PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Tooth Apex”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 163 records · Page 9Linked to original sources
PubMed2004

Anatomy of the pulp-chamber floor.

Locating the number and position of orifices on pulp-chamber floors can be difficult. This is especially true when the tooth being treated is heavily restored, malposed, or calcified. After evaluating 500 pulp chambers of extracted teeth, new laws for finding pulp chambers and root-canal orifices are proposed. The use of these laws can aid in the determination of the pulp-chamber position and the exact location and number of root canals in any individual tooth.

Color↗
PubMed2004

Evaluation of the influence of smear layer on the apical and coronal sealing ability of two sealers.

The aim of this in vitro study was to determine the effect of the smear layer on apical and coronal leakage in root canals obturated with AH26 or RoekoSeal sealers. A total of 160 maxillary anterior teeth extracted for periodontal reasons were used. The root canals were prepared to a size #7 with ProFile.06 taper Series 29 rotary instruments in a crown-down manner. Eight groups were created by all possible combinations of three factors: smear layer (present/absent), leakage assessment (apical/coronal), and sealer used (AH26/RoekoSeal). All teeth were obturated using lateral condensation technique of gutta-percha. A fluid filtration method was used to test apical or coronal leakage. According to the results of this study, the smear (+) groups displayed higher apical and coronal leakage than those smear (-) groups for both root canal sealers (p < 0.05). There was no statistically significant difference in either apical or coronal leakage between RoekoSeal and AH26, regardless of the presence or absence of the smear layer (p > 0.05). However, apical leakage was significantly higher than coronal leakage for both root canal sealers used in this study (p < 0.05). Under the conditions of this study, the results indicate that removal of the smear layer has a positive effect in reducing apical and coronal leakage for both AH26 and RoekoSeal root canal sealers.

Bismuth↗
PubMed2004

MTA obturation of pulpless teeth with open apices: bacterial leakage as detected by polymerase chain reaction assay.

Polymerase chain reaction (PCR) followed by reverse dot blot was used to detect Enterococcus faecalis leakage through mineral trioxide aggregate (MTA) apical obturations of pulpless teeth with open apices. Prepared root canals of 34 extracted teeth were given a standard apical foramen opening and received orthograde apical obturation with MTA; three groups had 1-, 2-, or 3-mm thickness. Sterilized specimens were inoculated with E. faecalis and incubated in sterile medium. DNA extracted from the specimens was amplified by polymerase chain reaction, which yielded a specific segment of E. faecalis 16S rDNA. On day 10 of incubation, no specimens were contaminated. On day 50, almost 17% of specimens were contaminated, with no statistically significant difference between groups (Chi-square = 0.48; df = 2; p = 0.787). Therefore, MTA provides an adequate seal even in cases of orthograde apical obturation of pulpless teeth with open apices.

Aluminum Compounds↗
PubMed2005

Root canal treatment in a mandibular second premolar with three root canals.

According to the endodontic literature, the possibility of three canals in mandibular second premolars is quite small. When three or more canals are present separation of the root canals has only been described at mid-root level. The present case describes root canal treatment of a root canal aberration at the level of the apical third (apical root canal separation starting at a length of 20 mm) where a combined use of the fiberoptic endoscope and the operating microscope was necessary to locate the canal orifices and to enter these orifices. The present report emphasizes the need of color contrast to enhance visualization.

Adult↗
PubMed2005

The role of apical instrumentation in root canal treatment: a review of the literature.

The issue of final apical preparation size remains controversial despite considerable clinical and in vitro research. The astute clinician must be aware of this research before choosing any instrumentation system because the informed clinician's decision must be guided by the best available evidenced-based information. This review article generated a Medline-based search strategy to disclose these studies and provides a critique and summary of the results.

Dental Instruments↗
PubMed2005

A comparative study of three different root canal curvature measurement techniques and measuring the canal access angle in curved canals.

In the first part of this study the Schneider (S), Weine (W), and Long-Axis (LA) techniques are used for comparing the measurement of canal curvature. One hundred mandibular first and second molar teeth were selected. Radiographs were taken after inserting size 10 K-files into the mesiobuccal root canals. The radiographic findings were digitized on a computer, and the three different curvature angles were measured from drawings of the same root canal and compared statistically. ANOVA showed that there were significant differences between the curvature angle values determined using each technique (p < 0.001). In the second part of this study the term "canal access angle" (CAA) was introduced and it was defined by examining the morphology of canal curvature. Canal length, curvature distance (y), curvature height (x), Schneider angle, and the newly defined CAA were evaluated statistically. Using a multiple regression analysis, the CAA was significantly related to x (p < 0.001) and y (p < 0.005). There was a positive correlation (r = 0.74) between the CAA and curvature height (x). The results indicated that the CAA is a more effective way of evaluating the root canal curvature.

