hygiene the international C.E. magazine of dental hygiene

I 21hygiene 1_2013 C.E. article_ implant maintenance I _Achieving a balance between implant-sup- ported restoration esthetics and maintaining peri- odontal health is important in an overall successful outcome of the prosthesis. The goal is to create an emergence profile design that allows for minimal tissue displacement while achieving optimal cer- vical contours for esthetics. It is important in the design to allow access for proper cleaning by the patient and clinician (Fig. 1). There are two types of implant restoration de- signs commonly used in single-tooth replacement prosthetics. They are a screw-retained crown or a two-piece abutment and cement-retained crown. The screw-retained crown design is the technique more commonly used in Europe. Whereas, the ce- ment retained crown prosthesis is more frequently used in the United States. The screw-retained restorations contain a small chimney access hole where the screw retaining the restoration is inserted. The crown is screwed directly into the implant and the access chimney is typically closed with a tooth-colored resin (Sarmont, 2009). Therearetwomainadvantagesofthisrestorationde- sign.First,sincecementisnotusedinthismethod,the opportunity for subgingival residual excess cement to remain on the prosthesis cannot occur. When excess cement is left, it can create the opportunity for inflammation and peri-implantitis to develop in the implant sulcus site. Second, the screw can be easily removed from the restoration, allowing for crown removal if necessary during any maintenance procedures. The two-piece abutment and cement-retained crown restoration has an abutment that is designed to provide the subgingival emergence profile and allowsthecrowntobecementedontotheabutment (Fig. 2). The emergence profile refers to the subgin- givalcontoursthatliebetweentheimplantplatform and the emerging abutment and crown (Sarmont, 2009). Using a custom designed abutment provides greater flexibility in determining the proper shape of theemergenceprofilecomparedwithpre-fabricated standard abutment design. To obtain a pleasing restoration, the subgingival contoursmuststartatthesmallcircleoftheimplant head and emerge from the tissue with an anatomi- cal profile (Sarmont, 2009). The result should be an emergence profile that allows for minimal displace- ment of the surrounding tissue while creating an esthetically pleasing appearance (Fig. 3). This design allows for easy access into the implant sulcus area so cleaning and maintaining can be easily achieved by both the patient and the clinician. Over or under contouring of the abutment and/or restoration can result in biofilm retention and peri-implantitis. It is importantfortheemergenceprofiletoresemblethat How implant prosthesis design influences implant maintenance access Authors_Shirley Branam, RDH, MBA, and Gerhard Mora, CDT, BS This article qualifies for C.E. credit.TotaketheC.E.quiz,log on to www.dtstudyclub.com. Subscribers to the magazine may take this quiz for free and willbeemailedanaccesscode after the magazine’s release. If you do not receive the code, contact support@dtstudyclub. com. Non-subscribers may take the quiz for $20. You can accessthequizbyusingtheQR code below. _c.e. credit part IV Fig. 1_Emergence profile and crown should resemble that of a natural tooth so the patient and the clinician can easily maintain the implant prosthesis. (Photos/Provided by G P Mora, CDT) Fig. 2_Custom abutment and crown design. Fig. 1 Fig. 2