|Brief resume of the intended work:
Need for the study:
Cement-retained, implant-supported prostheses have gained popularity because they allow completion of clinical procedures using conventional fixed prosthodontic techniques. In the absence of occlusal screw access openings, these prostheses offer improved esthetics and occlusal contacts. Cemented prostheses compensate for minor fit discrepancies through the use of luting agent. One of the major concerns with cemented prostheses is the challenge of retrieval when an abutment screw loosens1.
This conundrum focuses attention on the choice of cement. On one hand, selection of cement that is too retentive could make retrieval of prosthesis difficult; on the other hand, the selection of cement that is not retentive enough could be a source of embarrassment for the patient2.
There is limited literature evaluating the retentive capabilities of luting agents when used with an implant system3. Off late there is introduction of some cements specifically formulated for this purpose and manufacturers claim several advantages. However, very few studies have been conducted on purposely-designed implant cements.
The purpose of this study is to assess the retentive nature of purposely-designed implant cement and to compare its retentiveness with common dental cements that are used with implant systems.
Review of literature:
A study was conducted to compare the effect of 20 degrees and 30 degrees of total occlusal convergence, the occlusocervical dimension, and the type of cement on the tensile resistance to dislodgement of cement retained implant restorations. It was found that preparations with 20 degrees of total occlusal convergence and 8mm of occlusocervical dimension had higher retentive values. And highest tensile strength was seen with acrylic /urethane cement, followed by zinc phosphate cement and lowest with zinc oxide eugenol cement1.
An invitro study was conducted for cement selection for Cement- retained crown technique with dental implants. It was found that polycarboxylate cement had highest retentive strength while Premier implant cement and zinc oxide eugenol have statistically similar retentiveness. Author suggested that not any one of the cements is better than another in retaining cement-retained crowns to implant abutments2.
A study was conducted to evaluate the retentiveness of dental cements used with metallic implant components. It was found that resin cement had highest retentive strength followed by zinc phosphate and resin-reinforced GIC, while GIC and zinc oxide-non-eugenol cement exhibited lowest retentive strength3.
In an invitro study designed to evaluate tensile bond strengths of provisional luting agents used with an implant system, it was inferred that Temp Bond and Provilink luting agents exhibited the lowest tensile bond strength as compared to Neo-Temp luting agent4.
A study was attempted to determine the effect of abutment dimension and type of luting agent on the retention of the prosthetic crown and it was concluded that definitive luting agent produced greater uniaxial retention forces than provisional cement5.
Objectives of the study
To evaluate the retentiveness of purposely-designed implant cement (Premier Implant cement) used to cement metal restorations onto machined implant abutments.
To evaluate the retentiveness of common dental cements used to cement metal restorations onto machined implant abutments.
To compare the retentiveness of purposely-designed implant cement (Premier Implant cement) with common dental cements.
Materials and Methods:
Source of data:
Commercially available Implant analog and abutment will be used. Purposely-designed implant cement (Premier Implant cement), Zinc polycarboxylate cement, Zinc oxide eugenol cement, Glass ionomer cement and Zinc phosphate will be used.
Method of data collection:
The study will comprise of 50 specimens divided into 5 groups. Each group will contain 10 specimens.
GROUP 1- Purposely-designed implant cement (Premier Implant cement) used as luting agent between crown and implant abutment.
GROUP 2- Zinc polycarboxylate cement used as luting agent between crown and implant abutment.
GROUP 3- Zinc oxide eugenol used as luting agent between crown and implant abutment.
GROUP 4- Glass ionomer cement used as luting agent between crown and implant abutment.
GROUP 5- Zinc phosphate cement used as luting agent between crown and implant abutment.
Retentiveness of luting agents used between cast metal restorations cemented onto machined metal implant abutments will be measured with a universal testing machine.
Data will be analyzed using analysis of variance (ANOVA) test.
Does the study require any investigation or intervention to be conducted on the patients or humans or animals? If so please describe briefly:
Has ethical clearance been obtained from your Institution in case of 7.3
LIST OF REFERENCES:
1.Bernal G, Okamura M, Munoz CA. The effects of abutment taper, length and cement type on resistance to dislodgement of cement-retained, implant-supported restorations. J Prosthodont 2003;12:111-5.
2. Sheets JL, Wilcox C, Wilwerding T. Cement selection for cement-retained crown technique with dental implants. J Prosthodont 2008;7:92-6.
3. Squier RS, Agar JR, Duncan JP, Taylor TD. Retentiveness of dental cements used with metallic implant components.Int J Oral Maxillofac Implants 2001;16:793-8.
4. Ramp MH, Dixon DL, Ramp LC, Breeding LC, Barber LL. Tensile bond strengths of provisional luting agents used with an implant system. J Prosthet Dent 1999;81:510-4.
5.Covey DA, Kent DK, St. Germain HA, Koka S. Effects of abutment size and luting cement type on the uniaxial retention force of implant-supported crowns. J Prosthet Dent 2000;83:344-8.