Search PubMed⌕ Search

Biomedical subjects

Avishai Sadan

Publications and source records attributed to Avishai Sadan.

At least 37 records · Page 2Linked to original sources
PubMed2004

Single-implant restorations: a contemporary approach for achieving a predictable outcome.

The replacement and restoration of missing single teeth with dental implants are routine procedures. However, because of the relatively short clinical history of this procedure in dentistry, custom-tailored protocols for this procedure do not exist. This article will outline the various surgical and restorative steps involved in the treatment planning, fabrication, and delivery of single-implant restoration, and will critically analyze the existing clinical concepts and provide recommendations based on a contemporary approach. As data for and experience with this procedure increase the same general guidelines for all types of implant restorations may not apply. Emphasis will be placed on differentiating between the various types of single-implant restorations, comparing and contrasting the differences between the different types of single-implant restorations, and revising some of the existing concepts of this treatment modality.

Anodontia↗
PubMed2004

Fixed partial denture or single-tooth implant restoration? Statistical considerations for sequencing and treatment.

The choice to replace a single missing tooth can be based on the primary decision that the restorability of the tooth is in doubt. Many teeth are decimated by incipient or recurrent caries, trauma, endodontic complications, or periodontal disease which requires extraction. It is our objective to familiarize the participant with literature comparing success rates of fixed partial dentures and single-tooth implant restorations and a repertoire of prosthodontic techniques used in replacement of single missing teeth with osseointegrated dental implants. The fixed partial denture (FPD) has been regarded as the standard of care for some time in replacement of single and multiple missing teeth. Many studies surveying long term survival have been compiled and analyzed to arrive at a generalized outcome. Most of these studies arrive at common conclusions. Studies surveying success of single-tooth implant-supported restorations are not comparably abundant nor survey for comparable time as those for FPDs. Although, many of the outcomes are statistical survival estimates such as Kaplan-Meier survival tables, implant restorations in partially dentate patients are a predictable means of tooth replacement. There are certain factors which make FPD more appropriate and conversely factors which make an implant restoration more appropriate. Indications and contraindications for each treatment scenario will also be reviewed based on the literature and clinical experience. It is hoped that the practitioner will be able to appropriately identify those cases in which either an FPD or an implant restoration is the appropriate treatment option.

Contraindications↗
PubMed2004

In vitro evaluation of shear bond strengths of resin to densely-sintered high-purity zirconium-oxide ceramic after long-term storage and thermal cycling.

STATEMENT OF PROBLEM: The few available studies on the resin bond to zirconium-oxide ceramic recommend airborne-particle abrasion and modified resin luting agents containing adhesive monomers for superior and long-term durable bond strengths. It is unknown whether this regimen can also be successfully applied to the intaglio surface of a commercial zirconia-based all-ceramic system. PURPOSE: The purpose of this study was to evaluate and compare bond strengths of different bonding/silane coupling agents and resin luting agents to zirconia ceramic before and after artificial aging. MATERIAL AND METHODS: Composite cylinders (2.9 mm x 3.0 mm) were bonded to airborne-particle-abraded intaglio surfaces of Procera AllZirkon specimens (n=80) with either Panavia F (PAN) or Rely X ARC (REL) resin luting agents after pretreatment with Clearfil SE Bond/ Porcelain Bond Activator (Group SE). In another group, Rely X ARC was used with its bonding/silane coupling agent (Single Bond/Ceramic Primer, Group SB). PAN without any bonding/silane agent (Group NO) was the control. Subgroups of 10 specimens were stored in distilled water for either 3 or 180 days before shear bond strength was tested. One hundred eighty-day-old specimens were repeatedly thermal cycled for 12,000 cycles between 5 and 60 degrees C with a 15-second dwell time. Data were analyzed with 1- and 2-way analysis of variance and the Tukey multiple comparisons test (alpha=.05). Failure modes were examined under original magnification x25. RESULTS: After 3 days, SE-REL (25.15 +/- 3.48 MPa) and SE-PAN (20.14 +/- 2.59 MPa) groups had significantly superior mean shear bond strengths (P=.0007) compared with either NO-PAN (17.36 +/- 3.05 MPa) or SB-REL (16.90 +/- 7.22 MPa). SE-PAN, NO-PAN, and SB-REL groups were not significantly different. Artificial aging significantly reduced bond strengths. After 180-day storage, SE-PAN (16.85 +/- 3.72 MPa), and SE-REL (15.45 +/- 3.79 MPa) groups demonstrated significantly higher shear bond strengths than NO-PAN (9.45 +/- 5.06 MPa) or SB-REL (1.08 +/- 1.85 MPa) groups. The modes of failure varied among 3-day groups but were 100% adhesive at the ceramic surfaces after artificial aging. CONCLUSION: Artificial aging significantly reduced bond strength. A bonding/silane coupling agent containing an adhesive phosphate monomer can achieve superior long-term shear bond strength to airborne-particle- abraded Procera AllZirkon restorations with either one of the 2 resin luting agents tested.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2004

Prosthetic design considerations for anterior single-implant restorations.

