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PubMed2005

Do procedural errors cause endodontic treatment failure?

BACKGROUND: This article reviews the effect of endodontic procedural errors, such as underfilling, overfilling, root perforations and separated instruments, on the outcome of endodontic therapy. TYPES OF STUDIES REVIEWED: Filling the root canal more than 2 millimeters from the radiographic apex (underfilling) or beyond the radiographic apex (overfilling), perforations of the root canal system and instrument separation are possible complications of endodontic therapy. Although these procedural errors may have different causes, they all may affect the outcome of treatment. RESULTS: Endodontic procedural errors are not the direct cause of treatment failure; rather, the presence of pathogens in the incompletely treated or untreated root canal system is the primary cause of periradicular pathosis. Procedural errors typically are due to several factors. Among them is a lack of understanding of the root canal anatomy, the principles of mechanical instrumentation and tissue wound healing. CLINICAL IMPLICATIONS: Procedural errors impede endodontic therapy, thus increasing the risk of treatment failure, especially in teeth with necrotic pulps and periradicular lesions. However, procedural errors often are preventable.

Bacterial Infections↗

PubMed2002

Endodontic therapy in a 3-rooted mandibular first molar: importance of a thorough radiographic examination.

This case report describes endodontic therapy on a mandibular first molar with unusual root morphology. In the initial treatment the working length had been determined with only an apex locator; no periapical radiographs had been obtained because the patient was pregnant. The root canal into an additional distolingual root had not been found and was therefore left untreated, which led to treatment failure after 11 months. The radiographic examination performed in a subsequent endodontic treatment allowed detection of the anomalous root and completion of the root canal treatment. The distolingual root canal would have been identified during the initial endodontic therapy if a thorough radiographic examination had been carried out. This report highlights the importance of radiographic examination and points out the need to look for additional canals and unusual canal morphology associated with a mandibular first molar. Radiographic examination during pregnancy is also discussed.

Adult↗

PubMed2006

An ex vivo evaluation of a new root canal irrigation technique with intracanal aspiration.

AIM: To evaluate the effectiveness of a new root canal irrigation technique with intracanal aspiration in removing the smear layer and to assess irrigant extrusion ex vivo. METHODOLOGY: Thirty-five instrumented canals of extracted human canine teeth that had been resected apically by removing 3 mm of the root tip were divided into one control and four experimental groups of seven teeth each. The roots were fixed in a plastic case and surrounded with normal saline agar coloured with 1% acid red. No irrigation was performed in the control teeth. Each root canal in the experimental groups was irrigated with 9 mL of 14% ethylenediaminetetraacetic acid for 3 min, and then with 6 mL of 6% sodium hypochlorite (NaOCl) for 2 min. In the intracanal aspiration technique, the irrigant was delivered from the tip of an injection needle placed 12 mm from the apical root-end and an aspiration needle that was connected to a Root ZX apex locator placed 2 and 3 mm short of the apical root-end in groups 1 and 2, respectively. In the conventional method, the tip of an injection needle used for delivery of the irrigant and as an active electrode was placed 2 and 3 mm short of the apical root-end in groups 3 and 4, respectively, the tip of the aspiration needle was placed 12 mm from the apical root-end in these groups. The readings of the Root ZX during irrigation were recorded. The cleanliness of the canal was evaluated by scoring smear layer from scanning electron microscopy (SEM) images of the canal. Extrusion of NaOCl was detected by measuring the discoloured area of the agar around the apical root-end. The data obtained were statistically analysed by one-way anova, the Kruskal-Wallis test and Friedman's test. RESULTS: In the SEM study, the canals in groups 1-3 were significantly cleaner than those in the control and group 4 (P < 0.05). The mean Root ZX readings in groups 1-3 were approximately "0.5". The discoloured area in group 3 was significantly larger than the other groups (P < 0.05). CONCLUSIONS: Irrigation using the intracanal aspiration technique allowed more effective removal of the smear layer than that performed by the conventional method in an apically resected canine tooth. The intracanal aspiration technique produced limited extrusion of the irrigant beyond the apical foramen.

