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Biomedical subjects

N Hochman

Publications and source records attributed to N Hochman.

At least 19 recordsLinked to original sources
PubMed2005

Cranberry juice constituents affect influenza virus adhesion and infectivity.

Cranberry juice contains high molecular weight materials (NDM) that inhibit bacterial adhesion to host cells as well as the co-aggregation of many oral bacteria. Because of its broad-spectrum activity, we investigated NDM's potential for inhibiting influenza virus adhesion to cells, and subsequent infectivity. Hemagglutination (HA) of red blood cells (RBC) caused by representatives of both influenza virus A subtypes (H1N1)and H3N2) and the B type was inhibited by NDM at concentrations of 125 microg/ml or lower, which is at least 20-fold lower than that usually found in cranberry juice. A dose-response effect of NDM on HA was demonstrated. The infectivity of the A and B types was significantly reduced by preincubation with NDM (250 microg/ml), as reflected by the lack of cytopathic effect on Madine-Darby canine kidney (MDCK) cells and the lack of HA activity in the media of infected cells. The effect of NDM was also tested after A or B type viruses were allowed to adsorb to and penetrate the cells. Various levels of reduction in virus tissue culture infective dose TCID50 were observed. The effect was most pronounced when NDM was added several times to the infected MDCK cells. Our cumulative findings indicate that the inhibitory effect of NDM on influenza virus adhesion and infectivity may have a therapeutic potential.

Animals↗
PubMed2003

A clinical and radiographic evaluation of fixed partial dentures (FPDs) prepared by dental school students: a retrospective study.

In recent years, there has been an increasing interest in fixed partial dentures (FPD) quality, expected lifetime and possible reasons for failure. This study probed the FPD success rate and the relationship among various factors and their effect on FPD failure. Patients treated by dental students under supervision and installed FPDs were examined clinically and radiographically. A total of 247 FPDs were evaluated after a mean service period of 6.3 years (ranging from 1 to 25 years) after cementation. Caries was found to be the most frequent cause of failure and non-vital abutments decreased survival rates.

Adult↗
PubMed2003

Effect of design of pre-fabricated posts and post heads on the retention of various cements and core materials.

The retention of new Para Post (PP) rounded undercut post head (PP-XT) was compared with the conventional flattened head (PP-P), using amalgam Dentacore and Synergy composite as core materials. The retention of the posts PP (passive serrated), PP-P (passive serrated with venting channels), PP-XP (passive, raised diamond-style pattern) and PP-XT (threaded on the coronal portion, and passive, raised diamond-shaped pattern on the apical portion), cemented with zinc phosphate cement (ZPC) or Duo Cement to extracted teeth, was evaluated. Tensile strength plots were recorded using an Instron instrument, while pulling the post and core in opposite directions. The following conclusions were drawn from this study: (i) The round undercut PP-XT head was more retentive than the PP-P head with both core materials. (ii) Amalgam was more retentive than Synergy with both head designs. (iii) PP-XT was the most retentive post to extracted tooth canals and PP-XP was the least retentive with either ZPC or Duo Cement. Post retention with (iv) ZPC in decreasing order of magnitude: PP-XT > PP-P > PP > PP-XP; and with Duo Cement: PP-XT > PP > PP-P > PP-XP - ZPC exhibited the highest retention of cemented posts.

Bisphenol A-Glycidyl Methacrylate↗
PubMed2003

Resin-bonded fixed partial denture retention: a retrospective 13-year follow-up.

