Clinical versus laboratory adhesive performance to wet and dry demineralized primary dentin

Purpose: To evaluate the influence of dentin moisture on bond strengths of an etch-and-rinse bonding agent to primary dentin clinically and in the laboratory. Methods: The sample consisted of two groups of 20 caries-free primary second molars: molars in exfoliation period (clinical group) and extracted molars (laboratory group). Class I cavities were prepared in all specimens leaving a flat dentin surface on the pulpal floor. A two-step etch-and-rinse adhesive was vigorously rubbed on either dry (n= 5) or wet demineralized dentin (n= 5) under clinical or laboratory conditions. After restorative procedures, the teeth from the clinical group were extracted after 20 minutes. All samples were processed and underwent microtensile bond strength test and silver nitrate uptake evaluation under scanning electron microscopy. Results: Statistically higher bond strength values were observed when the bonding was performed under laboratory conditions and on a wet demineralized dentin. Most of the failures were adhesive and mixed irrespective of the experimental condition. Silver nitrate uptake occurred in all groups irrespective of the experimental condition. Resin-dentin bond strengths produced in the laboratory in primary teeth may overestimate those produced under clinical circumstances. (Am J Dent 2011;24:221-225).

Conclusions

The researchers focussed on the impact of the heroin shortage that occurred in early 2001 on three Australian jurisdictions, namely NSW, Vic and SA. They interviewed 82 heroin dependent heroin users and 172 key informants from health and law enforcement agencies. They also examined a range of indicator data such as drug seizures, drug-related arrests, deaths related to drug use, emergency department admissions for overdose or drug induced psychosis , calls to telephone help lines about drug use, needles distributed for drug use, and notifications about blood borne diseases. In addition a range of documentation, in particular from the law enforcement sector, was examined.