The immediate bonding effectiveness of contemporary adhesives is quite favorable, regardless of the approach used. In the long term, the bonding effectiveness of some adhesives drops dramatically, whereas the bond strengths of other adhesives are more stable. This review examines the fundamental processes that cause the adhesion of biomaterials to enamel and dentin to degrade with time. Non-carious class V clinical trials remain the ultimate test method for the assessment of bonding effectiveness, but in addition to being high-cost, they are time- and labor-consuming, and they provide little information on the true cause of clinical failure. Therefore, several laboratory protocols were developed to predict bond durability. This paper critically appraises methodologies that focus on chemical degradation patterns of hydrolysis and elution of interface components, as well as mechanically oriented test set-ups, such as fatigue and fracture toughness measurements. A correlation of in vitro and in vivo data revealed that, currently, the most validated method to assess adhesion durability involves aging of micro-specimens of biomaterials bonded to either enamel or dentin. After about 3 months, all classes of adhesives exhibited mechanical and morphological evidence of degradation that resembles in vivo aging effects. A comparison of contemporary adhesives revealed that the three-step etch-and-rinse adhesives remain the 'gold standard' in terms of durability. Any kind of simplification in the clinical application procedure results in loss of bonding effectiveness. Only the two-step self-etch adhesives approach the gold standard and do have some additional clinical benefits.

http://www.endoexperience.com/documents/DeMunketalDurabiltyofadhesionJDR.pdf

A Critical Review of the Durability of Adhesion to Tooth Tissue: Methods and Results

Hygroscopic and hydrolytic effects in dental polymer networks.

Strength, fracture toughness and microstructure of a selection of all-ceramic materials. Part I. Pressable and alumina glass-infiltrated ceramics.

Background
The brine shrimp lethality assay is considered a useful tool for preliminary assessment of toxicity. It has also been suggested for screening pharmacological activities in plant extracts. However, we think that it is necessary to evaluate the suitability of the brine shrimp methods before they are used as a general bio-assay to test natural marine products for pharmacological activity.

/pdf/a-comparison-between-two-brine-shrimp-assays-to-detect-in-1pdjrndsbg.pdf

A comparison between two brine shrimp assays to detect in vitro cytotoxicity in marine natural products.

Medicinal plants constitute an important component of flora and are widely distrib- uted in India. The pharmacological evaluation of substances from plants is an established method for the identification of lead compounds which can leads to the development of novel and safe medicinal agents. Based on the ethnopharmacological literature, several species of medicinal plants used in traditional medicine in India were collected. In the present study, aqueous extracts of these medicinal plants were screened for their cytotoxicity using brine shrimp lethality test. Out of the 120 plants tested, Pistacia lentiscus exhibited potent brine shrimp lethality with LC50 2.5μg . Aristolochia indica (Aristolochiaceae), Boswellia serrata (Burseraceae), Ginkgo biloba (Ginkgoaceae), Garcinia cambogia (Clusiaceae), and Semecarpus anacardium (Anacardiaceae) have also showed significant cytotoxicity with LC50 13, 18, 21, 22, and 29.5μg respectively. The present study supports that brine shrimp bioassay is simple reliable and convenient method for assessment of bioactivity of medicinal plants and lends support for their use in traditional medi- cine.

/pdf/assessment-of-bioactivity-of-indian-medicinal-plants-using-ipi32wkwlm.pdf

Assessment of Bioactivity of Indian Medicinal Plants Using Brine Shrimp (Artemia salina) Lethality Assay

A new screening test for toxicity testing of dental materials.

IPS Empress inlays and onlays after four years--a clinical study.

The toxic effects of mercury derived from amalgam fillings have been a focus of controversy in Germany during the last 25 years As alternatives to amalgam, composites are used widely to restore anterior and posterior permanent teeth This study quantifies the amount of TEGDMA and methacrylic acid that can be derived from a polymerized commercial hybrid composite material Different specimens were made with different curing methods with and without an oxygen inhibition layer To simulate the removal of composite fillings, some samples were pulverized The specimens were eluted in distilled water at 37 degrees C for different time intervals To check the influence of acid conditions, pulverized material was incubated in 6 M HCl The separation of the eluted chemical resin components was done by HPLC A defined mixture of pure components was used as an external standard for the identification and quantification of the eluted components The results focus on the release of triethylengly-coldimethacrylate (TEGDMA) and methacrylic acid Concerning the different incubation methods, the results showed higher TEGDMA elution with oxygen inhibited surface layer and with the pulverized samples Within acid conditions, the amount of TEGDMA found was low, but the amount of methacrylic acid increased Small resin monomers like TEGDMA are primarily eluted from composite in aqueous solutions Within acid conditions a hydrolytic disintegration of the ester bonding of the monomers could be observed Methacrylic acid--a substance with allergenic potential--could be detected

Elution parameters and HPLC-detection of single components from resin composite.

Sodium hypochlorite is often used as an irrigation solution during routine endodontic treatment. Before recementation of a post-retained crown on the upper left lateral incisor, the root canal was irrigated with sodium hypochlorite. There was no root filling in the root canal, and the apex was open after an earlier apicoectomy. Sudden pain with swelling of the left face side occurred during root canal rinsing. Three years later, a paraesthesia still remained in the affected region and a paralysis of some mimic muscles in this region was observed. There were no signs of improvement.

http://www.healthmantra.com/rotary/hypochorite%20accident.pdf

Permanent mimic musculature and nerve damage caused by sodium hypochlorite: a case report.

The aim of the present in vitro study was to evaluate different restorative concepts for posterior resin composite fillings in terms of internal adaptation and overhang formation. Eighty standard occluso-distal cavities with and without a 1.5-mm bevel were restored in a phantom head using Syntac Classic and Tetric Ceram with and without Tetric Flow as thin lining or Solid Bond and Solitaire with and without FlowLine. The restorations were finished intraorally and afterwards subjected to thermal loading (1150 x +5 degrees C/+55 degrees C) for 24 h. The proximal margins of the original specimens were analyzed for overhangs under a stereo light microscope (100-fold magnification) before and after intraoral control with loupes, including additional polish. Afterwards the teeth were cut longitudinally, replicated, and their internal integrity analyzed under a SEM (200-fold magnification). The combination of flowable and viscous composites resulted in enhanced internal adaptation for both adhesive systems. However, Syntac Classic exhibited superior adaptation characteristics compared with Solid Bond. In terms of overhang formation, the use of flowable materials always led to higher percentages of marginal overhangs in beveled cavities. Higher viscous materials alone resulted in higher percentages of underfilled margins of beveled than box-shaped cavities. It was clear that the use of magnifying glasses during finishing was beneficial for reducing marginal overhangs up to 40%.

Matthias Pelka

Papers

A new screening test for toxicity testing of dental materials.

IPS Empress inlays and onlays after four years--a clinical study.

Elution parameters and HPLC-detection of single components from resin composite.

Permanent mimic musculature and nerve damage caused by sodium hypochlorite: a case report.

Internal adaptation and overhang formation of direct Class II resin composite restorations.