Chandur Wadhwani: Implants, cement and peri-implantitis - science and the missing link

Cementation procedures and materials have been reported to cause complications in implant prosthetics, mainly inflammation around the implant due to cement material excess. Cementation procedures are a complex system, not all the dimensions of which seem to be fully understood and clinically evidence based, still today. Cements have been developed for restoration procedures on natural teeth and are based on preparation techniques and designs which are decades old and do not pay attention to designs being considerably different in implant based restoration. Dr Wadhwani points out, that modern implant protocols with reduced diameter implants and at times subcrestal implant placement create horizontal overhangs and leave soft tissue attachments and pockets depths up to 5 and more mm. Studies show that it is not possible to remove cement remnants in this depth, and that cement excess is one of the main risk factors for peri-implant disease complications. Due to the weaker fiber bundle constitution around implants and hemidesmosomal attachment, in comparison to the natural tooth, the high pressure forces during cementation procedures can destroy the fiber network and even diffuse cement material into the spongeous bone. Some cement formulations featuring very low film thickness, cement material can even be pressed into the the tissue and cause giant cell foreign body reactions. Based on the formulation, cements can show some antimicrobial effect on peri-implant inflammation relevant bacteria (such as Aggregotibacter act., Porphyromonas g., Fusobacterium nucl.), or not, and can have allergic effects. Dr Wadhwani concludes that with assistance of computational fluid dynamics we should develop a better understanding of the abutment-crown-cement system and that to avoid cement related complications, whenever possible, screw-retained systems should be the method of choice.