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A new mineral trioxide aggregate root-end filling technique.

Carrier and syringe-type devices are currently used to deliver mineral trioxide aggregate as a root-end filling material. In certain surgical situations these devices may be too difficult to use because of the location of the surgical site and the small size of the root-end preparation. This paper describes a new technique to overcome these difficulties by the formation and delivery of mineral trioxide aggregate pellets.

Aluminum Compounds↗

Effect of an acid environment on leakage of root-end filling materials.

One hundred fifty-six single-rooted human extracted teeth received root canal treatment, apicoectomy, and ultrasonic root-end preparations. The roots were divided into six groups of 24 teeth. The groups were filled with Amalgam, Geristore, Super-EBA, Mineral Trioxide Aggregate (MTA), Calcium Phosphate Cement (CPC), or MTA with CPC matrix, respectively. Immediately after root-end filling, 12 teeth from each group were exposed to a pH of 5.0 for 24 h, and 12 teeth were exposed to a pH of 7.4 for 24 h. Twelve teeth served as controls. All teeth were exposed to Pelikan Ink for 5 days and cleared. Linear dye leakage was recorded. Data were statistically analyzed. An acid pH significantly reduced dye leakage of Geristore (0.67 vs. 3.93 mm) and MTA with CPC matrix (0.54 vs. 2.41 mm), whereas leakage of all other materials was not affected by pH. In conclusion an acid environment did not hinder the sealing ability of any of the materials tested, and enhanced the sealing ability of Geristore and MTA with CPC matrix.

Acids↗

A comparative evaluation of three root-end filling materials: an in vitro leakage study using Prevotella nigrescens.

This study used Prevotella nigrescens to evaluate the sealing ability of Geristore, Super-EBA, and ProRoot when used as root-end filling materials. One hundred single-canal, extracted, human teeth were cleaned and shaped with Gates-Glidden burs and .04 Taper (ProFile Series 29) rotary instruments. The root-ends were resected, and a 3-mm deep root-end preparation was made with ultrasonic tips. After steam sterilization, the teeth were randomly divided into three groups of 30. Each group was root-end-filled with a different material. Five root-end cavities were left open and served as positive controls; another five root-end cavities filled with sticky wax and covered with two layers of nail polish acted as negative controls. The teeth were attached to presterilized snap-on plastic caps; the root-ends submerged into 12-ml vials of chopped meat carbohydrate broth and placed in an anaerobic chamber. Twice a week, a sterile micropipette was used to inoculate 0.1 ml of a broth culture of Prevotella nigrescens into the root canal of each tooth. Results after 47 days indicated there were no significant differences between the three root-end filling materials against penetration of Prevotella nigrescens.

Aluminum Compounds↗

Microleakage of root-end filling materials.

The purpose of this study was to evaluate the microleakage of various root-end filling materials using a fluid filtration system. Sixty extracted human single-rooted teeth were used. The crowns were removed, the canals prepared, and root-end fillings placed. The samples were divided into two control and five experimental groups. The root-end filling materials tested were: amalgam, Intermediate Restorative Material (IRM), a dentin-bonded resin, Super-EBA, and mineral trioxide aggregate. The results showed that amalgam root-end fillings demonstrated significantly more microleakage than Super-EBA, dentin-bonded resin, or mineral trioxide aggregate. There was no significant difference between amalgam and IRM. However IRM was also not significantly different from the other three groups. There were no significant differences between the other three groups.

Aluminum Compounds↗

The continuous locking suture technique.

The continuous locking suture technique is described for use in endodontic surgery. The technique is an effective way to close Ochsenbein-Luebke flaps. The importance of the assistant's role is described. The technique's advantages and disadvantages are discussed.

Dental Assistants↗

Ability of three root-end filling materials to prevent bacterial leakage.

This study evaluated the ability of three materials--a resinous root canal sealer (Sealer 26) prepared in a thick consistence, a reinforced zinc oxide-eugenol cement (IRM), and a glass-ionomer cement (Fuji IX)--in preventing bacterial leakage. Retrofilled teeth were mounted in an apparatus and then challenged by human saliva. The number of days required for the bacteria from saliva to penetrate the root-end filling materials was determined. Evaluation was conducted for 60 days. Leakage was observed in all teeth of the Fuji IX group, and in 95% (19 of 20 specimens) of the teeth retrofilled with IRM. Sixty-five percent (13 of 20 teeth) of the teeth retrofilled with Sealer 26 showed leakage. No difference was detected between Fuji IX and IRM (p > 0.05). However Sealer 26 was significantly more effective in preventing bacterial leakage when compared with other materials tested (p < 0.05).

Bacteria↗

Leakage evaluation of root end filling materials using endotoxin.

Mineral trioxide aggregate (MTA) has been shown to possess excellent sealing ability when tested with dye, bacteria, and a fluid filtration technique. Endotoxin, a component of the cell wall of Gram-negative bacteria, has been proposed to play a role in the pathogenesis of periradicular lesions. This study used a modified Limulus Amebocyte Lysate test for the presence of endotoxin as a tracer and compared the sealing ability of Super-EBA, IRM, amalgam, and MTA. The results showed that MTA permitted less endotoxin leakage than IRM and amalgam at 1, 2, 6, and 12 wk (p < 0.05), and leaked less than Super-EBA at 2 and 12 wk (p < 0.05).

