Microleakage comparison of dentin bonding systems with glass ionomer.

Glass-ionomer cements have been suggested as substitutes for dentin-bonded composites. This investigation was designed to compare microleakage of glass-ionomer restorations with that of dentin-bonded composite restorations. Eighty extracted human molars were used in this study. Class V cavities were prepared on the mesial and distal surfaces of each tooth. The distal cavities were restored with Ketac-Fil Glass Ionomer (ESPE). The mesial cavities were divided into four groups and treated with four different dentin bonding systems: Gluma (Columbus Dental), Tenure (two-part powder system; second version, Den-Mat), Scotchbond 2 (3M), and an experimental ferric oxalate system. The commercial materials were placed according to the manufacturers' instructions. The teeth were then thermocycled 3800 cycles between 5 degrees C and 55 degrees C, subjected to silver nitrate staining, and sectioned for microleakage evaluation by three evaluators on a scale of 0 to 4. The ferric oxalate system exhibited significantly less microleakage (median score = 1; Wilcoxon paired testing, p = 0.01) than the glass ionomer (median score = 3). The other dentin bonding systems were similar in microleakage to the glass ionomer (median score = 3).     

Comparison of conventional root canal obturation techniques with Thermafil obturators.

This study compared microleakage of Thermafil Obturators to the single cone technique in Lexan blocks simulating root canals (n = 20) stained with Prussian blue dye. The microleakage of Thermafil and laterally condensed extracted human teeth was also investigated after the teeth were stained with India ink or Prussian blue dye over 1- or 2-wk dye immersion periods. In Lexan blocks there was no statistical difference in mean leakage between the single cone technique and Thermafil. Teeth with Thermafil Obturators exhibited greater leakage than those with the lateral condensation. Greater leakage was also seen where India ink was used. Dye immersion time did not have a significant influence on leakage scores. The combination of India ink with Thermafil demonstrated the greatest average leakage. This study demonstrated that Lexan canal simulating blocks do not mimic extracted human teeth for evaluating microleakage.     

Comparison of microleakage of experimental and selected commercially available bonding system

The microleakages of composite restorations bonded with two commercial and two experimental systems were observed. A high-viscosity condensable composite and a low-viscosity composite were used as the restorative materials. The bonding systems used were two widely accepted commercial brands and two experimental systems, one containing ferric oxalate and the other aluminum oxalate. Restorations were placed in cavities prepared in extracted human teeth and treated with the various bonding systems. These restorations were stored in 37 degrees C water for 24 hours and then polished. The restored teeth were subjected to seven days of thermocycling (5 degrees C-55 degrees C for 540 cycles per day). Microleakage was detected and scored from 0-4 according to the degree of stain penetration. The experimental systems had lower scores than the commercial systems. The high-viscosity composite restorations had microleakage scores higher than those of the lower-viscosity composite restorations.     

Bonding to tooth structure: clinical and biological considerations

Marginal leakage of tooth restorations is a problem well known to dental practitioners and researchers. The development of agents that provide strong and stable adhesive bonds to both dentine and enamel in the oral environment is a challenge to scientists. The critical area in resin restorations is at the gingival margin where the resin is in apposition to dentine and/or cementum. Therefore, investigations into dentine bonding have been undertaken over the past 20 years. The evaluation of bonding agents includes studies in vitro to investigate their ability to aid the control of microleakage. The biological safety of bonding agents is also very important. Pulpal response to these agents is useful in biological evaluation. Animal studies on the pulpal response of available bonding agents have been reported recently. Precise evaluation criteria have been employed on a limited basis. Long-term clinical studies are now necessary to evaluate the stability of the commercially available bonding agents that have been histologically and biologically evaluated.     

Influence of osteoporosis on the oral health of menopausal women

This article presents current research data that describe the etiology and prevalence of factors associated with osteoporosis and its manifestations in the oral cavity. To educate their patients, dentists should be knowledgeable about the oral manifestations of osteoporosis and should collaborate with other health care providers to reduce the possible destructive effects of osteoporosis on their patients' oral health.     

