Evaluation of UCLA Implant-Abutment Sealing

Marcelo B. Ramos, Luiz F. Pegoraro, Esther Takamori, Paulo G. Coelho, Thelma L. Silva, Estevam A. Bonfante

Research output: Contribution to journalArticlepeer-review


Purpose: To evaluate the effect of the presence of a prefabricated cobalt-chromium (CoCr) margin in a universal castable long abutment (UCLA) on the sealing capability and fit of the implant-abutment interface. Materials and Methods: One-hundred twenty external hexagon implants (SIN) were divided into two groups (n = 60 each) to receive UCLA abutments from six manufacturers (n = 10 each) either with or without a CoCr margin (n = 60 each). Abutments were cast and 12 groups were formed: M (Microplant), I (Impladen), S (SIN), Sv (Signo Vinces), T (TitaniumFix), and B (Bionnovation). Sealing was determined by placing 0.7 µL of 0.1% toluidine blue in the implant wells before abutment torquing. Implant-abutment samples were placed into 2.0-mL vials containing 0.7 mL of distilled water to maintain the implant-abutment interface, and aliquots of 100 µL of water were retrieved at 1,3, 6,24, 48, 72,96, and 144 hour incubation times for measurement of absorbance in a spectrophotometer, and returned for repeated measurements. Two-way ANOVA (P < .05) and Tukey’s test were used. Scanning electron microscopy (SEM) was used for observation of the implant-abutment fit. Results: Groups M, Sv, and T without the CoCr margin resulted in complete release of toluidine blue at 1 hour, whereas I, S, and B did so at 3, 24, and 96 hours, respectively. Complete leakage in abutments with the prefabricated margin occurred at 6 hours for S; 24 hours for Sv, T, and B; and 72 hours for M and I. Implant-abutment gaps were observed in all groups. A poorer fit was depicted for groups M and T without the CoCr margin. Conclusion: Complete leakage was observed for all UCLA abutments regardless of the presence of the CoCr margin. Implant-abutment gaps were observed in all groups. Int J Oral Maxillofac Implants 2014;29:113–120. doi: 10.11607/jomi.3217

Original languageEnglish (US)
Pages (from-to)113-120
Number of pages8
JournalInternational Journal of Oral and Maxillofacial Implants
Issue number1
StatePublished - Feb 14 2014


  • dental implant
  • gap
  • implant-abutment connection
  • in vitro
  • microleakage, spectrophotometry

ASJC Scopus subject areas

  • Oral Surgery


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