Apicoectomy↗

PubMed1978

Prevalence, location, and patency of accessory canals in the furcation region of permanent molars.

One hundred and two extracted permanent molars were debrided in 3% H2O2, sealed at the apex, and placed in a vacuum chamber. Safranin dye was introduced into the teeth that were placed in a vacuum of 525 mm of Hg. Observations were made of the external root surface to determine any staining due to patent accessory canals. Accessory canals were demonstrated in the "furcation region" in 28.4% of the total sample; 29.4% in mandibular molars, and 27.4% in maxillary molars. Of the total sample 25.5% exhibited canals in the "furcation" only, while 10.2% exhibited canals on the lateral root surface. Communication between the pulp chamber and the external surface was noted via dentinal tubules, especially when the cementum was denuded. The salient biologic and pathologic ramification of these aberrant canals were discussed along with the need to establish a differential diagnosis in order to determine the proper sequence of treatment should pulpal-periodontal disease exist.

Dental Pulp Cavity↗

PubMed2004

Is the lingual forming part of the incisor a structural entity? Evidences from the fragilitas ossium (fro/fro) mouse mutation and the TGFbeta1 overexpressing transgenic strain.

Our objective was to study the teeth of a mutant mice fro/fro that display severe forms of osteogenesis imperfecta. One day and 8 week-old fro/fro and +/fro heterozygote mice (wild type, WT) were processed for light and scanning electron microscopy. The genetic defect, shown to be located on chromosome 8, induced alveolar bone and teeth hypomineralisation. Due to defective cell proliferation in the fro/fro, the distal growth of the mandibular incisors was impaired. Immunolabelling revealed an increase of chondroitin/dermatan sulphate, whereas no difference was detected in dental tissues for decorin and biglycan. Amelogenin expression was decreased in the incisor and enhanced in the molar. Dentin sialoprotein was below the level of detection in the fro/fro, whereas osteonectin and osteopontin were unchanged. The main target of the mutation was seen in the lingual part of the incisor near the apex where dentine formation was delayed. In the molars, bulbous roots with obliteration of the pulp chamber were seen. In the TGFbeta1 overexpressing mice, the lingual root-analogue part of the incisor was missing. In the molar, short roots, circumpulpal dentine of the osteodentine type and pulp obliteration were seen. It may be noted that, although the mutant and transgenic strains mutations are two different genetic alterations not related to the same defective gene, in both cases the expression of the dentin sialoprotein is altered. Altogether, the present data suggest that the lingual forming part of the incisor seems to be an anatomical entity bearing its own biological specificities.

Amelogenin↗

PubMed2005

Biometric study of furcation area of first maxillary molars.

The present investigation was designed to study the distance from the 3 bifurcation entrances to their opposite roots, and also the virtual center of the trifurcation (TC), which is equidistant from each bifurcation entrance, of maxillary molars. Thirty-five teeth devoid of any surface damage or fused roots were selected. Roots were included in acrylic resin and cross-sectioned at the cementoenamel junction to the apex using a rotary diamond blade and 0.45-mm slices were obtained. A profile projector apparatus was used to obtain the coordinated points on a Cartesian plane, which allowed the calculation of all distances present using analytic geometric formulas. Based on statistical analysis (comparison by Kruskal-Wallis ANOVA test, p<0.05), the following results were obtained: 1) mean distance from the buccal furcation reaching the palatal root was 6.72 +/- 0.99 mm (range 4.73-8.67 mm); 2) mean distance from the mesial and distal furcations to the distal and mesial roots were 5.42 +/- 0.83 mm (range 3.78-7.07 mm) and 5.90 +/- 0.87 mm (range 4.18-7.59 mm), respectively. All means were determined up to the point of 1.40 mm from each bifurcation opening; 3) mean distance of TC was 4.26 +/- 0.42 mm (range 3.44-5.08 mm) for all levels.