Aluminum Compounds↗

Finishing of glass ionomer retroseals.

Various techniques have been suggested for the finishing of retrosealing materials. By measuring marginal leakage and by the use of scanning electronic microscopy, this study evaluated the use of bone files, burnishers, and Shofu points for the finishing of 60 retrosealings done with glass ionomer. With each of the three finishing agents, one group of teeth was polished with movements directed from the palatal toward the buccal, and in another group it was done from the center of the retroseal toward the margins of the cavity. ANOVA showed significant differences among the groups according to the way the finishing was done. The use of instruments from the center to the margins of the cavity rather than in just one direction always caused less leakage. The Shofu stone and the burnisher caused equivalent leakage which was significantly less than that caused by bone files. Scanning electron microscopic photos show that the use of the instrument in only one direction caused the material to shift away from the palatal side. This shift always led to greater leakage of dyes on that side.

Analysis of Variance↗

Hemostatic efficacy and cardiovascular effects of agents used during endodontic surgery.

The hemostatic efficacy, as well as the cardiovascular effects, of two hemostatic agents currently used during endodontic surgery was examined. The hemostatic agents used were epinephrine pellets (Racellet pellets) or 20% ferric sulfate (Viscostat). Patients were assigned to one of two experimental groups. Blood pressure and pulse rate were recorded pre- and postoperatively and at three additional times during the surgery (root-end resection, root-end preparation, and filling). The adequacy of hemostasis was rated by the surgical operator. Results indicated that there is no significant change in cardiovascular effects when using either of these hemostatic agents. Except in one case where ferric sulfate was the agent, both agents produced surgical hemostasis that allowed for a dry field for root-end filling.

Administration, Topical↗

Long-term follow-up of cases considered healed one year after apical microsurgery.

A previous report demonstrated 96.8% healing within 1 yr after apical surgery was performed with the surgical operating microscope and Super-EBA as the root-end filling material. The purpose of this paper is to report on the long-term follow-up of those cases that were considered healed at the short term. Clinical examinations were made and radiographs were evaluated 5 to 7 yr after the case had first been considered healed. Criteria for determining healed cases were the same as those used in the first report. Of the 59 roots evaluated, 54 (91.5%) remained healed, whereas 5 (8.5%) showed evidence of apical deterioration.

Dental Pulp Diseases↗

Reflections on designing and conducting long-term surgical studies.

Endodontic literature is replete with surgical success-failure studies. Efforts to compare them should be avoided because there are so many variables within each of these studies. Among these variables can be surgical technique, clinical ability, restorative materials, the use of pooled data, and interpretation of data. Many of these studies serve as an historical reference from which current-day evaluators can build and design studies that are more contemporary and relevant to modern endodontic surgery. If a study is to be considered valid, it should strive to examine a well-controlled population and use a reproducible and rigorous surgical protocol. It is often difficult for the reader to know how much credibility to place on a given study until he or she understands the criteria for the various types of success-failure studies.

Dental Research↗

The effect of irrigation with doxycycline or citric acid on leakage and osseous wound healing.

This study investigated the effect of doxycycline irrigation on wound healing and the apical seal of three filling materials. Part 1: 220 extracted teeth received root canal therapy followed by root resection (2 mm) and ultrasonic root end preparations (3 mm). Groups of 20 were irrigated with saline, citric acid, or doxycycline and filled with amalgam, Super EBA, or MTA. Leakage was measured (mm) after decalcification and clearing. Part 2: two defects were made on each side of the mandible of 10 New Zealand rabbits. On each side, one defect was irrigated with saline and one with either citric acid or doxycycline. The animals were killed in groups of five at 9 and 18 days. Sections of each defect were stained with hematoxylin and eosin for evaluation of healing and bone fill. Super EBA and MTA leaked significantly less than amalgam, regardless of irrigant. Leakage after irrigation with doxycycline compared to citric acid or saline was not significantly different for Super EBA or MTA but was lower for amalgam. There was no significant difference in healing or bone fill among irrigants at 9 or 18 days.

Aluminum Compounds↗

Retrograde treatment in an extensive implant-tooth-supported reconstruction.

Diagnosis and treatment of chronic apical periodontitis associated with an abutment tooth in an extensive tooth-implant-supported fixed prosthesis is reported. Careful, complete interpretation of clinical data was imperative because the periapical radiolucency presented around the apex of a vital tooth. A retrograde endodontic approach was used to prevent an adverse outcome to the complex rehabilitative treatment that had been performed over many years.

Adult↗

Antibacterial effects of resinous retrograde root filling materials.

