Objectives: The aim of this study was to evaluate the influence of artificial ageing on the retention
force of original semipermanent cements, as well as the possibility of using conventional cements
for semipermanent cementation with adequate modification of the cementing protocol. Material and
methods: Forty CoCrMo alloy crowns were divided in four groups (each group n=10) and fixed with
two semipermanent cements (resin-based and glass ionomer-based cements) and one conventional
(zinc phosphate), using conventional and modified cementation techniques on titanium abutments.
The samples were stored in humid conditions for 24 hours at 37°C and subjected to thermocycling
(500 cycles) and mechanical cyclic loading (7 days, 3, 6, 9 and 12 months function simulation). The
cast crowns were removed and the retention force was recorded. Results: The highest initial retention force measured was for zinc-phosphate cement – conventional cementing (198,00±61,90 N), followed in descending order by zinc-phosphate cement – modified cementing technique (152,00±45,42
N), long term temporary cement – GC Fuji Temp LT (57,70±20,40 N), and semipermanent cement – Telio CS Cem Implant (56,10±18,68 N). After 12 months, the highest retention force measured was for
zinc-phosphate cement – conventional cementing (88, 90±14, 45 N), followed by zinc-phosphate cement – modified cementing (48, 15±14,41N), semipermanent cement GC Fuji Temp LT (16,55±3,88 N)
and Telio CS Cem Implant (15,55±5,52 N). Conclusions: Zinc-phosphate cement – modified cementing
technique and original semipermanent cements can be recommended for conditional permanent cementing of implant supported crowns. Clinical relevance: The use of semipermanenet cements and
zinc-phosphate cement – modified cementing technique provides a predictable retrievability of implant-supported crowns.
