David C. Appleby

The combined reversible hydrocolloid/irreversible hydrocolloid impression system

1. Dentloid, a reversible hydrocolloid which had been altered to bond to irreversible hydrocolloid, demonstrated a bond with three irreversible hydrocolloids tested in combination with it. 2. Two conventional reversible hydrocolloids exhibited such weak bonding with irreversible hydrocolloid that it was impossible to make impressions with them. 3. The three irreversible hydrocolloids exhibited different bond strengths with Dentloid. 4. The Dentloid/irreversible hydrocolloid combination with the lowest bond strength exhibited the lowest dimensional stability. 5. Combined impressions of Dentloid with two of the three irreversible hydrocolloids exhibited dimensional stability that is a clinically acceptable. 6. Combinations of Dentloid with irreversible hydrocolloids not covered in this report should be verified for acceptable dimensional stability before clinical use. 7. The combination technique, in itself, proved to be easy and practical and overcomes many of the shortcomings inherent to conventional reversible hydrocolloid impression techniques. 8. Strict adherence to laboratory procedures for pouring a cast is as critical as for the conventional technique.