Biomedical subjects

I Heling

Publications and source records attributed to I Heling.

At least 19 recordsLinked to original sources

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↗

PubMed2001

Bactericidal and cytotoxic effects of sodium hypochlorite and sodium dichloroisocyanurate solutions in vitro.

The antimicrobial and cytotoxic effects of sodium hypochlorite (NaOCl) and sodium dichloroisocyanurate (NaDCC) were evaluated and compared in vitro. The minimal inhibitory concentration and minimal bactericidal concentration of NaOCl and NaDCC were tested for Streptococcus sobrinus, Streptococcus salivarius, Enterococcus faecalis, and Streptococcus mutans. The cytotoxic effect was assessed by using human fibroblast tissue culture. Survival rate was assessed by a protein determination method. Results showed that the minimal inhibitory concentration and minimal bactericidal concentration values of NaOCl and NaDCC for the tested bacteria were in a similar range. NaDCC in concentrations higher than 0.02%, and NaOCl in concentrations higher than 0.01% were lethal to fibroblasts. In conclusion it seems that both agents were very effective in killing bacteria, and their cytotoxicity to fibroblasts in tissue culture was similar.

Anti-Infective Agents, Local↗

PubMed2001

The outcome of teeth with periapical periodontitis treated with nonsurgical endodontic treatment: a computerized morphometric study.

OBJECTIVES: This study investigated the prognosis for successful endodontic treatment and the correlation between the size of the periapical lesion, the quality of the root canal treatment, and the type of coronal restoration. METHOD AND MATERIALS: Periapical radiographs of 319 teeth with periapical periodontitis were studied. The area of each lesion was measured before treatment and 1 to 12 years after completion of the endodontic treatment. The measurements were performed using computerized morphometry. RESULTS: In 65.2% of the teeth, the size of the lesion decreased, while in 34.8% of teeth, there was an increase. Lesions larger than 10 mm2 had a greater tendency for healing. CONCLUSION: No significant correlation was found between the quality of root canal treatment, the type of the coronal restoration, and the success rate of the endodontic treatment.

Adolescent↗

PubMed2000

Profile of an orthodontic patient at risk of dental trauma.

Increased overjet and inadequate lip coverage of the maxillary incisors are considered significant risk factors in many clinical studies. The purpose of the present study was to examine this issue of dental injury by actual cephalometric measurements in orthodontic patients. Pretreatment cephalograms (taken with lips in repose) of consecutive patients were used. The patients were allotted to two groups Group T (trauma): 56 patients who had injured their maxillary incisors prior to their orthodontic treatment, mean age at the start of treatment 11.9 years (SD = 1.5); and Group C (control): 98 patients with intact maxillary incisors, mean age at the start of treatment 11.6 years (SD = 1.3). Twelve cephalometric landmarks on the soft and hard tissue profile were identified and digitized and the relevant dental, skeletal and soft tissue measurements recorded. The variables in Groups T and C were compared and their predictive values for possible occurrence of trauma were tested by logistic regression analysis. No statistically significant differences between boys and girls were found. Overjet or maxillary incisor exposure or interlabial gap, each as a single variable, could differentiate between the two groups. Logistic regression analysis indicated that only a small percentage (28.7%) of the dependent variable variation (trauma vs control) can be explained by interlabial gap, gender, upper incisor long axis to facial plane (degree), upper incisor long axis to interlabial gap and overjet.

Cephalometry↗

PubMed2000

Bone-like tissue growth in the root canal of immature permanent teeth after traumatic injuries.

Following a severe traumatic incident to permanent immature teeth, the growth of calcified tissue in the pulp space may occasionally occur. This calcified tissue may be diffuse or in intimate contact with the dentine. It has been suggested that a wide open apex, severe damage to the root sheath, and the absence of infection are only some of the predisposing factors leading to this metaplasia of pulp tissue into bone-like tissue. Five cases are described.

Adolescent↗

PubMed2000

Effect of prefabricated metal post-head design on the retention of various core materials.

Retention of various post heads to core restorative materials is an important factor in the selection of prefabricated post systems and restorative materials for the restoration of endodontically treated teeth. This study examines the retention of a post-core prefabricated system in relation to core material and post-head design. A total of 60 samples were prepared using two different post systems (ParaPost Plus (PP) and ParaPost Unity (PU), with amalgam, composite or glass-ionomer as one of the core materials. The samples were tested using the Instron testing machine. The PP was superior to the PU prefabricated post with respect to the retention of various core materials. Retention values in descending order of magnitude were found to be: composite, amalgam and glass-ionomer (significantly lower). The rhomboid serrated design of PP was superior in retention to the rounded smooth UP system. Composite material proved to be superior in retention, closely followed by amalgam, with glass-ionomer significantly less retentive.

Analysis of Variance↗

PubMed1999

In vitro antimicrobial effect of RC-Prep within dentinal tubules.