A total of 51 resin-bonded fixed partial dentures (RBFPDs) were inserted under controlled clinical conditions and evaluated over a period of 13 years. Three levels of survival were defined: complete survival (no debonding); functional survival (loss of retention on one occasion with rebonding of the original RBFPD); and multiple survival (loss of retention on several occasions with rebonding of the original RBFPD). The effect of the aetiology, location (anterior/posterior or maxillary/mandibulary) and number of units of the missing tooth on RBFPD survival rates were investigated. The mean survival times and confidence levels were determined for each survival category, using the Kaplan-Meier procedure. The relative risks were calculated by the Cox regression procedure. The overall complete survival level of the study population at the end of the follow-up period was 85 months +/- 13%. Rebonding the RBFPDs once increased the overall functional survival rate to 112 months +/- 10% and multiple rebonding led to a further increase to 131 months +/- 8%. The RBFPD placement under conditions of good periodontal support in which orthodontic treatment was not required, such as trauma among other factors, showed significantly higher survival rates than those placed after periodontal or orthodontic treatment. This indicates that, under both these conditions, RBFPDs may serve as long-term or semi-permanent restorations.

Adolescent↗
PubMed2001

Is herpes simplex virus associated with pulp/periapical inflammation?

OBJECTIVES: This study focuses on the detection of herpes simplex virus (HSV) DNA in dental pulp and inflamed periapical tissue. STUDY DESIGN: Dental pulp tissue (vital and necrotic) and periapical tissue samples were collected under strictly sterile conditions and examined for the presence of HSV DNA. Saliva samples were also examined for the presence of the viral DNA. The polymerase chain reaction assay was used to detect viral DNA. Blood samples were collected, and the enzyme-linked immunosorbent assay (ELISA) for immunoglobulin G (IgG) and immunoglobulin M (IgM) antibodies against HSV was carried out. RESULTS: According to the ELISA test, 19 of the 23 blood samples were IgG-positive and IgM-negative to HSV, whereas 4 were IgG-negative and IgM-negative. HSV DNA was not detected in the tissue and the saliva samples tested. CONCLUSION: HSV is not present and therefore is probably not involved in the pathology of tooth neural tissue.

Adolescent↗
PubMed1999

New all-ceramic indirect post-and-core system.

The increasing demand for highly esthetic, biocompatible posts and cores has led to the development of metal-free, post-and-core systems. This article describes and evaluates an indirect method for the fabrication of an all-ceramic post and core.

Aluminum Silicates↗
PubMed1998

Esthetic considerations in restoring endodontically treated teeth with posts and cores.

Posts and cores are often required for the restoration of endodontically treated teeth. Many methods for making post-and-core reconstructions have been described. With the increased use of all-ceramic systems for esthetic tooth restorations, there is a need for esthetic core reconstructions. This article describes several methods for fabricating esthetic posts and cores.

Dental Porcelain↗
PubMed1998

Antibodies to cytomegalo and Epstein-Barr viruses in human saliva and gingival fluid.

The prevalence of antibodies to EBV and CMV was studied in 34 samples of whole saliva and gingival crevicular fluids (GCF) obtained from clinically healthy volunteers and compared to the corresponding antibodies present in the serum of each individual. Higher prevalence of serum antibodies was found to EBV (85.2%) than to CMV (64.7%) (P < 0.04). The percentage of saliva samples containing IgG and/or IgA antibodies was not significantly different for the two viruses (79.4% for EBV and 58.8% for CMV). However, in the GCF the percentage to EBV was lower-32.3% as compared to 70.5% for CMV (P < 0.002). The prevalence of CMV in serum saliva and GCF was similar. However, while in the saliva similar levels of IgG and IgA were found, in the GCF IgA prevails. The picture for EBV is different: a similar percentage of antibodies was noticed in serum and saliva, but it was significantly lower in the GCF. However, antibodies to EBV were mostly IgA both in the saliva and the GCF. Although a similar number of samples were positive to both viruses in the saliva, the IgA response to EBV was higher than to CMV (P < 0.05), while in GCF IgA response was higher to CMV (P < 0.05). Passive transudation rather than active transport of plasma-derived Ig is probably responsible for the presence of IgG, while the IgA found in saliva and GCF is derived from local synthesis by plasma cells rather than from selective transport from blood.

Adult↗
PubMed1998

Comparative clinical evaluation of removable partial dentures made from impressions with different materials.