Dental Pulp Cavity↗
PubMed1996

Intra-canal cutting ability of MM1500 files.

The aims of this study were to develop a model system capable of monitoring lateral forces during root canal preparation and to measure the cutting ability of files activated by the MM1500 sonic handpiece. Forces were monitored by a calibrated model system which utilized a combination of spring steel beams fitted with strain gauges, these were interfaced through two strain gauge amplifiers to an x-y recorder. Single rooted canine teeth (n = 36; 32 experimental, four control) were mounted in a two-part acrylic mould (which was an integral part of the model system) prior to sectioning horizontally 11 mm from the tooth apex. A 2(4) full factorial experiment with two replications was performed. Four variables were selected for evaluation, load (50 and 100 g), power (air inlet ring half or fully open), file type (Heliosonic or Shaper) and stroke rate (1 or 2 cycles per second). A new file (size 25) was used for 1 min in each canal with water irrigation. The control group was not instrumented. The cross-sectional root canal area was measured before and after instrumentation using image analysis and increase in area was used as an indication of cutting ability. The results showed that the increase in load, power and the Shaper file all produced a significant increase in cutting ability (ANOVA, P < 0.001). However, stroke rate was not found to have a significant effect (P > 0.05). None of the interactions between the variables were significant and there was no significant difference in the control group (P > 0.05). In conclusion, this work has developed a model system to monitor lateral forces and has shown that instrument design and operator usage affect dentine removal from a root canal wall.

Analysis of Variance↗
PubMed2004

Nonsurgically retreated root filled teeth--radiographic findings after 20-27 years.

AIM: To identify periapical changes in nonsurgically retreated root-filled teeth 20-27 years after root canal treatment. METHODOLOGY: From an original material of 429 roots, retreated by undergraduate students in a teaching clinic, 112 roots in 70 individuals could be evaluated radiographically 20-27 years after treatment. The same roots had been studied 10-17 years earlier. The periapical condition was registered and compared by three observers in two series of intraoral radiographs taken 10-17 and 20-27 years after treatment. A retrospective analysis was performed to gain information about probable endodontic and nonendodontic reasons for extractions of lost roots, by evaluating their periapical status immediately after retreatment and at the 10-17-year follow-up. RESULTS: Favourable outcomes were observed in 11 roots that had radiolucencies at the 10-17-year follow-up. Eight of these roots had periapical pathosis preoperatively, five of them filled with surplus root filling material. The percentage of cases recorded as normal condition at the final follow-up was 95.5%, including five cases initially recorded with increased width of the apical periodontal space. Delayed healing as a result of surplus root filling material explained most of the cases with favourable outcome assessed many years after treatment. Twenty-eight roots were lost because of extraction during the observation period, 17 during the last 10 years. Based on status at previous follow-ups, endodontic failure seems to represent a minor reason for extraction in the material. CONCLUSION: Late periapical changes, with more successful cases, were recorded when a 10-17-year follow-up after root canal treatment was extended for another 10 years. Persistent asymptomatic periapical radiolucencies, especially those with overfill, should generally not be classified as failures, as many of them will heal after an extended observation period.

Dental Pulp Cavity↗
PubMed2004

Assessment of a contrast medium as an adjunct to endodontic radiography.

