Written by George Freedman, DDS Tuesday, 15 October 2013 08:08
In First Impressions George Freedman, DDS, gives readers a brief summary of products that have recently been introduced to dentistry, based on his clinical experience.
Panavia SA Cement
The clinical standards for today’s resin cement include self-adhesion and single-step delivery. Yesterday’s products were multicomponent, multistep, tedious, and confusing. As cements must adhere to a majority of the indirect dental restorative materials in common use today, they must also have high bond strengths to resist marginal leakage and failure. Kuraray Dental’s well-known Panavia cement line has long been a mainstay of many practices. The recently introduced single-step, self-adhesive Panavia SA Cement was developed for cementing indirect restorations made of metal, all-ceramic (zirconia), hybrid ceramics, and composites. It offers excellent adhesion to enamel, dentin, metal, and zirconia, and the bond strength is independent of the dryness or wetness of the substrates. Its low water sorption provides predictable and long-lasting marginal integrity. The material’s low film thickness offers optimal cementation, particularly with closely adapted milled restorations. Panavia SA Cement is also a fluoride-releasing, dual-cure resin cement. It is easy to remove excess cement without gingival trauma, making it ideal for implant cementation. From a clinical perspective, Panavia SA Cement is very easy to use because there are no primers, silane, or bonding agents required. The self-adhesive chemistry makes the one-step approach practical and efficient. There is virtually no postoperative sensitivity. The cement is offered in 2 delivery formats: the convenient automix allows the cement to be applied through the mixing tip directly into the crown or the canal (post cementation), and the economical hand mix eliminates the cost of the mixing tip, requiring a pad mix prior to placement into the crown. In either of these formats, a single sy-ringe can yield 50 to 60 crown cementations for crowns, bridges, porcelain, ceramic, hybrid ceramics, composite resin, and metal as well as metal and glass-fiber posts.
MiraTray Implant Impression Tray
The implant impression appointment should be a relatively uncomplicated one. The healing caps are removed, the impression posts are inserted and verified radiographically, the impression is taken, and the impression posts are sent to the lab while the patient goes home with the replaced healing caps. Choosing the impression tray is a different matter altogether; a closed or open tray? If an open tray is selected, is it necessary to fabricate a custom tray—laboratory costs and an additional appointment are required—or can the practitioner modify a disposable plastic tray? Hager Worldwide has developed the innovative MiraTray Implant Impression Tray to solve this annoying problem. The tray consists of a rigid plastic frame that ensures the integrity of the impression. The occlusal base of the tray is made of a transparent foil material that contains the impression material, allowing the impression posts to push through with gentle manual pressure. The tray can be tried over the arch with the impression post(s) in place to verify size and positioning. The appropriate impression materials are placed into the tray. The filled MiraTray is inserted over the arch and the impression post(s) with gentle finger pressure until the impression post(s) perforate the plastic foil. Once the impression is polymerized, the impression posts are loosened, releasing the tray with the posts firmly embedded. The healing caps are replaced until the next appointment. The MiraTray technique (3 sizes available each for maxilla and mandible) saves an appointment and lab costs, and it eliminates the stress of grinding a disposable tray. The Mira-Tray precision “pickup” technique is comfortable for the patient and fast and easy for the practitioner.