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PubMed1990

Comparison of the Canal Master endodontic instrument and K-type files for enlargement of curved root canals.

Twenty mandibular molars with 40 mesial curved root canals were instrumented with a circumferential technique using K files and the Canal Master instrumentation technique by junior dental students whose only endodontic experience had been completion of a preclinical endodontic course. Preoperative and postoperative radiographs were taken facially and mesially with instruments in place. The canals were evaluated radiographically for transportation 1 mm and 4 mm from the apex. The mesial roots were cross-sectioned at the same level. The sections were evaluated for roundness of the canal preparation. It was concluded that the Canal Master instrumentation technique transported the root canal less and produced rounder preparations than the K file circumferential technique. There appears to be a greater tendency for breakage with the Canal Master.

Dental Pulp Cavity↗

PubMed2001

Root canal filling of endodontically treated teeth by dentistry students in clinical offices from 1996 to 1998--radiological results.

UNLABELLED: THE PURPOSE of our study was to evaluate radiologically the degree of root canal filling of teeth treated by students. METHODS: 724 segment radiographs with an overall number of 1142 canals were examined. The level of root canal filling was measured from the radiographic apex. The objects of the study were divided into three groups: 1. canals filled to more than 2 mm from the apex; 2. canals filled up to 2 mm from the apex; 3. canals filled to the radiographic apex; 4. overfilled canals. The objects from the second and the third group were combined as a group of successfully filled canals. RESULTS: The results showed 62.90% of successfully filled canals, 27.80% of the canals were filled more than 2 mm from the radiological apex and 9.30% - with overfilling. The greatest percentage of canals filled more than 2 mm from the apex refers to the mesial and vestibular canals of the molars, and after them the most frequently obturated canals are those of single-root teeth (57.94%). CONCLUSIONS: The results obtained allow us to estimate the endodontic treatment of the students as good. The greatest difficulties are encountered in filling the vestibular and mesial canals of the molars.

Dental Pulp Cavity↗

PubMedDate not supplied

[Today's trends in endodontics].

Some new means and innovative operative techniques in the field of endodontics are presented that have been developed and perfected over time. Instruments such as the operative microscope, ultrasonography, miniaturised tools for surgery, new materials such as mineral trioxide aggregate (MTA) should become part of the daily routine of the endodontist. For example, the operative microscope plays a role in diagnosing pulp damage after removal of deep caries; in orthograde endodontics in diagnosing perforations; alongside ultrasonography in the search for calcified canals, removal of pins (screw-type, fibre, etc.) and also in positioning MTA. In all these cases, the operative microscope is used discontinuously, alternating working and observation phases. In endodontic surgery, the operative microscope is on the contrary used continuously, enabling the surgeon to observe details of anatomy of the root apex at high magnification, and above all enabling positioning of canal obturation with perfect seal. It is clear that the operative microscope used in all surgical phases will enable complete management of the operation and facilitate the endodontist in observing the operative field, otherwise very difficult to control.

Dental Instruments↗

PubMed1994

Transmigration of mandibular canines: a review of the literature and report of two cases.

Transmigration of mandibular canines across the midline is rare. Two 14-year-old female patients from South India were found to exhibit this phenomenon. In one patient, the mandibular right canine had crossed the midline and migrated to the left, up to the mesial root apex of the permanent first molar, near the lower border of the mandible. In the other patient, the permanent mandibular left canine had crossed the midline and migrated up to the root of the mandibular right canine. Both of these patients are being observed regularly for further migration. The literature on this rare condition is reviewed and its etiologic possibilities and treatment modalities are discussed.

Adolescent↗

PubMed1993

Innervation of root dentine in human premolars.

