Purpose: The purpose of this study was to investigate with 3
dimensional measurement system whether the stabil condition of
mandibular alveolar ridge may recorded by the impression materials.
Materials and Methods: The study was performed on the 14
edentulous patients. Patients were divided in two groups. Zinc-oxide
eugenol (ZOE) impression material was used as a final impression
material in group I and Polyvinylsiloxane (PVS) impression material
was used in group II and the definitive cast was obtained. A final
impression was made again from all patient with a impression plaster
(IP) by means of the custom tray has a new design for each patient.
This custom tray was prepared on the definitive cast. The peripheral
border line was drawn roughly and the 14 references point were done
on the alveolar ridge on the definitive casts. The photographs of the
definitive casts were took by Nikon E2/E2s and the three dimensional
images were carried out. Height of alveolar ridge, quantity of denture
bearing area and length of peripheral border line was measured on
the three dimensional images.
Results: This study showed that all measurement values of the IP were
higher than the others. The measurement values of the ZOE were
lower than the IP, but not statistically significant (p>0.05). However,
the measurement values of PVS showed that the decrease of height of
the alveolar ridge was statistically significant (p< 0.05).
Conclusion: The effect of impression materials on the alveolar
mucous membrane is vary depending on their properties and the
custom tray design. For that reason, it is too important that the choice
of impression material and impression technique when the mandibuler
complete denture impression is made from edentulous patient has
unsupported residual alveolar ridge. It is suggest that an mandibular
complete denture impression is made with IP and ZOE.
Key Words: Complete denture impression technique, 3-Dimensional
measurement system