Uri Zilberman

Absorption of Nickel, Chromium, and Iron by the Root Surface of Primary Molars Covered with Stainless Steel Crowns

Objective. The purpose of this study was to analyze the absorption of metal ions released from stainless steel crowns by root surface of primary molars. Study Design. Laboratory research: The study included 34 primary molars, exfoliated or extracted during routine dental treatment. 17 molars were covered with stainless-steel crowns for more than two years and compared to 17 intact primary molars. Chemical content of the mesial or distal root surface, 1 mm apically to the crown or the cemento-enamel junction (CEJ), was analyzed. An energy dispersive X-ray spectrometer (EDS) was used for chemical analysis. Results. Higher amounts of nickel, chromium, and iron (5-6 times) were found in the cementum of molars covered with stainless-steel crowns compared to intact molars. The differences between groups were highly significant (P < .001). Significance. Stainless-steel crowns release nickel, chromium, and iron in oral environment, and the ions are absorbed by the primary molars roots. The additional burden of allergenic metals should be reduced if possible.

Enamel development in primary molars from children with familial dysautonomia

OBJECTIVES Familial dysautonomia (FD) is an autosomal recessive disorder, classified as a hereditary sensory and autonomic neuropathy type III, associated with growth defects affecting postnatal development. This study analysed prenatal and postnatal enamel development and postnatal calcification in upper second primary molars from FD children in comparison with healthy controls. The postnatal enamel of FD was also examined histologically for manifestation of growth insults. DESIGN The analyses were carried out on two ground sections, connecting buccal and palatinal cusp tips of mesial and distal cusps. The measurements included apical location of neonatal line, width and percentage of prenatal enamel. Chemical analyses were performed using an energy dispersive X-ray spectrometer. RESULTS The prenatal proliferative phase and prenatal apposition rate of enamel were faster on the distal cusps in FD. The postnatal enamel thickness was similar in both groups. The phosphate content of FD teeth was significantly higher and the Ca/P ratio was significantly lower. Postnatal traumatic lines were observed in all FD children and in only one healthy child. CONCLUSIONS FD upper primary second molars showed thicker prenatal enamel formation in comparison to healthy and other syndromes and better mineralisation. All FD primary molars showed large number of postnatal traumatic lines, implicating severe traumatic episodes during the first year of life.

Acid resistance of the enamel in primary second molars from children with down syndrome and cerebral palsy.

Objectives: This study was carried out to evaluate the extent of differences in mineralization of inner and outer enamel of the lower primary second molars of children with Down syndrome (DS) and Cerebral Palsy (CP) as revealed by acid treatment of exfoliated teeth. The results were compared to those obtained from a control group of healthy children. Methods: The sample included 4 mandibular second molars from each group. On each tooth, a thin section was cut, bisecting the mesial cusps. The analysis was carried out on the mesio-buccal cusps. Atomic force microscopy (AMF) was used to analyze the morphological structure of the dental enamel after 10 sec of 0.1 mol% citric acid treatment. The measurements were performed on 3 points in the enamel close to the outer surface and 3 points in the enamel close to the dentin. The differences between groups were analyzed using Mann Whitney tests. Results: In controls and CP teeth the outer enamel was more resistant to etching than the inner enamel. In DS teeth both outer and inner enamel showed similar results for all parameters. Between group comparisons showed that roughness values were significantly higher (P<0.01) in DS teeth than in either controls or CP teeth. No significant differences were found between CP and control teeth. Conclusions: The higher values obtained for DS enamel reflect increased solubility of the enamel to acid relative to controls and CP teeth together with irregularity of the organic matrix. The practical importance of the results is that DS primary molars needs reduced etching time when prepared for pit and fissure sealants or composite/compomer restorations.