The antimicrobial effect of RC-Prep and its components--10% urea peroxide, 15% EDTA, and glycol--were evaluated individually, in vitro, within dentinal tubules. Standardized bovine incisor root specimens that had been infected with either Staphylococcus aureus or Streptococcus peltzer were incubated with each agent for 10 and 45 min. After exposure to the agent, dentin samples were collected from within the lumina using ISO 23 to 31 burs. Dentin powder samples were incubated with bacterial broth, and the amount of bacteria present was assessed by spectrophotometry. All agents tested were more effective in killing bacteria after incubation for 45 min than after 10 min.

Analysis of Variance↗

PubMed1999

The effect of periapical rarefying osteitis on cortical and cancellous bone. A study comparing conventional radiographs with computed tomography.

OBJECTIVE: To determine whether erosion of the cortical plate is necessary for successful radiographic identification of periapical rarefying osteitis. METHODS: Forty-two periapical osteitic lesions were diagnosed from periapical radiographs of 26 patients who were subsequently examined by cross-sectional computed tomography (CT). The relation of the lesions to the buccal and lingual cortical plates was determined and their size measured. RESULTS: The 42 lesions varied in size from 2 - 10 mm. Thirty one (74%) lesions diagnosed on the periapical radiographs were limited on CT to the cancellous bone with no erosion of the cortical plates. The 11 lesions with cortical erosion were randomly located throughout the jaws. Erosion was due to either the eccentric buccal or lingual location of the tooth apex, large size (>6 mm) of the lesion or narrowness of the jaw. CONCLUSIONS: Periapical lesions can be diagnosed from periapical radiographs while they are limited to the cancellous bone and before they have eroded the cortices.

Adolescent↗

PubMed1999

Antibacterial synergistic effect of chlorhexidine and hydrogen peroxide against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus.

Chlorhexidine (CHX) and Hydrogen peroxide (HP) are potent antibacterial agents that are used in controlling dental plaque. However, both agents bear undesired side-effects. We have tested the hypothesis that an antibacterial synergistic effect can occur between the two agents against Streptococcus sobrinus, Streptococcus faecalis and Staphylococcus aureus. We have found that at several combinations of HP and CHX an antibacterial synergistic effect does occur, while at other combinations a on-significant synergism was noticed. No antagonism between the two agents was found in our experimental system. It can be postulated that the mechanism of this synergistic effect is via alteration of the bacterial cell-surface by CHX thereby allowing for an increased amount of HP to penetrate and to react with the intercellular organelles of the bacteria. These results suggest that CHX and HP can be of use in controlling the dental plaque in the oral cavity.

Anti-Infective Agents, Local↗

PubMed1999

In vitro antibacterial effect of RC-Prep components on Streptococcus sobrinus.

The aim of this study was to examine the bacteriostatic and bactericidal effects of the components of RC-Prep: EDTA, urea peroxide and glycol. The minimal inhibitory concentration and the minimal bactericidic concentration of EDTA, urea peroxide and glycol were tested on the viability of Streptococcus sobrinus (S. sobrinus). The combined antibacterial effect of these components was also examined on S. sobrinus. The minimal inhibitory concentration of EDTA was found to be 0.125%, of urea peroxide 0.25%, and of glycol 30%. The minimal bactericidic concentration of EDTA was 0.25%, of urea peroxide 0.5% and of glycol 50%. An antibacterial synergistic effect was found between specific combinations of urea peroxide, EDTA and glycol. No antagonistic effects were found in the various combinations between the components. The antimicrobial effect of the components of RC-Prep was enhanced in specific combinations of the ingredients. This effect might contribute to the intracanal cleansing properties of this medication.

Anti-Infective Agents, Local↗

PubMed1998

Antimicrobial effect of irrigant combinations within dentinal tubules.

The aim of this study was to investigate sodium hypochlorite (with and without EDTA), chlorhexidine, and hydrogen peroxide in varying concentrations when used in sequence or in combination as endodontic irrigants. Sterile saline served as the control. Six standardized bovine incisor root specimens, which had been infected with Enterococcus faecalis (CG 110), were exposed to each solution. Following exposure to the test agents dentine samples were taken from within the lumina using ISO 023 to 035 burs. The dentine powder samples were incubated and the quantity of bacteria present assessed using spectrophotometry. All irrigant regimens were more effective than saline in killing bacteria. Chlorhexidine and sodium hypochlorite were similarly effective. At specific concentrations a synergistic effect was noted when mixtures of chlorhexidine and hydrogen peroxide were under test.

Animals↗

PubMed1996

The antimicrobial effect within dentinal tubules of four root canal sealers.

The aim of this study was to investigate four root canal sealers--Pulp Canal Sealer EWT, Sealapex, AH26, and Ketac-Endo--for their antibacterial effects within dentinal tubules. Sterile saline served as a control. Sixty-six standardized bovine root specimens were infected with Enterococcus faecalis following smear layer removal. The materials were placed in the lumina, and six specimens from each group were stored for 24 h (48 h for AH26) and 7 days, after which dentin samples were taken from within the lumina using ISO 023 to 035 burs. Powder samples were incubated and the quantity of bacteria present assessed using spectrophotometry. All sealers showed antibacterial activity at 24 h, except Ketac-Endo. The activity of Pulp Canal Sealer EWT was similar at 24 h and 7 days. Sealapex had greater antibacterial effect at 7 days than it did at 24 h. The strongest effects were demonstrated by AH26.