Analysis of Variance↗

PubMed1990

[Histopathological studies on tissue reactions to experimental root canal sealer in cats].

This study was designed to elucidate whether or not the root canal sealers, newly prepared here, show high affinities and promote the osteo-cicatric healing for the remaining dental pulp and periapical regions. For these purposes, I used two types of sealers, newly devised here and mainly composed of powdered corals mixed with propyreneglycol for the experiment 1 and powdered human dentins mixed with atelocollagen implant for the experiment 2. Guttapercha points with these sealers were applied in the premolar and molar tooth mesial or distal canals of 24 adult cats, whereas in controls guttapercha points with Canals, made commercially, were used instead of these sealers. After treatment, the periapical tissues and accessory root canal regions were histopathologically observed at different intervals throughout 30 to 130 days. The results obtained were as follows: 1. When guttapercha points were penetrated beyond the apical foramen and reached periapical tissues, prolonged inflammatory reactions of a slight or medium degree were observed in all three types of sealers. 2. When Canals were applied, prolonged inflammatory reactions were persistent if the sealer flooded out. In contrast, if they were in just-filling (Type-I, as termed in text), inflammatory reactions were often detectable at the accessory root regions. Many exudative inflammatory cells around the over-tip of guttapercha points were seen, as compared around the apicals of the dental root. 3. When powdered coral was used, strong inflammatory reactions was little found. Adjunction of the new bone was usually observed in the alveolar bone. The tendency of scar formations was seen in the periapical tissues where the inflammatory reaction was assumed to have occurred. 4. When powdered human dentin was used, in any experiments, inflammatory reaction were not seen with a few exceptions. However, if inflammatory responses were existed in a few cases, their degrees were relatively strong. 5. If the debris of dentin was blocked within the root canal apex, fine examples were seen regardless of the three types of the sealers. 6. Calcium in the powdered coral showed a conspicuous peak by energy X-ray analysis. The ratio of Ca and P of powdered human dentin was 1:1. From the above findings, both powdered coral and powdered human dentin could be useful as composites of sealers.

Animals↗

PubMed1996

[The role of the traditional radiological methods in conservative therapy and endodontics].

The traditional radiographic examinations used in restorative dentistry and endodontics are: intraoral radiograph performed in the beta-wing or the paralleling technique, the partial extraoral radiograph (rotational narrow beam), the panoramic radiography and the periapical radiographs with the bisecting technique which is particularly suitable for visualization of the apex. Radiology is a valuable diagnostic means to evaluate the extension of primary caries, to identify secondary and interproximal initial decays and if required let the therapist measure the biological width. Several factors influence the radiographic interpretation of caries: cervical burnout, mach band effect, internal and external resorption, restorative materials for fillings and sub-bases, abrasions and/or erosions. Radiology allows the diagnosis of developmental and acquired abnormalities of the teeth which can have an influence on the treatment itself. Examples are: variations in the shape of the crown and root, dens in dente, enamel hypoplasia, dentinogenesis imperfecta. Radiograms are of major importance in the evaluation of restorative dentistry results: precision of the margins, congruous contact points, fractures. Moreover, it provides the endodontic procedures with useful diagnostic data and permits the measurements during the treatment, supplying the immediate and long term checks too.

Dental Caries↗

PubMed2003

Osseotite vs. machined surface in poor bone quality. A study in dogs.

