving remaining teeth damaged by excessive preparation.11,12 Esthetic concern is reported to be the most important problem for dental restoration in a study in pediatric patients.13Accordingly, new materials have been created to replace SSCs, such as bonded strip crowns, open-faced crowns and pre-veneered SSCs.14,15 These new materials have enhanced aesthetics but have side effects such as poor gingival health and dental margin exposure due to metal presence.11 In particular pre-veneered SSC veneer resin sometimes chips and results in additional care..15,16

Today, for the restoration of the primary teeth, the dental practitioner has various options like preformed zirconia crowns for esthetic concern. Based on technical, functional and esthetic limitations, each technique is associated with the own sets of advantages and disadvantages.17, 18, 19

Alternative to these, prefabricated esthetic flexible crowns are comparatively new. Flexible crowns allow practitioner to provide aesthetics of new age crowns and easy, economical as well as conservative preparation of stainless steel crowns in addition to that  they can be corrected like SSCs and that’s the reason this study is planned

 In recent years restoring carious or fractured primary teeth with stainless steel crowns (SSC) has became more popular than ever. On the other hand the traditional operative approach of complete removal of caries is steadily losing support due to successful results with materials of high microleakage resistance.

Treatment time and pain control in asymptomatic teeth has always been a problem in children. Hall technique is a minimally invasive treatment protocol that doesn’t require local anesthesia, use of rotating devices for caries removal to restore primary teeth with SSC.

But this protocol also raised questions in the scientific community about its possible effects on the dentition and temporomandibular joint (TMJ) for causing primary occlusal contact and increasing vertical dimension.

 Preformed metal crowns (PMCs) have high success rates in restoring primary molars in children but they were not generally used by dentists, especially in developing countries due to its demand of high clinical skills with the conventional technique (CT). The biological approach, Hall technique (HT), requires less training and can be placed by less experienced dental operators including therapists. Previous studies were mainly carried out in developed countries. The aims were to investigate and compare the efficacies and cost-effectiveness of preformed stainless steel and flexible esthetic crowns

 The purpose of this study is to compare the effectiveness of the flexible esthetic crown to the conventional Stainless-Steel Crown restoration by various techniques in the treatment of primary molars with dentinal caries with or without proximal ridge intact.