PubMed Health⌕ Search

Biomedical subjects

P V Abbott

Publications and source records attributed to P V Abbott.

18 recordsLinked to original sources
PubMed1992

Apical dye penetration with four root canal sealers and gutta-percha using longitudinal sectioning.

The purpose of this study was to compare the level of apical dye penetration when different sealers were used with lateral condensation of gutta-percha. Fifty teeth with single root canals were biomechanically prepared using the step-back technique and irrigation with 15% ethylenediaminetetraacetic acid with cetrimide and 1% NaOCl solutions. The teeth were divided into five groups of 10 teeth each. The control group root canals were filled with laterally condensed gutta-percha without sealer and the other four groups were filled with laterally condensed gutta-percha and either Apexit, Sealapex, Tubli-Seal, or AH-26 sealer. After storage in 100% humidity at 37 degrees C for 48 h, the root surfaces were coated with nail varnish (except at the apex), placed in 2% methylene blue dye solution, and centrifuged at 30 x g for 3 min. The roots were sectioned longitudinally to determine the following mean levels of dye penetration: AH-26, 0.48 mm; Apexit, 1.33 mm; Sealapex, 4.59 mm; Tubli-Seal, 5.58 mm; and gutta-percha alone, 7.99 mm. This study demonstrated that a root canal sealer should be used in conjunction with laterally condensed gutta-percha and that AH-26 sealer had significantly less dye penetration than the other three sealers while Apexit had significantly less dye penetration than Sealapex and Tubli-Seal. There was no significant difference between Sealapex and Tubli-Seal.

Analysis of Variance↗
PubMed1992

Systemic release of corticosteroids following intra-dental use.

Concern has been expressed in the past that the use of corticosteroids within root canal medicaments or pulp capping agents may lead to deleterious systemic effects. Calculations of the highest possible amounts that could be used, plus an analysis of the release and diffusion characteristics, and comparisons with known endogenous levels of corticosteroids, reveal that the intradental use of Ledermix paste and Ledermix cement is unlikely to result in any systemic side-effects.

Demeclocycline↗
PubMed1992

A five-year study of Hydron root canal fillings.

A prospective clinical and radiographic study was conducted in order to compare Hydron and laterally condensed gutta-percha/AH-26 root canal fillings. Paralleling technique periapical radiographs were taken preoperatively, postoperatively and at recall appointments at post-treatment intervals of 6 months, 1 year, 2 years, 3 years and 5 years. Clinical examination at the recall appointments revealed no adverse signs or symptoms amongst all the patients who attended (mean attendance 44.5% at each interval). Radiographs were scored according to the periapical status of the treated root, and comparable bone healing rates were observed between the two root-filling materials. Among the patients attending recall appointments, there were no radiographic signs of failure of any of the 39 gutta-percha/AH-26 root canal fillings. However, three of the 35 canals filled with Hydron were classified as failures, and four required further assessment after the 5-year recall appointment. This study indicated that Hydron and gutta-percha/AH-26 root canal fillings were well accepted but, on the basis of radiographic assessment, success with gutta-percha/AH-26 was more predictable.

Bismuth↗
PubMed1992

Traumatic bone cyst: case report.

The traumatic bone cyst is a lesion whose aetiology and pathogenesis have not been conclusively established. There are several theories and names for this lesion and various forms of management have been reported in the literature. This report outlines the clinical and radiographic findings associated with a case of a traumatic bone cyst. Laboratory investigations were also carried out and their findings are reported. This case was treated jointly by the endodontic and oral surgery departments of an institution and demonstrates the need for close follow-up from both departments. In particular, the endodontic aspects of monitoring the pulp status of teeth in the region of such a bone lesion are emphasised.

Adolescent↗
PubMed1991

A comparative study of the apical leakage of four root canal sealers and laterally condensed gutta-percha.