Implant sites with low bone content have exhibited lower implant survival rates than dense bone areas. Alterations of the implant surface seem to influence the bone-to-implant contact rate and may have an impact on implant failure rates in such sites. It was the objective of this animal study to histomorphometrically compare two different implant surfaces in so-called poor bone quality sites. All premolars on one side of the mandible were extracted in five fox hounds. After a healing time of 8 months, four screw-type implants (two with a machined surface (ICE group) and two with a double acid-etched (Osseotite) surface (OSS group)) were inserted into the mandible. Upon insertion, the implant apex was located in the 'hollow' part of the dog mandible, where the bone content is low. After 4 months healing, histomorphometric evaluations were performed. All implants osseointegrated clinically and histologically. Periapical density measurements revealed similar bone contents in both groups (ICE 49.9+/-16.7%, OSS 52.2+/-8.4%; P>0.05). Despite these similar amounts of bone content in the apical area around the implant, the Osseotite implant surface had a significantly higher bone-to-implant contact rate than the machined surface (OSS 62.9+/-12.4%, ICE 39.5+/-13.0%; P<0.01). It is concluded from this animal experiment that, in poor bone quality sites, an implant with an Osseotite surface can achieve a significantly higher bone-to-implant contact compared to a machined surface.

Animals↗

PubMed1996

An in vivo comparison of gradient and absolute impedance electronic apex locators.

Two electronic apex locators based on the gradient (Apit) and absolute (Odontometer) impedance principles were evaluated. Distances of file tips to apical foramina were determined in vivo with the electronic apex locators and subsequently verified after extraction. Mean differences between file tips and apical foramina were +0.14 +/- 0.27 mm and -0.36 +/- 0.71 mm for the Apit and Odontometer, respectively. These differences were statistically significant (p < 0.001). the Apit's and Odontometer's results ranged from +0.85 to -0.65 mm and from +0.35 to 2.45 mm from the apical foramen, respectively. Ninety-three and 73% of the findings for the Apit and the Odontometer, respectively, were within the +/- 0.5 mm range, whereas 100% and 86%, respectively, were within the +/- 1.0 mm range. Thirty-three and 43% of the results for the Apit and the Odontometer, respectively, were 1.0 mm or less coronal to the apical foramen. The Apit tended to yield the more reliable results because of the narrower range.

Adult↗

PubMed1991

Immunocytochemical localization of laminin in the epithelial rests of Malassez of immature rat molars.

Immediately after disruption of Hertwig's root sheath, epithelial cells were found near the root apex, singly or in groups of two or three cells. They were irregular in shape with only a partial lining of basal lamina. Immunoreactivity for laminin was intense in the basal lamina and weak between projections of the epithelial cells. In 5-week-old rats, the epithelial rests consisted of about five cells and still had an incomplete basal lamina with collagen fibrils in the intercellular spaces. Immunoreaction products were seen in the basal lamina and diffusely in the intercellular spaces. The epithelial rests of 9-week-old rats had more cells, an almost complete lining of basal lamina, and narrowed intercellular spaces. Immunoreaction products were seen in the basal lamina but not in the intercellular spaces. These findings indicate the basal lamina is involved in the formation of the epithelial rests.

Animals↗

PubMed2002

Initial stress produced in the periodontal membrane by orthodontic loads in the presence of varying loss of alveolar bone: a three-dimensional finite element analysis.

The aim of this study was to investigate the stress components (S1 and S3) that appear in the periodontal membrane (PDM), when subjected to transverse and vertical loads equal to 1 N. A further aim was to quantify the alteration in stress that occurs as alveolar bone is reduced in height by 1, 2.5, 5, 6.5, and 8 mm, respectively. Six three-dimensional (3D) finite element models (FEM) of a human maxillary central incisor were designed. The models were of the same configuration except for the alveolar bone height. Special attention was paid to changes of the stress components produced at the cervical, apical, and sub-apical levels. In the absence of alveolar bone loss, a tipping force of 1 N produced stresses, which reached 0.072 N/mm2 at the cervical margin, up to 0.0395 N/mm2 at the apex and up to 0.026 N/mm2 sub-apically. In the presence of 8 mm of alveolar bone loss, the findings were -0.288, 0.472, and 0.722 N/mm2, respectively. Without bone loss, an intruding force of the same magnitude produced stresses of -0.0043, -0.0263, and 0.115 N/mm2, respectively, for the same areas and sampling points. In the presence of 8 mm of alveolar bone loss the findings were -0.019, -0.043, and 0.185 N/mm2 for intrusive movement. The results showed that alveolar bone loss caused increased stress production under the same load compared with healthy bone support (without alveolar bone resorption). Tipping movements resulted in an increased level of stress at the cervical margin of the PDM in all sampling points and at all stages of alveolar bone loss. These increased stress components were found to be at the sub-apical and apical levels for intrusive movement.