Based on autoradiographic studies it is generally held that the mammalian root dentine is only sparsely innervated. Previous electron microscopic studies on human teeth did not reveal nerve fibres beyond radicular predentine. It is the purpose of this communication to provide ultrastructural evidence for the presence of nerve fibres in apical root dentine of human premolars. Two healthy mandibular second premolars, removed due to orthodontic reasons, which formed part of a previous study, were utilized for this investigation. Root discs of about 0.6 mm thickness were removed at about 2 mm cervical to the root apex and processed for light and electron microscopy. Transmission electron microscopic examination revealed numerous nerve fibres along the pulp-predentine border and in patches of predentine. Distinct nerve fibres were observed in the inner mineralized portion of the radicular dentine. The axons existed in close association to the odontoblastic processes, but no synaptic contacts or junctional complexes could be observed.

Axons↗

PubMed1987

Influence of the enlargement of the apical foramen in periapical repair of contaminated teeth of dog.

Root canals of dogs' premolar teeth were exposed to contamination and to the development of periapical inflammation over a period of 45 days. Root canals were overinstrumented 2 mm beyond the apical foramen with file No. 60 and were underfilled by 2 to 3 mm short of the roentgenographic apex. Ninety days after endodontic treatment, healing and ingrowth of connective tissue into the root canal occurred in 67.8% of the cases. These results suggest that the diameter of the apical foramen and the intensity of the canal contamination are determining factors for periapical tissue repair in cases of pulpal necrosis.

Animals↗

PubMedDate not supplied

Dental histology: study of aging processes in root dentine.

The amount of sclerotic root dentine increases with age, proceeding from the apex towards the crown. There are obvious optical changes in the tissue, which becomes translucent (dentine is normally opaque). Therefore, the sclerosis of root dentine could be a reliable indicator of age in anthropological studies of human remains. We studied the histological aspects of sclerotic dentine in longitudinal thin sections (70-140 microns) of undecalcified premolars, cut in the bucco-lingual plane. To quantify the sclerosis and to construct a reference standard, we sectioned 85 premolars from subjects of known age (70 from odontological extractions and 15 from a university collection). Another 10 teeth from medieval subjects were studied to assess the applicability of the method to ancient skeletal collections. The technique consists of embedding the tooth in a polyester resin (cold method), sectioning it with a diamond blade microtome. Qualitative analysis was performed with polarized light microscopy and measurements were made with a quote 2D x,y viewer and on digital images. The sclerotic root dentine was quantified with both linear and surface area parameters in order to assess the correlation with age. The quality of the sections was sufficient for the clear discernment and quantification of the sclerotic dentine. Indeed, the technique allowed us to obtain good results with a considerable saving of time and money compared with other dental histological techniques. The best correlation with age was obtained from the surface area parameter, particularly after exclusion of the cementum and pulp chamber. To produce comparable data from similar studies, we advise the use of cold resins, as used here, and digital computerized analyzers because of their accuracy, precision and quickness. The qualitative analysis of the ancient teeth indications that this dental aging techniques can be applied to both recent and ancient dental tissues.

Adolescent↗

PubMed2004

Three-dimensional assessment of morphologic changes of the maxilla: a comparison of 2 kinds of palatal expanders.

Previous studies of the morphologic changes of the maxilla after palatal expansion have used 2-dimensional methodologies. In the present study, we used a 3-dimensional surface laser scanning technique and computerized cast analysis, in addition to analysis of anteroposterior cephalograms, to assess the morphologic changes of the palate by 2 kinds of expanders: tissue borne (Haas; n = 9) and tooth borne (Hyrax; n = 10). Cast analysis demonstrated that, although all patients started treatment with similar malocclusion, treatment outcomes were different depending on the appliance used. Both appliances generated maxillary expansion (ie, improved mean surface area, mean intermolar linear distance, and mean perimeter) (P <.05). However, the appliances performed differently to achieve the final expansion. Haas appliances demonstrated a greater orthopedic movement (ie, improvement of the mean interpalatal distance) (P <.05), and Hyrax appliances demonstrated dentoalveolar expansion by increasing the mean palatal angulation of the alveolus (P <.05). Anteroposterior cephalometric analysis showed that both appliances increased mean maxillary width and mean intermolar distance significantly (P <.05). On the other hand, differences in nasal cavity width and upper incisal apex distance were not statistically significant (P >.05). This new 3-dimensional methodology proved useful for comparing treatment outcomes by evaluating the morphologic changes induced by palatal expansion and generated a better visualization of these outcomes.

