Precision and Practicality: A Novel Cellulose Gum-Based Indirect Bonding Protocol for Orthodontic Bracket Placement

This study presents an innovative indirect bonding (IDB) protocol that utilizes a cellulose gum-based denture adhesive for precise orthodontic bracket placement. The aim of this study was to evaluate the efficacy of a cost-effective IDB protocol using a cellulose gum-based denture adhesive as a temporary cast adherent. The objectives included assessing bracket transfer accuracy via digital superimposition, laboratory efficiency, and adhesive remnant index (ARI) scores.

This prospective study was conducted at the Department of Orthodontics, Government Dental College and Hospital, Kadapa, India, with ethical approval and informed consent. Working casts were prepared, and McLaughlin, Bennett, Trevisi (MBT) prescription brackets (n = 20) were aligned using pencil markings and an MBT height gauge. Dentofit R adhesive (ICPA Health Products Ltd.) was applied to bracket bases, activated by a three-second water mist, and stabilized for five minutes. Light-body polyvinyl siloxane (Zhermack Elite HD+) was used for gingival block-out, followed by thermoforming 1.0-mm soft thermoplastic sheets (Leone S.p.A.) using a vacuum/pressure thermoformer. Trays were immersed in water for five minutes to dissolve the adhesive, and the brackets were cleaned for intraoral bonding. Transfer accuracy was assessed by digitizing casts (T1) and intraoral arches (T2) using an intraoral scanner (Runyes R), with deviations measured using the MeshLab software at four bracket wing points. The laboratory cleanup time, bracket transfer accuracy, and ARI scores were evaluated. Statistical analyses were performed using paired t-tests, analysis of variance (ANOVA; one-way, two-way, and three-way), and Wilcoxon signed-rank tests (p < 0.05).

Cervical wings showed greater mean deviation (0.45 ± 0.53 mm) than incisal wings (0.24 ± 0.18 mm) (p = 0.02), with no significant differences in horizontal versus vertical deviations (p = 0.172) or mesial versus distal sides (p = 0.766). The overall deviation was clinically acceptable (p = 0.333; mean difference 0.04 mm from the 0.3 mm threshold). The median ARI score was 0, indicating the absence of adhesive remnants. The cleanup averaged 20 minutes per arch.

The cellulose gum-based IDB protocol offered precise, cost-effective bracket placement with efficient cleanup and is suitable for resource-limited settings, although cervical wing accuracy requires further optimization.