A 3000 year old case of an unusual dental lesion: Pre-eruptive intracoronal resorption

OBJECTIVE To determine the cause of a large dental lesion, tentatively identified as a case of pre-eruptive intra-coronal resorption (PEIR), in the permanent second mandibular molar of a young individual from an Iron Age cemetery at Tel Erani (Israel), dated to ca. 3000 years B.P. The provisional diagnosis was based on the massive size of the lesion in a young individual in whom the adjacent teeth were caries-free and showed no visible enamel defects. DESIGN The lower molars of Tel Erani on the affected side were radiographed and compared to radiographs of a modern clinical case of PEIR treated by one of us (U.Z) and the internal structure and mineral content of the lesion examined in detail using energy-dispersive X-ray spectroscopy (EDS). RESULTS The Tel Erani specimen closely resembled the modern clinical case of PEIR. Moreover, both cases occurred in young individuals in whom the adjacent teeth were caries-free. Examination with SEM revealed absence of dentine in the affected tooth from Tel Erani, together with changes in structure and mineral content characteristic of resorption. CONCLUSIONS Our study shows that the changes found in the lower second molar of the 3000 year old mandible from Tel Erani are characteristic of PEIR and demonstrate the antiquity of this condition.

Local Anesthesia in Pediatric Dentistry-How Much is Enough?

Aim: To evaluate the doses of local anesthesia (LA) during routine dental treatment of children, used by specialists in pediatric dentistry (SPDs), residents in pediatric dentistry (RPDs) and general practitioners (GPs) and suggest recommendations for using minimal doses. Study design: A prospective research. 120 LA cartridges were collected after provided dental treatment of children by 4 specialists (SPD-55 cartridges), 5 residents in pediatric dentistry (RPD-43 cartridges) and 3 general practitioners (GPs-22 cartridges).The doses of the used solution were measured by deducting the remains in the cartridge from the original 1.8ml. Results: A significantly lower dose of LA solution was used by specialists and residents compared to GPs, (0.786/0.746 ml ± 0.4 Vs.1.65 ml ± 0.3, P<0.001). Discussion: LA guidelines intend to achieve optimal effect, increase safety and reduce side effects. Various dentists have different training and experience, as well as personality and habits, which may affect their use of LA. This prospective study evaluated these factors. Conclusions: The dentist training is a valuable predictor for the LA dose being injected to a child during dental treatment. The mean dose used in the study by specialists and residents was less than half compared to GPs, but effective enough for successful dental treatment, regardless of the number of treated teeth, the site, the type of the treatment and the patients age. We suggest increasing the awareness of using minimal effective dose of LA in pediatric dentistry.

The Influence of Zinc Oxide Eugenol (ZOE) and Glass Ionomer (GI) Base Materials on the Microhardness of Various Composite and GI Restorative Materials

Objective: Re-examining the well accepted concept that Zinc-Oxide-Eugenol bases (ZOE) have a negative effect on composite restoration materials microhardness, in light of the advancement in composite materials and newer publications. Methods: Five modern composite restoration materials were used, including hybrid (Xtra-fill and Z250), micro-fill hybrid (G-aenial and Gradia-direct) and methacrylate-free restorative material (Silorane- oxirane). Two base materials were used IRM (ZOE-base) and Fuji-IX (GI-base). Samples were made using a designed mold, in which composite discs were cured on top and in close relation to base materials. Micro-hardness testing was performed using a DMH-2 microhardness tester utilizing the Knoop method. Results: Statistic analysis demonstrated significantly better microhardness of three composite materials when IRM was used as base in comparison to control (G-aenial, Gradia direct and Filtek silorane), and no differences in two materials (Filtek universal Z250 and Voco Xtra-fil). Fuji-IX bases showed a significant positive effect on the microhardness of four composite materials, and a negative effect on one material (Voco Xtra-fill). In comparison with other tested restoration materials, both Voco Xtra-fill and Fuji-IX showed higher microhardness results (P<0.05). Significance: Related to microhardness, both ZOE and GI bases can be used safely as bases under composite restorations. The results of this study together with the results published recently showed that the concept of not using ZOE or GI bases under composite must be reconsidered. Fuji IX showed microhardness results similar to the best composite material and therefore it can be used as a restorative material.