Adolescent↗

PubMed1995

[Lesions of the inferior alveolar nerve during extraction of the wisdom teeth. Consequences--prevention].

Neurological consequences of extractions of the third inferior molar can be severe. Progress in imaging techniques has made it possible to identify molars << at risk >>. Extraction by wear without removal of the apex is proposed as a means of avoiding damage to the alveolar nerve. If no surgical prophylaxy is used the risk is major sequellae: painful anaesthesia of the area involved. There is no really effective treatment for such sequellae, creating persistent psychological problems throughout life.

Cranial Nerve Diseases↗

PubMed2004

Prognosis of intentional replantation of vertically fractured roots reconstructed with dentin-bonded resin.

There is no particular treatment established to preserve vertically fractured teeth. We evaluated the long-term prognosis of the intentional replantation of 26 vertically fractured roots after reconstruction with 4-META/MMA-TBB dentin-bonded resin. Replanted teeth were evaluated according to clinical criteria and radiographic examinations for periods ranging from 4 to 76 months. Eighteen cases were functional and retained, with six fully successful; the others needed further observation. Eight cases failed to respond to treatment because of refracture, recurrence of gingival inflammation, or both. Longevity was calculated as 88.5% at 12 months after replantation, 69.2% at 36 months, and 59.3% at 60 months. All failures occurred in premolar and molar teeth. Longitudinal fractures extending more than 2/3 from the cervical portion toward the apex showed significantly shorter longevity compared with fractures within the 2/3 area (log-rank test, p = 0.02). Intentional replantation of vertically fractured roots reconstructed with dentin-bonded resin may be considered for incisors as an alternative to extraction, although the long-term success is not optimal.

Adult↗

PubMed2005

Prevalence of apical periodontitis and the quality of endodontic treatment in an adult Belarusian population.

AIM: To estimate the prevalence of teeth with apical periodontitis (AP) and technically failed root fillings in an adult Belarusian population. METHODOLOGY: Panoramic radiographs of all 1423 patients over 15 years of age not seeking emergency dental care, and attending the Dental School of the Belarusian Medical University for the first time during the period from 1 January to 31 December 2001 were examined. The quality of root fillings was scored according to criteria of length proposed by De Moor et al. [International Endodontic Journal 33 (2000) 113] and the periapical status of all teeth (except third molars) was categorized on the basis of presence or absence of radiographic signs of AP. The data were analysed using the chi-square test and odds ratio. RESULTS: Radiographs indicated that 8632 teeth (22% in the maxilla; 21% in the mandible) were missing leaving a total of 31,212 teeth to be assessed. Twenty per cent of the teeth had some filling material in the root canal(s). AP was found in 1141 subjects (80%) and 12% of the teeth. AP was more frequently associated with molar teeth (23%) than premolar (14%), canine (4%) and incisor teeth (6%). AP was diagnosed in 45% of root filled teeth, the remaining cases with AP had not been root filled. Statistical analysis showed that the probability of radiological detection of AP in root filled teeth was 25-fold higher than when the root canals had not been filled (chi2 = 8636.04, P < or = 0.001, odds ratio with 95% confidence intervals: 23.01 < 25.17 < 27.45). Periapical radiolucencies with adequately filled root canals occurred significantly less often than with teeth in which the root canal was filled more than 2 mm from radiographic apex or when filling material was extruded through the apex. CONCLUSION: The prevalence of AP in all age groups in Belarus was higher than in other populations. The probability of AP increased significantly after root canal treatment and was closely correlated with the quality of the root filling.

Adolescent↗

PubMed2005

Difference in root canal length between Asians and Caucasians.