AIM: To assess if a contrast medium improved diagnostic yield of endodontic radiographs. METHODOLOGY: Forty-five extracted mandibular premolar teeth were radiographed in bucco-lingual and mesio-distal planes. Access cavities were prepared, pulpal tissue extirpated and Ultravist contrast medium introduced under pressure. Radiographs were retaken and the teeth cleared following perfusion with India ink. Three examiners assessed all the films for: number of roots, number of root canals, curvature of root and/or root canal, presence of lateral canals, presence of a single foramen or apical delta and the presence or absence of canal obstructions. The examiners' interpretations were compared with the anatomy revealed by clearing. RESULTS: Kappa scores were calculated for each of the examiners, for each set of radiographs, to assess the level of intra- and inter-examiner agreement. Only moderate agreement was found throughout (kappa = 0.40-0.61). For multiple root canals a false-positive result was significantly more likely with contrast (P < 0.05). The use of contrast did not significantly improve the sensitivity of diagnosis of lateral canals or a single apical foramen. Contrast significantly increased the risk of falsely perceiving lateral canals (P < 0.002). Overall there was no statistically significant difference in the overall assessment of the anatomy of the root canals using contrast or plain radiographs (P > 0.2). CONCLUSIONS: Plain film radiographs confidently predict the presence of root or canal curvature but apical anatomy was assessed accurately in only 46% of cases. Plain radiographs were insensitive in assessing the number of root canals present, the presence of lateral canals and the occurrence of canal obstructions. The use of Ultravist contrast medium to improve diagnosis of root canal morphology of premolars is not supported.

Bicuspid↗
PubMed2005

The effect of application time of EDTA and NaOCl on intracanal smear layer removal: an SEM analysis.

AIM: To verify, under the scanning electron microscope (SEM), the influence of irrigation time with ethylenediaminetetraacetic acid (EDTA) and sodium hypochlorite (NaOCl) on intracanal smear layer removal. METHODOLOGY: Twenty-one extracted human permanent teeth with single straight root canals were included. The root canals of the teeth were instrumented and, at the end of preparation, were irrigated with 3 mL of 15% EDTA, followed by 3 mL of 1% NaOCl for 1 min (group 1), for 3 min (group 2), and for 5 min (group 3). The canals of teeth in group 4 (control) did not receive the final irrigation. The teeth were sectioned longitudinally and prepared for an SEM. The dentinal wall of cervical, middle and apical thirds was graded according to the amount of debris and smear layer remaining on the walls. The results were analysed using the Kruskal-Wallis and Conover-Inman tests. RESULTS: In all the canals of experimental groups irrigation with EDTA and NaOCl completely removed the smear layer from the cervical and middle thirds. In the apical third, the dentine surface were partially covered, particularly in the teeth of group 1, where there was significantly more smear layer when compared with the other thirds in the same group (P<0.007). However, the Kruskal-Wallis test showed overall that there were no significant differences between groups 1, 2 and 3 (P>0.05). CONCLUSION: In this limited laboratory study, canal irrigation with EDTA and NaOCl for 1, 3 and 5 min were equally effective in removing the smear layer from the canal walls of straight roots.

Chelating Agents↗
PubMed2005

Influence of cervical preflaring on apical file size determination.

AIM: To investigate the influence of cervical preflaring with different instruments (Gates-Glidden drills, Quantec Flare series instruments and LA Axxess burs) on the first file that binds at working length (WL) in maxillary central incisors. METHODOLOGY: Forty human maxillary central incisors with complete root formation were used. After standard access cavities, a size 06 K-file was inserted into each canal until the apical foramen was reached. The WL was set 1 mm short of the apical foramen. Group 1 received the initial apical instrument without previous preflaring of the cervical and middle thirds of the root canal. Group 2 had the cervical and middle portion of the root canals enlarged with Gates-Glidden drills sizes 90, 110 and 130. Group 3 had the cervical and middle thirds of the root canals enlarged with nickel-titanium Quantec Flare series instruments. Titanium-nitrite treated, stainless steel LA Axxess burs were used for preflaring the cervical and middle portions of root canals from group 4. Each canal was sized using manual K-files, starting with size 08 files with passive movements until the WL was reached. File sizes were increased until a binding sensation was felt at the WL, and the instrument size was recorded for each tooth. The apical region was then observed under a stereoscopic magnifier, images were recorded digitally and the differences between root canal and maximum file diameters were evaluated for each sample. RESULTS: Significant differences were found between experimental groups regarding anatomical diameter at the WL and the first file to bind in the canal (P < 0.01, 95% confidence interval). The major discrepancy was found when no preflaring was performed (0.151 mm average). The LA Axxess burs produced the smallest differences between anatomical diameter and first file to bind (0.016 mm average). Gates-Glidden drills and Flare instruments were ranked in an intermediary position, with no statistically significant differences between them (0.093 mm average). CONCLUSIONS: The instrument binding technique for determining anatomical diameter at WL is not precise. Preflaring of the cervical and middle thirds of the root canal improved anatomical diameter determination; the instrument used for preflaring played a major role in determining the anatomical diameter at the WL. Canals preflared with LA Axxess burs created a more accurate relationship between file size and anatomical diameter.