UNLABELLED: The anterior single-implant restoration provides a predictable solution for the partially edentulous patient. The two main approaches in prosthesis design for the single-implant restoration are the screw-retained and cement-retained restorations. Although both approaches have been proven to work from a standpoint of long-term implant stability, other considerations arise when esthetic outcome and ease of fabrication and delivery are discussed. To guarantee a predictable outcome, the dentist should choose a design that offers maximum prosthetic versatility. Combining prosthetic versatility with ease of delivery is often a clinical and laboratory challenge. Prostheses designs that provide the freedom to select a wide variety of restorative materials may be cumbersome to deliver and maintain and vice versa. This article reviews the advantages and shortcomings of each design and provides an alternative prosthesis design that combines the favorable aspects of these two restorations. CLINICAL SIGNIFICANCE: Screw-retained and cement-retained prostheses are the common designs for single-implant restorations and possess clinical advantages and shortcomings. An alternative and affordable design, that is mainly beneficial when standard stock implants components are used, is presented. It enables the clinician to achieve optimal esthetics in the esthetic zone combined with a simple and time-efficient delivery.

Dental Implantation, Endosseous↗
PubMed2004

In vitro durability of the resin bond to feldspathic ceramics.

PURPOSE: To measure and compare shear bond strength of three different resin-based composite cements (Panavia 21, Noribond DC, and Variolink II) to two feldspathic ceramic materials (Noritake EX-3 and Ceramco) after 3 days (at baseline) and after 180 days of water storage and repeated thermocycling. METHODS: Composite cylinders were bonded with Panavia 21, Noribond DC, and Variolink II to the hydrofluoric acid (HF)-etched surfaces of either Noritake Super Porcelain EX-3 (NEX) or Ceramco (CER) following the manufacturers' directions. Subgroups of 15 specimens were stored in distilled water for either 3 days without thermocycling or 180 days with 12,000 thermal cycles. Shear bond strength was measured and compared by loading each specimen in shear to failure in an Instron testing system. Data were analyzed with a three-factor ANOVA model. Post-hoc multiple comparisons of the individual main-effect levels were performed with Tukey's HSD multiple comparison procedure (alpha = 0.05). RESULTS: Mean bond strength did not differ for the two ceramic materials. Differences in mean bond strength were found among the bonding systems and between the early and late time points. Panavia exhibited significantly lower bond strength as compared to Noribond and Variolink II for both early and late time points, with a greater difference at 180 days. For all groups, failure modes were almost exclusively cohesive in the ceramic, which indicates sufficient resin-ceramic bonds with all tested materials.

Acid Etching, Dental↗
PubMed2004

Replacement of missing maxillary canines with dental implants: prosthesis design considerations.

Replacing a missing canine with a dental implant is the optimal treatment plan. The strategic roles canines play in maintaining normal function and the high visibility of these teeth, especially in the maxilla, require a restoration that provides uncompromised function and aesthetics. Eliminating lateral forces on the implant can minimize implant complications, but in young patients (ie, with steep canine guidance) achieving such a goal presents a restorative challenge. This article discusses several considerations (ie, ease of maintenance, retrievability) that will affect the design of the definitive restoration.

Adult↗
PubMed2003

In vitro evaluation of long-term bonding of Procera AllCeram alumina restorations with a modified resin luting agent.

STATEMENT OF PROBLEM: Bonded densely sintered aluminum oxide ceramic restorations such as Procera AllCeram laminates rely on a strong and long-term durable resin bond. Air particle abrasion and a phosphate-modified resin luting agent have the potential to provide such bonds to aluminum oxide ceramics, but their efficacy on the Procera AllCeram intaglio surface is unknown. The inherent microroughness of this surface may influence bond strengths, because micromechanical interlocking is a main contributor for adhesion of resins to ceramic materials. PURPOSE: This study evaluated the bond strength of a phosphate-modified resin luting agent with and without silanization to an air particle-abraded Procera AllCeram intaglio surface compared with a conventional resin-bonding system before and after artificial aging. MATERIAL AND METHODS: Sixty square (10 x 10 x 2 mm) specimens of Procera AllCeram alumina ceramic with the Procera intaglio surface were air particle abraded with aluminum oxide. Composite cylinders (2.9 mm in diameter and 3.0 mm in width) were fabricated with Z-250 composite and bonded to the ceramic specimens with either Panavia 21 TC or Rely X ARC (control) and their corresponding bonding/silane coupling agents. In addition, Panavia was used without silanization as suggested in similar studies. Subgroups of 10 specimens were stored in distilled water for either 3 or 180 days before shear bond strength was tested with a universal testing machine (MPa) until fracture. The 180-day specimens were subjected to thermocycling at 2000 cycles every 30 days (12,000 cycles total). Data were analyzed with 1-way analysis of variance and Tukey's multiple comparison (alpha=.05). Failure modes were examined with a light microscope (original magnification x 25). RESULTS: Differences between short-term and long-term groups were highly significant (P=.000). Bond strength with Rely X ARC and its silane coupling agent (22.75 +/- 4 MPa) decreased significantly (P=.000) after artificial aging (3.32 +/- 3.62 MPa). Panavia 21 after silanization revealed significantly different (P=.003) early (21.42 +/- 4.3 MPa) and late (16.09 +/- 2.37 MPa) bond strengths but achieved the highest bond strength after artificial aging. Bond strengths of Panavia without silanization both early (8.06 +/- 2.1 MPa) and late (6.91 +/- 2.49 MPa) were not significantly different. Failure modes were mainly adhesive at the ceramic surface for all groups. CONCLUSION: Panavia 21 in combination with its corresponding bonding/silane coupling agent can achieve an acceptable resin bond to the air particle-abraded intaglio surface of Procera AllCeram restorations after artificial aging, which had mixed effects on the other investigated groups. The conventional resin luting agent revealed the most dramatic decrease in bond strength.