Alveolar Bone Loss↗

PubMed1995

In vitro evaluation of the accuracy of several electronic apex locators.

This study describes two tests of the in vitro accuracy of several models of electronic canal length measuring devices (ECLMDs) using a gelatin test model and extracted human teeth with fully formed apices. In part 1, four previously untested ECLMDs were used in dry canals after access and pulpectomy. File lengths with wth file tip just visible at the foramen were compared to ECLMD lengths. Clinically significant ECLMD measurements of > or + 0.5 mm than visual length were noted with two ECLMDs 16.6% and 10% of the time. The other two ECLMDs had no measurements >0.5 mm than the visual measurement. The gelatin test model proved highly accurate with 4 of 6 ECLMDs tested thus far. Part 2 compared the accuracy of a previously tested ECLMD using the gelatin model when taking length measurements with canals both dry and wet with distilled water in them. There was no difference between measurements in wet or dry canals. Irrigation with distilled water may be a clinical aid when using resistance ECLMDs.

Cuspid↗

PubMed2006

Test of the Lamendin aging method on two historic skeletal samples.

The Lamendin aging method involves the quantification of root translucency and the attachment position of the periodontal membrane. It was developed using recent medical-examiner specimens, and was tested on modern skeletal samples such as the Terry Collection (Lamendin et al. [1992] J. Forensic Sci. 37:1373-1379; Prince and Ubelaker [2002] J. Forensic Sci. 47:107-116). The method may be one of the most useful for estimating age after the mid-30s. The current study is an evaluation of the Lamendin criteria on two historic skeletal samples from Britain. Both the Christ's Church Spitalfields and St. Bride's Church collections represent documented skeletal samples that were interred in the 18th and 19th centuries. In total, 1,188 teeth from 220 adult individuals were examined from these two collections. The Lamendin method requires measuring total root length (cementoenamel junction to apex), gingival regression (cementoenamel junction to periodontal ligament attachment), and root translucency (root apex to maximum level of root translucency) on the labial surface of single-rooted teeth. Our results indicate that postmortem factors affect the applicability of the Lamendin technique to archaeological and historical samples. In particular, root translucency disappears with time, or is obscured by unknown postmortem taphonomic effects related to the length of interment or postmortem environment. Thirty-five percent of our sample showed no root translucency, indicating that caution is required when applying this method to archaeological or historical remains. The mean error of age estimates for Spitalfields and St. Bride's was higher than in the original study of Lamendin et al. ([1992] J. Forensic Sci. 37: 1373-1379), and higher than in the test by Prince and Ubelaker ([2002] J. Forensic Sci. 47:107-116) of the Lamendin method on the Terry Collection.

Adult↗

PubMed1995

Radiovisiography versus conventional radiography for detection of small instruments in endodontic length determination. Part 1. In vitro evaluation.

Radiovisiography is a new intraoral radiographic imaging system. In this in vitro investigation, radiovisiography was compared with conventional radiographs viewed with x2 magnification. Twenty-five extracted maxillary molars were evaluated for clarity of size 8 and 10 endodontic file tips in relation to the radiographic apex. Five images of radiovisiography were compared with D-speed and E-speed radiographs: original, enhanced, negative-to-positive, standard zoom, and zoom in the negative-to-positive mode. D-speed radiographs were also compared with E-speed radiographs. Zoom in the negative-to-positive mode was statistically equivalent to D-speed radiographs (p = 0.264) and superior to E-speed radiographs (p < 0.001). The standard zoom was also superior to E-speed radiographs (p = 0.025). D-speed radiographs were statistically superior to E-speed radiographs; being judged better than E-speed 90% of the time. Accurate identification of the position of the tips of size 8 and 10 files was achieved on all D- and E-speed radiographs with the use of magnification.