Previous studies have shown that lateral condensation of gutta-percha and sealer can provide an adequate apical seal. The purpose of this study was to compare the level of apical dye penetration when different sealers were used. One-hundred twenty-five teeth with single root canals were biomechanically prepared using the step-back technique and irrigation with EDTAC and 1% NaOCl solutions. The teeth were divided into five groups of 25 teeth each. The control group root canals were filled with laterally condensed gutta-percha and no sealer and the other four groups were filled with laterally condensed gutta-percha and either Apexit, Sealapex, Tubli-Seal, or AH26 sealer. After storage in 100% humidity at 37 degrees C for 48 h, the root surfaces were coated with nail varnish (except at the apex) and placed in 2% methylene blue dye solution and centrifuged at 3 x g for 3 min. The roots were sectioned transversely at 1-mm intervals to determine the following mean levels of dye penetrations: Apexit, 1.67 mm; Sealapex, 2.28 mm; Tubli-Seal, 1.95 mm; AH26, 0.82 mm; and gutta-percha alone, 8.37 mm. This study demonstrated that a root canal sealer should be used in conjunction with laterally condensed gutta-percha and that AH26 sealer provides a significantly better apical seal than the other sealers.

Bismuth↗
PubMed1991

An SEM study of the effects of different irrigation sequences and ultrasonics.

The root canals of 30 extracted human teeth with single canals were prepared biomechanically with hand instruments using a flaring technique. Three different irrigation regimes were used, with and without ultrasonic activation of a root canal file. The six irrigation sequences used in this study were as follows: Savlon, Savlon with ultrasound, EDTAC/NaOCl/EDTAC, EDTAC/NaOCl/EDTAC with ultrasound, NaOCl/EDTAC/NaOCl, and NaOCl/EDTAC/NaOCl with ultrasound. Scanning electron microscopic (SEM) examination of the prepared root canal walls showed a complete smear layer when Savlon was used. Ultrasound reduced the amount of smear with Savlon, but did not do so significantly with the other irrigation regimes. The most effective irrigation regime for removing smear layer and other debris was EDTAC/NaOCl/EDTAC. In all groups there was a significant decrease in cleaning efficiency as the apical end of the canal was approached.

Cetrimonium Compounds↗
PubMed1991

Self-replantation of an avulsed tooth: 30-year follow-up.

A 42-year-old man had been previously hit in the mouth when he was 12 years old, and the upper left central incisor was completely avulsed. The patient immediately replanted the tooth and did not seek any dental treatment. After 28 years he noticed discoloration and abscess formation. Root canal treatment was performed, and the tooth has remained in a stable, functional position.

Adult↗
PubMed1991

Entrapped air and its effects on dye penetration of voids.

This study was conducted to determine the effect of entrapped air on the ability of methylene blue dye to penetrate known and measurable voids. Thirty six capillary tubes were sealed at one end and had standardized voids created within the lumen. Three equal groups of 12 test specimens and 4 controls were subjected to dye penetration by the methods of passive immersion for 7 days, centrifuging at 3,000 rpm for 5 minutes and immersion in a vacuum of 26 mm of mercury for 5 minutes. Measurement of linear dye penetration was made by removing shavings from the sealed end until dye could be observed. Negative controls showed no dye penetration and positive controls showed complete penetration. The vacuum method showed 100% penetration in all cases, while centrifuging had a mean of 91.7 /+ 8.7% penetration and passive immersion had a mean of 20.7 +/- 5.4% penetration. This study demonstrates that passive dye leakage studies are unreliable and very variable. The vacuum method whereby all entrapped air is removed is the most reliable method for dye penetration studies.

Air↗
PubMed1991

Recognition and prevention of failures in clinical dentistry. Endodontics.

There are many factors that can contribute to endodontic failure, but the major factor that will be associated with almost every failure is the presence of bacteria. Treatment procedures must include techniques that will remove the bacteria that are already present and then prevent further bacterial ingress. Failures can usually be recognized by thorough clinical and radiographic examinations. They can be prevented by careful case selection and by following the accepted standard endodontic procedures and not deviating from these for the sake of expediency. This paper provides an overview of the factors affecting endodontic success and discusses methods used to recognize and prevent failures.

Humans↗
PubMed1990

Antibiotics and endodontics.