Adhesiveness↗
PubMed2003

Long-term resin bond to densely sintered aluminum oxide ceramic.

BACKGROUND: Densely sintered aluminium oxide ceramic is a popular material for ceramic copings and all-ceramic restorations. A strong, predictable, and long-term durable resin bond is key for long-term clinical success of bonded alumina-based restorations. PURPOSE: The purpose of this study was to measure and compare in vitro shear bond strengths of three resin cements with and without their corresponding silane coupling/bonding agent to air particle- abraded densely sintered aluminum oxide ceramic after long-term water storage and thermocycling. MATERIALS AND METHODS: Composite resin cylinders were bonded to air particle-abraded samples of densely sintered aluminum oxide ceramic with Noribond DC (Noritake Dental Supply, Inc., Aichi, Japan), Panavia 21 EX (Kuraray, Osaka, Japan), and Variolink II (Ivoclar Vivadent, Schaan, Liechtenstein), which were used with and without their corresponding silane coupling and bonding agents (n = 15). All specimens (N = 90) were stored for 180 days in water and subjected to repeated thermocycling for a total of 12,000 cycles before shear bond strength was tested. Data were analyzed with the Kruskal-Wallis test and the Wilcoxon two-sample rank sum test at the 5% level of significance. RESULTS: Most groups had no or only minimal bond strength to densely sintered alumina after simulated aging. Panavia had the highest bond strength without silane/bonding agent application. Noribond with its silane/bonding agent revealed the highest overall bond strength, which was significantly greater than that of either Variolink or Panavia after silanization. CONCLUSIONS: Resin cements revealed significantly different bond strengths, and the use of silane coupling and bonding agents had various effects on the resin bond to pure densely sintered alumina. CLINICAL SIGNIFICANCE: Selection of the proper cement/bonding system is fundamental to clinical long-term success of bonded alumina-based restorations. Noribond with its bonding agent and ceramic primer seem to fulfill these requirements under clinically relevant testing conditions.

Air Abrasion, Dental↗
PubMed2003

Influence of silanization on early bond strength to sandblasted densely sintered alumina.

OBJECTIVE: The increased popularity of alumina-based restorations has resulted in an interest in proper adhesive techniques to assure a strong and predictable bond to these restorations. This study investigated the early bond strength of three different resin-cement systems to densely sintered alumina (aluminum-oxide ceramic) with and without the use of their corresponding silane coupling agent (silanization). METHOD AND MATERIALS: Ninety samples of densely sintered high-purity aluminum-oxide ceramic were randomly divided into three groups. Composite cylinders were bonded to the ceramic samples with three resin-cement/bonding-agent systems: Noribond DC (NOR), Panavia 21 EX (PAN), and Variolink II (VAR). Each resin-cement/bonding-agent system was used with and without their corresponding silane (SIL) coupling agent (n = 15). After fabrication, the specimens were stored in distilled water for 3 days at room temperature, and shear bond strength was tested. RESULTS: Application of the silane-coupling agent on sandblasted densely sintered alumina did not significantly influence bond strengths with PAN. Silanization significantly improved shear bond strengths with NOR and VAR. NOR-SIL and VAR-SIL revealed the statistically highest values, with NOR-SIL showing the highest mean bond strength of all groups. CONCLUSIONS: Silanization of sandblasted densely sintered alumina had mixed effects on the applied resin cements: It had no effect on the performance of the phosphate-modified resin cement PAN, but significantly improved shear bond strength of the Bis-GMA composite resin cements VAR and NOR. NOR-SIL revealed the highest overall mean bond strength.

Aluminum Oxide↗
PubMed2003

Post placement and cementation: Part 2.

In situations with thin remaining root walls, the clinician should not attempt to place an extremely wide post that will engage the canal walls. Rather, the practitioner should use a thinner post and a resin cement that will create a custom-fitted, cement-post complex.

Cementation↗