Microleakage comparison of apical seal of plastic versus metal Thermafil root canal obturators.

This study compared the apical seal of plastic versus metal Thermafil obturators in extracted human teeth. The obturated teeth were evaluated radiographically for the extent and adaptation of the filling obturator. No difference was seen between plastic and metal for over- or underfilling. Voids were seen more often in smaller sizes of both plastic and metal obturators. Obturated teeth were stained in India ink, decalcified, and cleared. Microleakage evaluation of the transparent teeth showed no statistical difference between metal and plastic obturators.     

Dilaceration of permanent upper lateral incisors: frequency, direction, and endodontic treatment implications

A sample of 480 extracted permanent upper lateral incisors was visually examined and the direction of dilaceration was recorded. It was found that 52.1 percent of the roots of these teeth were distolabially dilacerated. Analysis of radiographs of another sample of 442 endodontically treated teeth revealed that distolabial dilaceration occurred in 52 percent of the cases. It is proposed that oversight of the distolabial direction of root dilaceration of upper lateral incisors can be a contributing factor in the failure of endodontic treatment of these teeth.     

Genetic Testing in Egyptian Patients with Inborn Errors of Immunity: a Single-Center Experience

Background

Inborn errors of immunity (IEI) are a group of heterogeneous disorders with geographic and ethnic diversities. Although IEI are common in Egypt, genetic diagnosis is limited due to financial restrictions. This study aims to characterize the genetic spectrum of IEI patients in Egypt and highlights the adaptation of the molecular diagnostic methods to a resource-limited setting.

Methods

Genetic material from 504 patients was studied, and proper diagnosis was achieved in 282 patients from 246 families. Mutational analysis was done by Sanger sequencing, next-generation sequencing (NGS) targeting customized genes panels, and whole-exome sequencing (WES) according to the patients’ phenotypes and availability of genetic testing.

Results

A total of 194 variants involving 72 different genes were detected with RAG1/2 genes being the most encountered followed by DOCK8, CYBA, LRBA, NCF1, and JAK3. Autosomal recessive (AR) inheritance was detected in 233/282 patients (82.6%), X-linked (XL) recessive inheritance in 32/282 patients (11.3%), and autosomal dominant (AD) inheritance in 18/282 patients (6.4%), reflecting the impact of consanguineous marriages on the prevalence of different modes of inheritance and the distribution of the various IEI disorders.

Conclusion

The study showed that a combination of Sanger sequencing in selected patients associated with targeted NGS or WES in other patients is an effective diagnostic strategy for IEI diagnosis in countries with limited diagnostic resources. Molecular testing can be used to validate other nonexpensive laboratory techniques that help to reach definitive diagnosis and help in genetic counseling and taking proper therapeutic decisions including stem cell transplantation or gene therapy.

     

Pulpal response to tricalcium phosphate as a capping agent

The purpose of this study was to evaluate tricalcium phosphate (TCP) as a pulp-capping agent. Two adult male beagle dogs were used for this investigation. Class I cavities were prepared in the posterior teeth and Class V cavities in the anterior teeth. With the use of a rubber dam and high speed with water coolant, minimal pulp exposures were created in both the experimental and control teeth, by means of a 1/2 round bur. Zinc oxide-eugenol was the temporary filling material used to restore all cavities. In each dog, five teeth served as control and were capped with the use of calcium hydroxide. In one dog, 10 teeth from two quadrants were capped with the tested material (TCP). In the other dog, 11 teeth were capped with TCP. Four teeth from the fourth quadrant in each dog were capped with a mixture of calcium hydroxide and TCP in a ratio of 1:1 by weight (50/50 group.) The two dogs were killed after 70 days. The histologic evaluation of the response to the capping agents and at the exposure site was recorded. A total of 39 teeth were evaluated in this study. It was found that TCP as a capping agent precipitated the highest mean inflammatory response and also demonstrated the highest percentage of reparative dentin formation.