title: Effects of a cementing technique in addition to luting agent on the uniaxial retention force of a single-tooth implant-supported restoration: an in vitro study.
abstract: OBJECTIVE
  Excess residual cement around the implant margin has been shown to be detrimental to the peri-implant tissue. This in vitro study examines the retentive strengths of two different cementing techniques and two different luting agents on a machined titanium abutment and solid screw implants. The amount of reduction of excess cement weight between the two cementation techniques was assessed.
  
  
  METHODS
  Forty gold castings were fabricated for 4.1 mm in diameter and 10 mm in length solid-screw dental implants paired with 5.5-mm machined titanium abutments. Twenty implants received a provisional cement, and 20 implants received a definitive cement. Each group was further divided into two groups. In the control group, cement was applied and the castings seated over the implant-abutment assembly. The excess cement was then removed. In the study group, a "practice abutment" was used to express excess cement prior to cementation. The weight of the implant-casting assembly was measured and the residual weight of cement was calculated. The samples were then stored for 24 hours at 100% humidity prior to tensile strength testing.
  
  
  RESULTS
  Statistical analysis revealed significant differences in tensile strength across the groups. Further Tukey tests showed no significant difference in tensile strength between the practice abutment technique and the conventional technique for both definitive and provisional cements. There was a significant reduction in residual cement weight, irrespective of the type of cement, when the practice abutment was used prior to cementation.
  
  
  CONCLUSIONS
  Cementation of implant restorations on a machined abutment using the practice abutment technique and definitive cement may provide similar uniaxial retention force and significantly reduced residual cement weight compared to the conventional technique of cement removal.
authors.affiliation: Center for Implant Dentistry, College of Dentistry, Health Science Center, University of Florida, Gainesville, FL 32610-0416, USA. prosthodontist@zoho.com
authors.forename: Robert E
authors.initials: RE
authors.lastname: Santosa
authors.forename: William
authors.initials: W
authors.lastname: Martin
authors.forename: Dean
authors.initials: D
authors.lastname: Morton
mesh_terms: D000704:Analysis of Variance; D003442:Crowns; D000044:Dental Abutments; D001840:Dental Bonding / Q000379:methods*; D003738:Dental Cements / Q000737:chemistry*; D019250:Dental Implants, Single-Tooth; D017267:Dental Prosthesis Design; D017268:Dental Prosthesis Retention / Q000379:methods*; D019094:Dental Prosthesis, Implant-Supported / Q000295:instrumentation*; D003793:Dental Restoration, Permanent / Q000379:methods; D005899:Glass Ionomer Cements / Q000737:chemistry; D019279:Resin Cements / Q000737:chemistry; D018709:Statistics, Nonparametric; D013718:Tensile Strength; D015034:Zinc Oxide / Q000737:chemistry
chemical_list: D003738:Dental Cements; D005899:Glass Ionomer Cements; D019279:Resin Cements; D015034:Zinc Oxide