Antibiotics can be used as an adjunct to endodontic treatment in a number of ways--locally, systemically and prophylactically. The local or intra-canal use of antibiotics in the form of medicaments is common. However, the commercially available agents for this purpose may not be the ideal mixtures. Systemic antibiotics should be restricted to patients who have local signs of infection, malaise and elevated body temperature. Prophylactic use of antibiotics has been recommended for patients 'at risk' of infective endocarditis, in some pre-surgical situations and following avulsion and replantation of teeth. The tendency towards indiscriminate antibiotic use should be discouraged. The use of broad spectrum drugs should be restricted so that these medications remain effective in serious situations.

Anti-Bacterial Agents↗
PubMed1990

Medicaments: aids to success in endodontics. Part 2. Clinical recommendations.

In order to predictably achieve bacteria-free root canal systems, especially in pulpless teeth, it is necessary to use intra-canal medicaments. Medicaments can also be used to influence the peri-radicular response to endodontic treatment. Consideration of a material's therapeutic action must be made when selecting a medicament for any pathological condition. In general, only two commercial preparations satisfy the general requirements for root canal medicaments. Guidelines and the rationale for the use of these preparations are presented.

Humans↗
PubMed1990

Medicaments: aids to success in endodontics. Part 1. A review of the literature.

Bacteria play a major role in pulpal and periapical disease. They are capable of surviving in dentinal tubules and other canal ramifications that are inaccessible to mechanical instrumentation and irrigation. In order to predictably achieve bacteria-free root canal systems, especially in pulpless teeth, it is necessary to use intra-canal medicaments. These medicaments must be capable of destroying bacteria, reducing inflammation and stimulating hard tissue formation whilst not being toxic to the host tissues. Consideration of a material's therapeutic action must be made when selecting a medicament for any pathological condition. Many of the commercial preparations do not satisfy the requirements for the ideal root canal medicament.

Bacteria↗
PubMed1989

The release and diffusion through human coronal dentine in vitro of triamcinolone and demeclocycline from Ledermix paste.

Crowns from freshly extracted human third molar teeth were used to quantify the release and diffusion of corticosteroid and antibiotic tracer molecules from Ledermix paste used as an indirect pulp-capping agent. These molecules readily diffused through dentine and reached a peak rate of diffusion at 2 h. The rate then decreased exponentially with time. The concentrations of the drugs in the dentine were calculated; this showed that a gradient existed from the cavity floor to the pulp space. The data obtained appeared to have clinical relevance and helped explain the therapeutic benefits of this medicament when used as an indirect pulp-capping agent.

Adolescent↗
PubMed1989

Barriers to diffusion of Ledermix paste in radicular dentine.

Freshly extracted human single-rooted teeth with a single root canal were used to study the effects of 2 irrigation regimens and the effect of cementum on the diffusion of corticosteroid and antibiotic tracer molecules from Ledermix paste placed in the pulp space. An irrigation regime that combined the use of 15% EDTAC and 1% NaOCl resulted in a significant increase in the permeation of the trace molecules through dentine compared with teeth that were irrigated with Savlon solution. Mechanical removal of the cementum also resulted in a significant increase in the permeation of the trace molecules. This study demonstrated that neither the smear layer nor the cementum were complete barriers to diffusion. The data obtained appeared to be of clinical relevance and provided further understanding of the dynamics of drugs in tooth roots.

Adult↗
PubMed1989

Effects of combining Ledermix and calcium hydroxide pastes on the diffusion of corticosteroid and tetracycline through human tooth roots in vitro.

A 50:50 mixture of a corticosteroid/antibiotic paste and calcium hydroxide has been used clinically as a root canal dressing agent. This study investigated the effect on the release and diffusion of the corticosteroid and antibiotic components of Ledermix paste when it was mixed with a calcium hydroxide-methyl cellulose paste. The release rates of the trace molecules were lower when the mixture was used compared with release from Ledermix alone. The results indicated that this combination of materials, when used a long-term intracanal dressing, was likely to be more effective than Ledermix alone.

Calcium Hydroxide↗