The effect of three resinous retrograde root filling materials on the growth of four obligate anaerobic bacteria associated with endodontic infections was determined by using the agar diffusion inhibitory test. Samples of the following resinous materials (resin-modified, glass-ionomer cement, Fuji II LC; compomer, Dyract; and composite resin, Spectrum) were incubated for 1 week with the following anaerobic bacteria: Fusobacterium nucleatum, Porphyromonas gingivalis, P. endodontalis, and Prevotella intermedia. The freshly mixed and set resinous materials were placed into the prepared wells of agar plates inoculated with the test microorganisms for 1 week. After the end of the incubation period, the zone of growth inhibition was observed and measured. Analysis of variance of the mean diameter of the zone of inhibition indicated no statistically significant overall differences in the response of the black-pigmented Bacteroides species (p > 0.05). For F. nucleatum, Spectrum had more antibacterial effect against this bacteria than Dyract (p < 0.05). Additionally, Fuji II LC was ineffective against F. nucleatum (p < 0.05). However, positive control plates showed bacterial growth in all cases. Our data suggest that the antibacterial potency of polymerized materials varied considerably, depending on the type and the product tested.

Analysis of Variance↗

The comparative sealing ability of hydroxyapatite cement, mineral trioxide aggregate, and super ethoxybenzoic acid as root-end filling materials.

A comparison was made of the ability of hydroxyapatite cement, mineral trioxide aggregate, and super ethoxybenzoic acid to prevent the leakage of bacteria from root canals, when used as root-end filling materials. The materials were tested in a double-chamber device in which a root segment connects the upper (delivery) chamber and the lower (receiving) chamber. The root segment was prepared by having the root canal instrumented to a #45 file, and a 3-mm-deep, root-end preparation placed at the apical foramen. The canal of each root segment was filled with gutta-percha, and the root-end preparation was filled with one of three test materials, mixed according to the manufacturer's directions. Negative controls were constructed with sticky wax sealing the apical foramen. A titered suspension of radioactively (3H-thymidine)-labeled bacteria (Enterococcus fecalis) was placed into the delivery chamber, and sterile saline was placed into the receiving chamber such that the apical third of each root section was immersed. At various time points, samples were taken from the receiving chamber, and measured for 3H activity. The results indicated that (a) all the test materials leaked significantly compared with the negative controls; and (b) there was no significant difference found between the leakage rates of the three materials tested.

Aluminum Compounds↗

The effect of calcium sulfate on hard-tissue healing after periradicular surgery.

The purpose of this study was to determine the effect of calcium sulfate (CS) on cementum deposition and osseous healing after periradicular surgery. The root canals of 24 mandibular premolars in four 2-yr-old beagle dogs were endodontically treated, followed 2 weeks later by periradicular surgery. Mineral trioxide aggregate (MTA) was used as root-end-filling material. The right or left side was assigned at random to receive CS alpha-hemihydrate or no material in the osteotomy sites before closure. The animals were killed after 4 months. Hard-tissue healing was analyzed histomorphometrically. All samples displayed evidence of cementum deposition adjacent to the root-end fillings and bone regeneration in the osteotomy sites. The data was analyzed using the Mann-Whitney U test, comparing the scores for cementum and osseous healing of the two groups at significance level of alpha = 0.05. The results indicated that placement of CS in osteotomy sites after periradicular surgery does not significantly affect periradicular healing.

Aluminum Compounds↗

Hard-tissue healing after application of fresh or set MTA as root-end-filling material.

The purpose of this study was to compare the effect of fresh mineral trioxide aggregate (MTA) with set MTA on hard-tissue healing after periradicular surgery. The root canals of 24 mandibular premolars in four 2-yr-old beagle dogs were filled with MTA. Two weeks later the root ends of half of the samples were surgically exposed and resected to the set MTA within the canals. After exposing and resecting the other 12 root ends, they were prepared with ultrasonic instrumentation and preparations were filled with fresh MTA. After 4 months, the animals were killed. Hard-tissue healing was analyzed histomorphometrically. The results indicated that although freshly placed MTA resulted in a significantly higher incidence of cementum formation (12 of 12 versus 8 of 12, p = 0.028), there is no significant difference in the quantity of cementum or osseous healing associated with freshly placed or set MTA when used as root-end-filling material.

Aluminum Compounds↗

Comparative study of sealing ability of two root-end-filling materials with and without the use of dentin-bonding agents.

The purpose of this study was to examine microleakage of two root-end-filling materials with and without the use of bonding agents. For microleakage measurement a fluid transport model was used. Sixty single-rooted teeth were used in this study. They were prepared with step-back technique and then an apicoectomy was performed. Then the teeth were divided into four groups. Group A were filled with Fuji II LC glass-ionomer cement, group B were filled with Fuji II LC and a new bonding agent, Fuji Bond, group C were filled with Admira composite resin, and group D were filled with Admira and Admira Bond, a new bonding agent. At 24 h, 1 month, and 2 months after filling the leakage along these filling materials was determined under a low pressure of 0.1 atm. At all experimental times, glass-ionomer groups showed significantly less microleakage than resins groups. Between Admira and Admira Bond groups, significantly less leakage was observed in the root sections with Admira Bond at 24 h.

Apicoectomy↗