Analysis of Variance↗

PubMed1996

Endodontic retreatment of unusually long maxillary central incisors.

Anatomical and morphological variations in teeth may affect the success and prognosis of endodontic therapy. The reported data regarding such variations in the maxillary central incisors are limited. This article presents a case of endodontic retreatment in unusually long maxillary central incisors.

Adolescent↗

PubMed1996

Histochemical analysis of dental hard tissues following bleaching.

The effect of commonly used bleaching materials on the dental hard tissues was tested in extracted human premolars. In each tooth, the apical two-thirds of the root was removed, and the remaining tooth stump was cut longitudinally into two equal segments. The segments were cleaned, dried, and divided into six experimental groups. Each group was treated with one of the following bleaching materials: 30% hydrogen peroxide (HP), 10% carbamide peroxide (CP), sodium perborate (SP), Nu-Smile (NS), Opalescence (Op), and DentlBright (DB). Treatment consisted of immersing the specimens in the respective test material followed by incubation at 37 degrees C for 7 days. The levels of calcium, phosphorus, sulfur, and potassium were measured in the enamel, dentin, and cementum. In the enamel, a significant reduction in the calcium/phosphorus (Ca/P) ratio was found following treatment with HP. In the dentin, a significant reduction in Ca/P ratio was found following treatment with HP,CP, DB, and Op. In the cementum, a significant reduction in the Ca/P ratio was found following treatment with HP, CP, NS, and Op. Changes in sulfur and potassium levels also occurred, but were usually not statistically significant. Significant reduction in sulfur levels occurred only in the cementum following treatment with CP and SP. Sulfur levels increased significantly following treatment with NS. Significant reduction in potassium levels occurred only in the dentin following treatment with CP. It is concluded that bleaching materials may adversely affect the dental hard tissues and should be used with caution.

Borates↗

PubMed1995

Effect of bleaching agents on dentin permeability to Streptococcus faecalis.

Bacterial contamination of dentin may be a contributing factor in the development of bleaching-associated root resorption. In this study, the effect of commonly used bleaching agents on the permeability of dentin tubules to Streptococcus faecalis was evaluated. Sixty extracted bovine incisors were horizontally sectioned apically to the cementoenamel junction. In each tooth, a standard cavity was prepared, the pulp tissue extirpated, and remnants of soft tissue and smear layer were removed. Following rinsing and repeated autoclave sterilization, the teeth were divided into four groups, each treated with one of the following materials: 30% hydrogen peroxide, sodium perborate mixed with 30% hydrogen peroxide, sodium perborate mixed with distilled water, and distilled water alone that served as control. The bleaching agents were sealed in the teeth and incubated at 37 degrees C for 7, 14, and 21 days. At each time interval the bleaching agents were removed and the teeth incubated at 37 degrees C in brain heart infusion infected with S. faecalis. Histological sections were prepared, and the maximal bacterial penetration for each group was measured using a computerized morphometric system. Statistical analysis of the results revealed that teeth treated with either 30% hydrogen peroxide alone or in combination with sodium perborate were significantly more permeable to S. faecalis than those treated with sodium perborate mixed with water (p < 0.0001). Sodium perborate mixed with water did not cause an increase in dentin permeability to S. faecalis and was similar to the water control. In conclusion, it seems that bleaching agents containing hydrogen peroxide in high concentrations may increase bacterial penetration through dentinal tubules.

Analysis of Variance↗

PubMed1995

Mandibular canine with two roots and three root canals.

A rare case of root canal retreatment in a lower canine with two roots and three canals is presented. While the presence of two roots and two canals in one root is not uncommon, the finding of three canals in a lower canine appears not to have been reported previously.

Adult↗

PubMed1995

Efficacy of three cavity liners in eliminating bacteria from infected dentinal tubules.

Three lining materials, Life, Ketac-Bond, and IRM, were investigated for their antibacterial effects within dentinal tubules. Sterile saline served as control. Sixty standardized bovine root specimens were infected with Enterococcus faecalis following smear layer removal. The materials were mixed according to manufacturer's directions and inserted in the canal lumina; additional IRM specimens received a softer than normal mix. Specimens were incubated for 24 hours or 7 days, after which dentinal samples were taken from within the lumina and the numbers of bacteria present were assessed. All the materials had a significant antibacterial effect after 7 days. Life demonstrated a more marked effect at 7 days than at 24 hours. The strongest antibacterial effect at 24 hours was shown by a "soft" mix of IRM. Ketac-Bond demonstrated an increase in antibacterial activity during the experimental period.

Analysis of Variance↗

PubMed1994

Intraligamentary injection of slow-release methylprednisolone for the prevention of pain after endodontic treatment.

The intraligamentary injection of a slow-release steroidal, the anti-inflammatory agent slow-release methylprednisolone (Depomedrol), was compared to a placebo and to an active placebo (Mepivacaine) in preventing postoperative pain after root canal treatment. The results clearly demonstrated that the tested drug significantly reduced the frequency and intensity of postoperative pain sequelae in the experimental set-up.

Adult↗