Comparative Evaluation of Flexural Strength and Surface Microhardness of Temporary Dental Disocclusion Materials with and Without Thermocycling - An in Vitro Study

Introduction

In Orthodontics, there are several indications for bite opening. Fixed appliances, though small, can interfere with occlusion and function, potentially causing tooth abrasion or bracket debonding. To prevent occlusal interferences from damaging mandibular brackets, temporary dental disocclusion is often necessary. This facilitates tooth movement that may otherwise be restricted by deep bites, telescopic bites, buccal non-occlusions, or crossbites.¹

Orthodontic bite raisers are specially designed surfaces placed anteriorly or posteriorly to create a contact plane that prevents full jaw closure.² While removable bite plates require patient compliance and laboratory fabrication, many orthodontists now prefer directly bonded materials like composite resins and glass ionomers due to their ease of use and improved bonding techniques. These bonded attachments are actually commonly known as “bite turbos.”³

A wide range of composite materials is available for both direct and indirect bonding, valued for their favorable physical and mechanical properties. These composites typically consist of an organic polymatrix, inorganic fillers, and a silane coupling agent. Their mechanical behavior is closely tied to composition and also microstructure. Nanofilled composites, which contain uniformly dispersed nanosized particles, offer better protection to the matrix due to reduced inter particle spacing. As a result, they exhibit enhanced wear resistance and microhardness.⁴ Orthodontic composites like Orthobite and Orthocem also offer additional advantages such as pigmentation and fluorescence, which facilitate easy identification and removal of bite turbos after treatment without causing iatrogenic damage.⁵