The question is about Resin Bonded Fixed Partial Dentures (FPD), specifically focusing on the Maryland and Virginia styles, and which type of dental occlusion presents a contraindication for their use. Let's go through each option to determine why "Deep bite" is the correct answer.
- Understanding Resin Bonded FPD:
Resin bonded FPD, such as Maryland bridges, are types of fixed dental prostheses that are cemented to the backs of adjacent teeth and are mainly used for replacing missing teeth with minimal alteration to the adjacent teeth.
- Analysis of Occlusal Conditions:
- \(Open\ bite\): This is an occlusion where there is no vertical overlap of the anterior teeth, or there is space between the occlusal surfaces of the anterior teeth when the posterior teeth are in contact. Resin bonded FPDs can be used in this scenario since there is no excessive force on the anterior teeth.
- \(Deep\ bite\): This is an occlusion that results in excessive overlap of the anterior teeth, causing stress on the anterior portion of the FPD. This can lead to complications such as debonding and fracture of the resin bonded prosthesis due to excessive masticatory forces.
- \(Cross\ bite\): This is an abnormal relation of one or more teeth when they do not properly align with their opposing teeth. While resin bonded FPDs might be less optimal, they can still be used if carefully planned.
- \(Bilateral\ cross\ bite\): Similar to unilateral cross bite but involving both sides of the dental arch. This condition still allows for the use of resin bonded FPDs with caution in terms of planning and occlusal adjustment.
- Conclusion:
The deep bite condition puts excessive stress on the marginal areas of the resin bonded FPD, increasing the risk of failure due to debonding or fracture. Therefore, it is not indicated in patients with a deep bite.
Thus, the correct answer is Deep bite.