Dental Pulp Cavity↗

PubMed1976

Intentional retention of vital submerged roots in dogs.

In this study, intact and untreated roots of twelve teeth in three dogs were submerged 2 mm. below the alveolar bone crest. On eight regeneration of alveolar bone was seen in 3 weeks, with complete bone coverage in 5 weeks. A complete lamina dura surrounded the buried roots, the original root canal tissue remained vital, and vessels and other structures now entered (or exited) from both ends. Cementum covered the cut end, making the end similar to a normal apex. Bone failed to regenerate completely over four of the twelve roots. Two of these had dentinal spicules which impeded complete bone coverage (Fig 9). Another was a case of delayed healing due to the early loss of sutures and subsequent infection where a sinus tract developed, connecting the oral environment with the resected root. This led to bone resorption and a partial pulp necrosis. In the fourth case the decreased depth of root burial and subsequent lack of bone cover led to external resorption of the cut dentin. Histologic examination after 12 weeks revealed the regeneration of bone, a regenerated periodontal membrane, and a layer of cementoblasts over the cut and exposed root dentin in a typical manner. This study suggests that when healthy bone and roots are present, particularly in an otherwise edentulous mandible retaining only a few nonrestorable anterior teeth, the roots can be retained in a nonpathologic state by means of a simple surgical technique.

Alveolar Process↗

PubMed1995

Radiovisiography versus conventional radiography for detection of small instruments in endodontic length determination. II. In vivo evaluation.

Radiovisiography was compared clinically to conventional D-speed and E-speed radiographs viewed with X 2 magnification using the mesiobuccal root of maxillary molars of 22 patients. Clarity of size 8 and 10 endodontic file tips in relation to the radiographic apex was the object of comparison. Five images of radovisiography, (original, enhanced, negative-to-positive mode), were compared to D-speed and E-speed radiographs. D-speed radiographs were also compared to E-speed radiographs. D-speed radiographs were statistically superior to all five radiovisiography images. Four of the radiovisiography images were equivalent to E-speed radiographs. D-speed radiographs provided superior recognition of small file tips when compared to E-speed radiographs 100% of the time. Accurate identification of the small file tips was achieved on 95% of D-speed and 70% of E-speed radiographs. With radiovisiography, identification was achieved on 95% of the zoom images in the negative-to-positive mode, 86% of enhanced, 82% of standard zoom, and 77% of the images in negative-to-positive conversion.

Adult↗

PubMed1992

The apical seal of root canal sealing cements using a radionuclide detection technique.

The aim of this study was to evaluate the apical seal obtained with various root canal sealing cements using a new method based on the use of a radionuclide and an external detection technique. A total of 150 maxillary incisors and canines, which had been kept in saline solution, were used. The root canals were instrumented with a stepback technique and circumferential filing. Six experimental groups and two control groups were randomly formed. Each experimental group was obturated by a lateral condensation technique with gutta-percha points and a different sealing cement (two based on zinc oxide-eugenol cement, two based on resins and two on calcium hydroxide); the positive control used gutta-percha without sealing cement, while in the negative control the apex was covered with nail varnish, leaving the root canal empty. The apical leakage was measured using an external detection technique after submerging the root apices in a solution containing the radioisotope metastable 99Tc. No leakage was observed in the negative control group. There was a large difference between the leakage observed in the positive control group and the experimental groups. The best seal was obtained using Sealapex cement, which differed significantly from AH26, Tubli-Seal and Diaket; there was no significant difference between the latter. The poorest results were obtained with Endomethasone and CRCS; there was a significant difference between these and the previous three sealing cements.

Administration, Topical↗