Procera® Titanium
Oxide Crown

New
Bond Strength of Porcelain to Grade 2 Titanium

Abstract: The precision of fit and biocompatibility of titanium crowns and bridges have been studied and found to be excellent for multiple dental applications However, historically the strength of the bone between dental porcelains designed for addition to titanium substructures has been a major question. Therefore, a study was initiated comparing the adhesiveness or bone strength of 4 commercially available dental porcelains to grade 2 titanium. Twenty-four rectangular bars of Grade 2 Titanium (25 mm long X 3 mm wide X 0.5 mm thick) were obtained for addition of porcelain. Each group of samples contained 6 specimens of each porcelain/titanium combination. Four commercially available titanium porcelains were prepared onto the substrate according to the manufacturer’s recommendations. Opaque and dentin porcelain layers were applied symmetrically over a length of 8 mm to a total thickness of 1.1 mm (after firing). Bone strength tests were performed according to ISO 9693, test 6.3.3 – metal-ceramic bond characterization. The Scwickerath crack initiation test provided the following results with a measurement certainty of 3.0 MPa. Duceratin 28.7 MPa, Duceratin Plus 29.0 MPa, Noritake Ti-22 35.0 MPa and Triceram 26.7 MPa.
Conclusions: Bond strength tests according to ISO 9693, test 6.3.3 revealed that all of the Titanium porcelains included in this study passed the ISO requirements.

Abstract: With the increasing use of titanium in fixed and removable dental prostheses, the methods for maintenance have come under discussion, particularly the polishing sequence for titanium. Therefore, the purpose of this project was to determine an appropriate sequence and instrumentation for polishing the titanium of the Procera AllTitan crown. Thirty test samples of commercially pure grade two (2) titanium were obtained from Nobel Biocare, AB for this study. The surface of each sample was sandblasted with 110 µm aluminous oxide at 60 psi to establish a baseline surface roughness. Two samples were devoted to each of 15 different polishing sequences which included combinations of polishing compounds and instruments: sandpaper discs, emery discs, various rubber polishing wheels and discs, pumice, buffing bar compound, white diamond, diamond paste, tin oxide, rouge, bristle brushes, polishing cups, and felt and rag wheels. Scanning electron photomicrographs of the polished samples were made at 100X magnification and randomly assigned I.D. numbers. The photomicrographs were evaluated and ranked by six dentists from best to worst regarding surface smoothness.
Conclusions: It was concluded that the best surface was the surface polished with the following sequence: aluminous oxide stone, green rubber wheel, white rubber wheel, flour of pumice on a wet rag wheel, buffing bar compound on a felt wheel, rouge on a felt wheel, and rouge on chamois wheel.

Abstract: In this study, the effect of long-term storage of titanium in water for 22 months on titanium bonded with different adhesives was compared to 24 hour samples. Truncated cones of pure titanium were fabricated with a 5.0 mm sandblasted circular face for bonding to a large titanium sandblasted disc embedded in a plastic ring. A special jig was used to pull the bonded cone from the disc using a Universal Instron tensile testing machine. Ten cones for each adhesive material were bonded to a titanium disc base using: 1) Metabond, 2) Panavia, 3) Allbond-2/C&B resin, and 4) Panavia 21. These 40 samples, after 24 hours of storage in water, were debonded with tensile force. After recording the data, the samples were cleaned and rebonded with the four bonding agents and stored for 22 months in water at 70 degrees. At 22 months, the samples were debonded with tensile force and data recorded. The data were subjected to a Two-way ANOVA followed by a contrast test. The recorded data for the 24 hour samples are followed by the 22 month samples underscored. The values in MPa were: Metabond = 28 ± 1, 19.4 ± 9, Panavia = 57.9 ± 3.1, 58.8 ± 4.7, Allbond-2/C&B resin = 49.5 ± 4.3, 9.7 ± 3, and Panavia 21 = 54.2 ± 8 (24 hours only).
Conclusions: At 22 months, the Panavia values ( 57.9 ± 3.1, 58.8 ± 4.7) were similar to the 24 hour values, while Allbond-2 and Metabond were significantly decreased.

Abstract: The purpose of this study was to evaluate the performance of Procera® AllTitan crowns and bridges in a multicenter clinical trial. This system involves electric discharge machining and copy milling. The metal used is unalloyed titanium, which can be processed as a single coping or multiple units joined to a pontic by laser welding. The single unit coping or the fixed partial denture substructure is then veneered with a low fusing porcelain. The clinical application of this technology was evaluated by six major universities in the United States. One hundred fourteen patients participated in this study, which involved 126 restorations (55 prostheses were placed in the maxillae and 71 were placed in the mandible). There were 179 abutment teeth, 73 were crowns and 53 were three-unit FPDs. Surface and color, anatomic form, and margin integrity were assessed at one-month following cementation and one-year using the California Dental Association (CDA) quality assessment evaluation system. No statistically significant difference in CDA scores between the one-month evaluations and the one-year assessments were found for surface and color (p=0.68), anatomic form (p>0.99), or margin integrity (p=0.57). Using the lowest ranking in the three categories as the overall quality of the restoration, only 3.3% or 2 crowns and 2 FPDs were not acceptable at the one-month visit, and 4.5% or 2 crowns and 3 FPDs at the one-year evaluation. At the one-month visit, 96.6% or 114 of the restorations were judged as satisfactory while 95.5% or 107 restorations were evaluated similarly at the one-year evaluation.
Conclusions: The Procera AllTitan restorations were rated satisfactory using the CDA criteria over 95% of the time following insertion, and maintained this high rating at least for one-year.

Abstract: The purpose of this project is to determine the in vivo wear resistance of the Procera Titanium-Ceramic restoration. The patient population from the University of Michigan School of Dentistry involved in the Nobel Biocare T-027 multicenter longitudinal clinical trial of Procera AllTitan restorations formed the test population for this investigation. Impressions were made and epoxy resin casts poured of the arches and teeth containing the Procera AllTitan restorations following cementation. Similarly, casts were made of the opposing dentitions. After one-year in service, the patients were recalled for a maintenance examination and impressions were again made of the arches containing the restorations and opposing dentitions, and epoxy resin cast fabricated. Using the Laser Videography measurement method, the occlusal surfaces of the Procera AllTitan individual units at baseline and after one year are being compared for wear volume loss. Similar measurements have been made of the opposing dentition at the point of occlusal contact with the Procera crown. At the present time, the restorations and the opposing dentitions for the Procera crown opposing either enamel or a gold alloy have been measured. The data is currently being analyzed.

Abstract: This study investigated the color stability of two different dental porcelains, Ceramco and Procera AllTitan veneering porcelain, after they were exposed to 900 hours of accelerated aging. Twenty titanium plates provided the substrate to which the Procera AllTitan veneering porcelain was fired. Five samples in shades A3, A3.5, C3, and D3 were fired to form four sample groups. Twenty metal-ceramic alloy (Olympia) plates were cast to the same dimensions to form the substrates to which Ceramco porcelain was fired. The four shades of porcelain were again added to each of the samples. Commission International de l'Eclairage L*a*b* readings were recorded with a Minolta Chroma Meter II before and after exposure to 900 hours of accelerated aging in the Weather-O-Meter. After the aging process, the color differences between the pretest and posttest conditions were calculated. Statistical comparisons demonstrated a difference in color change (P< 0.05) between Ceramco and the Procera AllTitan veneering porcelain in three of the shades tested. However both samples demonstrated only a “slight” color change.
Conclusions: In terms of color stability, neither porcelain had “noticeable” change after 900 hours of accelerated aging.