Analysis of Variance↗
PubMed2005

SEM analysis of the integrity of resected root apices of cadaver and extracted teeth after ultrasonic root-end preparation at different intensities.

AIM: To compare the integrity of root apices of cadaver and extracted teeth after resection, ultrasonic root-end cavity preparation at medium and low ultrasonic power settings and retrieval. METHODOLOGY: Root canal treatment, perpendicular root-end resection and root-end preparation were performed on single-rooted anterior and premolar teeth (49 teeth in situ in maxillary and mandibular jaws from cadavers and 45 extracted teeth). Apical root-end cavities were prepared with the S12/90 degrees D tip and the Suni-Max ultrasonic unit (Satelec, Merignac, France) at the intensity prescribed by the manufacturer (power 7 at power mode S) (34 cadaver teeth, 30 extracted teeth) and at a lower intensity (power 4 at power mode S) (15 cadaver teeth, 15 extracted teeth). After ultrasonic preparation the cadaver teeth were retrieved from the jaws. Exaflex impressions (GC Corporation, Tokyo, Japan) were made of the root apices after resection, root-end preparation and retrieval. These impressions were processed for SEM analysis, and the recordings evaluated for cracks and marginal chipping. RESULTS: In general, extracted teeth showed significantly more cracks and chipping than cadaver teeth. Lowering the ultrasonic power from medium to low intensity resulted in equal scores for cracks on extracted teeth and for chipping on cadaver teeth, in higher scores for cracks on cadavers and in lower scores for chipping on extracted teeth. Complete cracks and cracks originating from the root surface occurred only in extracted teeth. CONCLUSIONS: The number of cracks and degree of chipping caused by ultrasonic root-end preparation was higher on extracted teeth than on cadaver teeth. Lowering the ultrasonic power from medium to low intensity cannot be recommended as it resulted in more cracks and equal chipping on cadaver teeth. Investigation of techniques and materials should be conducted in situ and not on extracted teeth.

Apicoectomy↗
PubMed2005

Continued root formation of a pulpless permanent incisor following root canal treatment: a case report.

AIM: To present a case of a pulpless permanent incisor that continued root formation following root canal treatment. SUMMARY: A healthy 8-year-old girl with a history of dental trauma resulting in a coronal fracture involving enamel, dentine and pulp was referred by her general dental practitioner for treatment and evaluation of tooth 21. The tooth had a necrotic pulp and periapical rarefaction was evident radiographically. The canal was prepared, dressed with Ca(OH)2 and then filled with a rolled gutta percha cone and Roth's root canal sealer. A radiograph exposed eight years post-treatment, showed evidence of continued apical formation. KEY LEARNING POINTS: *Teeth with necrotic pulps and periapical rarefaction may show evidence of continued apical formation after root canal treatment. *Hertwig's epithelial root sheath may be more resistant than expected to trauma and infection.

Child↗
PubMed2005

Anatomic Endodontic Technology (AET)--a crown-down root canal preparation technique: basic concepts, operative procedure and instruments.

AIM: To illustrate the conceptual basis and the operative procedure of the Anatomic Endodontic Technology (AET) technique and to illustrate the specific instruments used in each phase. SUMMARY: The basic characteristics of the AET technique are reported. The instruments and procedure are described in three phases: coronal access, coronal-middle preparation and apical preparation. In the first phase, correct cavity design is described. In the coronal-middle phase, the use of four stainless steel shaping instruments, powered by a reciprocating handpiece is described, incorporating a brushing-milling action against canal walls. During the apical phase, dedicated apical stainless steel and NiTi hand instruments are used to complete the preparation. The stainless steel apical files are used with a 1/4 turn and withdrawal movement whilst the NiTi are used in 360 degrees rotary motion. KEY LEARNING POINTS: Most current canal shaping techniques do not prepare all the canal walls and can result in over-enlargement in some areas. AET defines three regions of the canal: coronal (from the cavo-surface of the access cavity), coronal-middle, and apical. Coronal-middle instrumentation is undertaken with four mechanically driven stainless steel shaping instrument used in brushing-milling action against canal walls. Apical preparation is completed by hand and with the formation of a stop.

Dental Alloys↗
PubMed2006

Preserving pulpal health of a geminated maxillary lateral incisor through multidisciplinary care.

