“Evaluation Of Innovative 3D Printed Space Maintainer Versus Conventional One”

Abstract

This study compared B&L SM and 3D printed SM, with regards to their clinical performance; and the gingival health of their abutment teeth, as well as; patient satisfaction towards both types of SMs. The study sample comprised 24 children aged (6-8) years, who were admitted to the Pediatric Dentistry and Dental Public Health Clinic, Faculty of Dentistry, Ain-shams University, with bilateral mandibular first primary molars indicated for extraction mainly due to gross coronal destruction, periapical involvement and/or advanced root resorption. The study was carried out in a split mouth design where B&L SM was placed in one quadrant, while 3D printed SM was bonded to abutment teeth in the contralateral quadrant. Both appliances were evaluated over a period of 6 months. For 3D printed SM group, intraoral scans of mandibular arch were obtained and the appliance was innovatively designed using an appliance designer software. The SM bonded to both primary abutment teeth with resin cement. 3D printed SM showed higher success rate (75%) than B&L SM (62.5%), however this difference was not statistically significant. The most common cause of B&L SM failure was cement loss while the most common cause of 3D printed SM failure was due to debonding that occurred at the enamel-cement interface. The (PI) and the (GI) were scored from 3 sites, the banded abutment of B&L SM, the bonded molar abutment of the 3D printed SM and a sound molar in the opposing arch as a control tooth, preoperatively and after a 6 months follow-up. After 6 months; B&L abutments showed a statistically significant highest mean PI and GI scores. 3D printed SM abutments showed a statistically significant lower mean score. Control teeth however; showed the lowest statistically significant mean PI score. 3D printed SMs showed statistically significant higher patient satisfaction than metal B&L SMs. In Vivo Part: This study part was designed to evaluate the fracture resistance and ease of debonding of conventional B&L SM compared to 3D printed SM. For the fracture resistance test all samples were loaded in a universal testing machine until fracture occurred. Data were collected and presented as mean. It was found that 3D printed SM recorded higher fracture resistance than B&L SM. Shear bond strength test was used to evaluate the ease of debonding of both types of cemented bands of the SMs. 3D printed band cemented with resin cement recorded higher bond strength than conventional metal band cemented with glass ionomer cement.