AIM: To investigate whether there is a racial difference in canal length between the Asians and Caucasians. METHODOLOGY: Five hundred and fifteen Asian patients who had received root canal treatment at the Yonsei University Hospital, Korea between 1995 and May 2001 and 324 Caucasoid patients who had received root canal treatment at the Graduate Endodontic Clinic at the University of Pennsylvania, US were selected. The clinical endodontic procedures at both clinics were similar. An electronic apex locator (Root-ZX; J. Morita Co., Kyoto, Japan) was used to measure the initial working lengths and this was verified by conventional radiography. The measurements from both Asian and Caucasian teeth were compared using a Student's t-test and a Mann-Whitney test. RESULTS: The mean difference in canal length of pooled teeth between the Asian and Caucasian teeth was 1.2 mm, with a range from 0 to 2.5 mm. The greatest difference was in the distobuccal canal (2.5 mm) of maxillary first molar teeth followed by the mesiolingual canal (2.3 mm) of mandibular second molar, the buccal canal (2.1 mm) of the maxillary second premolar, the maxillary first molar and the mandibular second molar. CONCLUSION: Tooth lengths in Asians were shorter than Caucasians.

Asian People↗

PubMed1991

Clinical evaluation of the accuracy of the Evident RCM Mark II Apex Locator.

The accuracy of the Evident RCM Mark II in locating the apical foramen was evaluated in 37 human teeth scheduled for extraction. After extraction, the difference between the position of the apical foramen determined electronically and its real anatomical location was measured under a binocular microscope, using a micrometer mobile in x, y, and z coordinates. The results show that in 86% (n = 37) of the cases, an accurate location +/- 0.5 mm of the apical foramen was obtained.

Adolescent↗

PubMed1982

A cephalometric evaluation of hard- and soft-tissue changes during the third stage of Begg treatment.

This study examined the effect of lingual root torque during the third stage of Begg treatment upon the maxillary central incisor, hard-tissue Point A, and soft-tissue Point A. Lateral cephalograms were taken, at the beginning and end of Stage III, of eighteen patients undergoing Begg treatment. Linear and angular measurements were made in an attempt to find the anteroposterior changes which occurred in the above structures as well as the superior-inferior changes which occurred in the maxillary first molar and the maxillary central incisor. It was found that the apex of the maxillary incisor, Point A, and soft-tissue Point A moved posteriorly a significant amount following Stage III mechanics. Also, the incisal edge of the maxillary central incisor moved anteriorly and extruded significantly. Weak correlations between hard- and soft-tissue changes may be due to changes in thickness of the upper lip related to growth and to growth of the nose.

Adolescent↗

PubMed2005

A radiographic assessment of progressive loading on bone around single osseointegrated implants in the posterior maxilla.

OBJECTIVES: The aim of this clinical study was to determine the effectiveness of progressive loading procedures on preserving crestal bone height and improving peri-implant bone density around maxillary implants restored with single premolar crowns by an accurate longitudinal radiographic assessment technique. MATERIALS AND METHODS: Twenty-three HA-coated, endosseous dental implants were placed in 20 subjects and permitted to heal for 5 months before surgical uncovering. The implants were randomly assigned to either an experimental or control group. Following a conventional healing period, the control group implants were restored with a metal ceramic crown and the experimental group implants underwent a progressive loading protocol. The experimental group was progressively loaded by increasing the height of the occlusal table in increments from a state of infraocclusion to full occlusion by adding acrylic resin to a heat-processed acrylic crown. The progressively loaded crowns were placed in infraocclusion for the first 2 months, light occlusion for the second 2 months, and full occlusion for the third 2 months. At this point, a metal ceramic crown replaced the acrylic crown. Standardized radiographs of each implant were made at the time of restoration, then after 2, 4, 6, 9, and 12 months of function. Digital image analysis and digital subtraction radiography were used to measure changes in crestal bone height and peri-implant bone density. RESULTS: The mean values of crestal bone height loss at 12 months were 0.2+/-0.27 mm for the progressively loaded implants and 0.59+/-0.27 for the conventionally loaded implants, and when tested with repeated-measure ANOVA across the time periods, the differences were statistically significant (P< or =0.05). The progressively loaded group showed a trend for higher bone density gain in the crestal area than the conventionally loaded group, but the conventionally loaded group showed a trend for higher bone density gain at the apex of the implants. CONCLUSION: The peri-implant bone around progressively loaded implants demonstrates less crestal bone loss than the bone around implants placed conventionally into full function. The peri-implant density measurements of the progressively loaded implants show continuous increase in peri-implant bone density by time.