Impressions for removable partial dentures (RPDs) should provide an accurate and detailed record of the teeth and soft tissues. Removable partial denture casts should be exact replicas of the mouth to ensure that RPD frameworks fit accurately and are fully adjusted to oral structures. A comparative clinical evaluation was performed on the oral fit of RPDs made from impressions with either irreversible hydrocolloid (alginate) or condensation silicone. The difference between the two groups was found to be statistically significant.

Alginates↗
PubMed1997

Alternative method of conservative esthetic treatment for gingival recession.

The health and appearance of gingival tissue play an essential role in esthetics. The esthetic function of the tissue is enhanced when it frames the restoration. With gingival recession, the effect of natural gingiva is created with pink composites or ceramics on the cervical part of the crown, as described in this clinical report. This goal depends on the absence of adverse effects on the color, shape, and health of the surrounding tissue. The new composites are more color stable and wear resistant, and the latest generation of dental bonding agents allows the bonding of composites to dentin, various metals, and porcelain. The application of soft-tissue colored composite on dentin cementum, enamel, or porcelain is a good solution for correcting gingival recessions.

Acid Etching, Dental↗
PubMed1997

Hypersensitivity to methyl methacrylate: mode of treatment.

This article describes the treatment of a patient who experienced a delayed hypersensitivity reaction associated with acrylic resin. Patch testing revealed an allergy to methyl methacrylate monomer. Patients with a known or suspected allergy of this type should be treated by alternative methods. Dental procedures in which negligible contact of the oral mucosa with methyl methacrylate are presented.

Acrylic Resins↗
PubMed1997

Laminate veneer provisionalisation.

The advantages of provisional laminate veneers are described. Provisional coverage is justified both from the aesthetic and functional viewpoints. Both direct and indirect methods for fabricating provisional laminate veneers are outlined. Among the direct methods for Laminate Veneer fabrication, the use of the preoperative impression, preformed polycarbonate crowns, and vacuform matrix are presented. These methods are quick, fabrication is easy, and the results are highly aesthetic with good patient comfort and satisfaction.

Dental Restoration, Temporary↗
PubMed1996

Skeletal and functional effects of treatment for unilateral posterior crossbite.

Unilateral posterior crossbite (UPXB) is a common malocclusion, frequently presenting a lower midline deviation, accompanied by Class II subdivision relationships in final closure and a very high prevalence of the reverse sequencing (RS) pattern of jaw movement. These features often persist even after the elimination of the crossbite. The purpose of the present study was to examine in detail the morphologic, skeletal, and functional effects of the treatment for this malocclusion category. The experimental group consisted of 24 children in the mixed dentition stage with UPXB who were treated with removable expansion plates and a control group of 10 age-matched children with normal occlusion. Longitudinal follow-up revealed a stable dental maxillary arch expansion of at least 1.5 mm but a complete elimination of crossbite in only 50% of the cases. The frequent persistence of Class II subdivision relations and lower midline deviation that were not due to functional mandibular shift was striking. The pretreatment posteroanterior (P-A) cephalograms indicated reduced facial and maxillary widths. After treatment, the achieved maxillary width increase was greater than expected with normal growth. Longitudinal assessment of the mandibular movement response revealed by the electrognathograph showed a high prevalence of RS, which was reduced after treatment. In conclusion, (1) a higher than expected prevalence of skeletal transverse aberrations at the maxillary and zygomatic levels were found in the UPXB group; (2) the removable expansion appliance induces transverse growth of the maxilla; and (3) an inherent pattern of jaw movement is characteristic to the UPXB and does not change significantly with orthodontic treatment.

Case-Control Studies↗
PubMed1996

Physiologic occlusion vs pathologic occlusion and rationale for treatment.

Treatment concepts in dentistry are generally based on a preconceived normal state derived from clinical observation and theories rather than scientific evidence. Before treatment is proposed, the clinician should observe physiologic signs and symptoms to determine the presence of a particular pathology. This article presents different theories of occlusion, diagnostic characteristics that can be used to distinguish between physiologic occlusion and pathologic occlusion requiring treatment, and guidelines for reconstructive occlusal therapy.

Adult↗