AIM: To report the multidisciplinary care of an unaesthetic geminated maxillary lateral incisor tooth, which allowed its preservation in the mouth. SUMMARY: Preoperative examination of an unsightly geminated maxillary lateral incisor (tooth 22) demonstrated two pulp chambers and open apices, with normal pulp sensitivity responses. At surgery, a periodontal mucoperiosteal flap was reflected and the distal part of the geminated tooth was removed. The exposed root canal of the preserved tooth was sealed with mineral trioxide aggregate (MTA). The extraction socket and osseous defect was grafted with decalcified freeze-dried bone allograft (DFDBA) before flap closure. During follow-up, distal caries in tooth 22 and a diastema between tooth 22 and 23 were managed with composite resin restorations. Forty-two months postoperatively, normal thermal and electrical pulp sensitivity tests confirmed pulp health. Convincing apexogenesis and dentinogenesis of the developing root was confirmed by radiographic examination. Acceptable periodontal health including 3-4 mm clinical probing depths was achieved. Optimizing aesthetics and occlusion was accomplished without orthodontic treatment.

Aluminum Compounds↗
PubMed1995

Periodontal bone loss of teeth with metal posts. A radiographic study.

Periodontal bone loss was compared in teeth with metal posts and contralateral teeth without metal posts by means of intraoral radiographs. 250 subjects with a high standard of dental awareness and a great number of teeth retained were included in the study. The periodontal bone loss was calculated from the ratio of the distance from bone margin to apex (bone height) and the distance from crown tip to apex (tooth length). Intra-individual differences between experimental and control teeth were statistically analyzed with the Student paired t-test. 96 subjects (38%) had > or = 1 teeth with root posts. In all, 172 teeth with posts were found, i.e., on average 1.8 teeth per subject. The means +/- SEM of the ratio bone height to tooth length in experimental and control teeth were 0.52 +/- 0.007 and 0.56 +/- 0.006, respectively. The difference was statistically highly significant (P < 0.001). Statistically significant differences were found for incisors, premolars and molars. Regression analysis indicated more severe bone loss for teeth with longer posts. The results suggest that the periodontal bone support of teeth with metal posts is inferior to that of teeth without metal posts.

Adult↗
PubMed1997

Selection of the most accurate method of conventional radiography for the assessment of periodontal osseous destruction.

The purpose of the present study was to compare the radiographic measurements of periodontal osseous destruction with the surgical measurements, which represent the true value of osseous destruction, and to select the most successful method of conventional radiography in detecting and accurately assessing periodontal osseous destruction. A total of 5072 proximal surfaces in 2536 teeth of 100 patients with periodontitis were evaluated surgically during periodontal flap surgery and radiographically by using periapical and panoramic radiography. Comparative evaluation of the measurements obtained by these 3 different methods of osseous destruction assessment revealed the following. (1) The radiographic detection ability of small osseous destruction (1-4 mm) was very low for both methods of assessment and became even lower for the initial osseous destruction (1 or 2 mm). (2) Periapical radiography was more successful than panoramic in the detection of osseous destruction, especially of the small destruction (4.7x). (3) Panoramic radiography underestimated the osseous destruction, whereas periapical radiography was relatively accurate in the osseous destruction assessment. (4) Periapical radiography was more accurate in the osseous destruction assessment than panoramic, regardless of the location of the dental surfaces (jaw, tooth group, mesial or distal) and the degree of osseous destruction. (5) The deviation of the radiographic measurements of osseous destruction from the surgical measurements, as well as the difference between the two radiographic methods, depended on the jaw location, the tooth group and the degree of osseous destruction. (6) The radiographic assessment of osseous destruction underestimated the osseous destruction in initial periodontitis, it was relatively accurate in moderate periodontitis, but overestimated it in severe periodontitis. The radiographic measurements of osseous destruction deviated least from the surgical measurements in the group of moderate periodontitis and most in that of severe osseous destruction. (7) The 2 radiographic methods agreed most in the assessment of osseous destruction in the severe periodontitis group and least in the initial periodontitis group. (8) The indirect Schei method was less successful in detecting the small osseous destruction and less accurate in assessing the osseous destruction than the direct millimetric method of radiographic evaluation. (9) The osseous destruction as assessed from periapical radiographs by the Schei method was not significantly different from that assessed by the radiopaque Fixot-Everett grid. The results of the present study suggest that periapical radiography is more successful in detecting periodontal osseous destruction and more accurate in assessing it than panoramic radiography.

Adolescent↗