Inhibition of cell survival, viability and proliferation by dentin adhesives after direct and indirect exposure in vitro

Objectives

The influence of dentin adhesive systems (Scotchbond Multi-Purpose, XP Bond, Xeno V, Clearfil Protect Bond, AdheSE) on cell survival, viability and proliferation was characterized after direct and indirect exposure using different cell culture techniques.

Materials and methods

The primers and cured bonding parts were directly exposed to cells using cell culture inserts, and complete materials were analyzed in a dentin barrier test. Cell responses were examined in 3T3 mouse fibroblasts after 24- and 72-h exposure periods by the estimation of total cell numbers (survival), apoptosis (viability) and cell proliferation.

Results

Cell numbers were effectively reduced by the primers of AdheSE, Protect Bond, and Scotchbond Multi-Purpose as well as XP bond after direct exposure in a cell culture insert test device. Likewise, Scotchbond Multi-Purpose primer induced a rate of apoptosis (93.9%) even higher than detected with Protect Bond primer (91.6%). Cell proliferation was entirely inhibited by primers and by Xp Bond as well. The Scotchbond Multi-Purpose was most cytotoxic in a dentin barrier test device after a 24-h indirect exposure. It also increased the percentage of cells in apoptosis to 15.4% compared to untreated controls.

Conclusion

Unpolymerized primers of dentin adhesives were more cytotoxic than polymerized bonding counterparts. Moreover, total etch dentin adhesives were more cytotoxic than self-etch adhesives.

Clinical relevance

When dentin adhesives are used in deep cavities without a protective dentin barrier the leachable hydrophobic and hydrophilic component of dentin adhesive systems can penetrate to the pulp and may induce cytotoxic responses in pulp tissues.     

Segmental vitiligo in a patient with thoracic outlet syndrome

Reported here is a 35-year-old man with findings of thoracic outlet syndrome and bilateral segmental vitiligo on C8–T1 dermatomes. The possible causal relationship between the two disorders under the common denominator of cervical sympathetic involvement is discussed for the first time in the literature.     

Utility of the Rey-15 Recognition Trial to Detect Invalid Performance in a Forensic Neuropsychological Sample

The current study sought to address the utility of the Rey Fifteen Item Test (Rey-15), with the use of a combined score [recall correct + (recognition correct – false positives)], to distinguish between valid and invalid performance among a sample of litigating persons referred for neuropsychological evaluation. Scores on the Rey-15 were analyzed across four comparison groups: (1) litigating persons with evidence of invalid performance (n = 29), (2) litigating persons with valid performance (n = 63), (3) learning-disabled patients (n = 36), and (4) a mixed clinical neuropsychological sample not involved in litigation (n = 54). A Rey-15 combined cutoff score of < 21 yielded the highest sensitivity (70%) and specificity (92.8%) rates. If the Rey-15 is to be used in clinical practice to detect invalid performance, the recognition trial with combined score < 21 should be used. Findings support the use of the combined Rey-15 score in place of the previously used recall Rey-15 score to improve sensitivity and specificity rates for detection of invalid performance in litigating neuropsychological referrals.     

Exeter Short Stems Compared With Standard Length Exeter Stems : Experience From the Australian Orthopaedic Association National Joint Replacement Registry

The standard Exeter stem has a length of 150 mm with offsets 37.5 to 56 mm. Shorter stems of lengths 95, 115 and 125 mm with offsets 35.5 mm or less are available for patients with smaller femurs. Concern has been raised regarding the behavior of the smaller implants. This paper analyzed data from the Australian Orthopaedic Association National Joint Replacement Registry comparing survivorship of stems of offset 35.5 mm or less with the standard stems of 37.5 mm offset or greater. At 7 years, there was no significant difference in the cumulative percent revision rate in the short stems (3.4%, 95% CI 2.4-4.8%) compared with the standard length stems (3.5%, 95% CI 3.3-3.8%) despite its use in a greater proportion of potentially more difficult developmental dysplasia of the hip cases.