Alveolar Process↗

PubMed1991

The effect of post space preparation on the apical seal of root fillings using chemically adhesive materials.

The effect on the apical seal of root filling teeth with two sealer cements that reacted chemically with tooth structure was studied in vitro. In addition, apical leakage of teeth obturated with these materials and subsequently prepared to accept a post was tested. Ninety single-rooted teeth with mature apices were prepared chemomechanically by the stepback technique using files and copious irrigation with 2.5 per cent sodium hypochlorite. The teeth were then randomly allocated to six groups of 15 teeth each. Two groups were root filled by lateral condensation of gutta-percha and one of three sealer cements: Tubliseal, a radiopaque glass ionomer luting cement, Ketac Cem, and a chemically active composite resin, Panavia Ex. Thirty minutes later, in one group for each material, a post space was prepared leaving 4-5 mm of root filling at the apex. The extent of apical leakage in each group was determined after immersion in Indian ink for 14 days. The teeth were demineralized, dehydrated and immersed in methyl salicylate, which rendered them transparent, and a linear measurement of dye penetration was recorded. No statistically significant difference in the extent of leakage was found between the sealers in those groups which were filled by lateral condensation and left intact. However, the degree of leakage increased after post space preparation with the glass ionomer and Tubliseal groups, but was reduced in the Panavia Ex group.

Coloring Agents↗

PubMed1976

Reddening of the upper central incisors associated with periapical granuloma in lepromatous leprosy.

Four years after starting treatment for lepromatous leprosy in England a male Pakistani aged 26 was found to have red discoloration of the upper central incisor teeth. A radiograph suggested periapical abscess on the right with haziness in a corresponding area on the left. Right apicectomy was performed with removal of a solid mass attached to the apex, sections revealing a lepromatous infiltrate with acid-fast fragments of Mycobacterium leprae in the cytoplasm of foamy macrophages. Clinical and archaeological evidence for the frequent involvement of these teeth in lepromatous leprosy is reviewed. The upper incisor area is relatively cool, a factor which may be of critical importance for the lodgement and multiplication of this bacillus, as it is in other body sites in lepromatous leprosy.

Adult↗

PubMed1993

Intentional replantation of endodontically treated teeth.

This article reports 31 cases of intentional replantation with an overall success rate of 80.6% with six recorded failures. Survival times varied from 1 day to 22 years. A second mandibular molar that failed after 3 weeks was replanted successfully a second time with no signs of failure after a 46-month follow-up period. Two cases of intentional replantation of deciduous molars are also reported. We suggest that intentional replantation reduces adverse outcomes and should be considered as another treatment modality and not as a procedure of last resort. This procedure is recommended as the treatment of choice in the following instances: for lower second molars, for single-rooted teeth, and lower first molars when there is difficulty in accessibility to perform apical surgery; when the mental foramen is superimposed over the apex of the premolars; when the molar apex is in proximity to the mandibular canal; when patients object to periradicular surgery; when failures occur after apical surgery, or when surgery would create a periodontal pocket as a result of extensive bone removal. Periradicular surgery with a retroseal is more advantageous for first molars when roots are more curved, widespread, and are more prone to fracture compared with second molars whose roots are more tapered and close together.

Contraindications↗