Papers by Theodor Lambrianidis
Balkan Journal of Dental Medicine, 2016
Aim: to evaluate the amount of debris extruded apically as well as the time needed for removal of... more Aim: to evaluate the amount of debris extruded apically as well as the time needed for removal of root canal filling material using ProTaper, MTwo, REndo NiTi rotary retreatment systems and handfiles. Materials and methods: 60 freshly extracted human single-rooted teeth were instrumented with Protaper files and obturated with gutta-percha and MTA Fillapex sealer with the cold lateral compaction technique. Teeth were then randomly assigned to 4 groups. ProTaper, MTwo, REndo rotary retreatment systems and Hedstroem hand files were utilized for root canal filling removal. Debris extruded apically was collected into pre-weighed vials. The weight of the dry extruded debris was established by subtracting the pre-retreatment and post-re treatment weight of vials. Time needed for reaching WL, complete removal of gutta-percha and total retreatment time were also recorded with a stopwatch. The data obtained were analyzed using One-way ANOVA (the level of significance was set at P=0.05). Resul...
Hellenika stomatologika chronika. Hellenic stomatological annals
The delicate manipulations necessary for the management of a fractured instrument using an orthog... more The delicate manipulations necessary for the management of a fractured instrument using an orthograde and/or a surgical approach include the risk of creating additional complications that might jeopardize the treatment outcome. These include: 1. Complications during and following orthograde attempts 2. Complications during and following surgical attempts
Hellenika stomatologika chronika. Hellenic stomatological annals
Management of Fractured Endodontic Instruments
Several parameters have been implicated in the fracture process of root canal instruments. Factor... more Several parameters have been implicated in the fracture process of root canal instruments. Factors such as the operator’s skill and proficiency, the shape of the access cavity, the anatomy of the root canal, the design and manufacturing of the instrument, the motors used to drive the instruments and their particular operating parameters, the instrumentation technique, the existence of a glide path, the number of uses, the sterilization method, and the corrosion by irrigants have attracted the attention of both clinicians and researchers. Most of the available evidence concerns rotary nickel-titanium instruments, while very few studies have analyzed the fracture of stainless steel files. Contradictory findings are not uncommon due to the wide variation in the methodology of the studies and the large number of confounders involved, but, overall, the operator and the root canal anatomy appear to be the most influential parameters.
Therapeutic options for the management of fractured instruments include no intervention, non-surg... more Therapeutic options for the management of fractured instruments include no intervention, non-surgical (orthograde, conservative) management, surgical management, and tooth extraction.
Hellenika stomatologika chronika. Hellenic stomatological annals
International Endodontic Journal, 1991
The aim of this study was to evaluate the effect of surface demineralization on the healing of 12... more The aim of this study was to evaluate the effect of surface demineralization on the healing of 120 replanted teeth in fifteen S-to 16-month-old dogs. Replanted teeth were divided into two groups (A and B). In group A, teeth were replanted following planing of the entire root surface. In group B, teeth were replanted following planing and surface demineraiization with citric add. Replanted teeth were splinted for 7 days, and observation periods were 3,14 and 56 days. A total of 95 teeth and their surrounding tissues were examined histologically under a light microscope. Histological examitiation of specimens 3 days after replantation revealed that initial reunion between the root and the alveolar periodontal ligament fibres was via a fibrin-like network in both groups. Fourteen days after replantation histological observations showed superior healing in group B with regard to epithelial condition, periodontal ligament fibre reatuchment to the root surface, resorption and functional arrangement of the periodonul ligament fibres. By 56 days after replantation, healing was superior in group A; group B was characterized by severe inflammatory and replacement resorption. These results indicated that surface detnineralization had in initial positive effect, but later led to impaired healing.
Clinical Oral Investigations, 2011
The aim of this study was to estimate the prevalence of transmigrant canines in a sample of panor... more The aim of this study was to estimate the prevalence of transmigrant canines in a sample of panoramic radiographs of a random Greek population, to classify them and evaluate clinically and radiographically all the implications for adjacent teeth. Panoramic radiographs of 3,586 patients retrieved from eight private practices between 1998 and 2009, were examined. Panoramic radiographs with extracted canines were not included in this study. An impacted canine was considered to be transmigrant when at least part of its length had crossed the midline. Six radiographs exhibited transmigrant canines (0.17% of the total sample of panoramic radiographs), of which four were mandibular and two maxillary. Canine transmigration is a rare phenomenon in Greek population. The impact of transmigrant canines on adjacent teeth varied from inclination, calcific metamorphosis and root resorption to no effect. Orthodontic therapy was the treatment of choice for two of the cases, while in the remaining cases the patients were scheduled for periodic recalls. Clinical and radiographic evaluation and early diagnosis are crucial aids in proper treatment planning.
The removal of a fractured instrument is influenced by factors related to the type of the tooth a... more The removal of a fractured instrument is influenced by factors related to the type of the tooth and particularly the anatomy of the root and the morphology of the root canal with the fragment especially its cross-sectional shape and diameter, the location of the fragment in relation to the canal orifice, and the existing curvature. It is universally recognized that the location of the fragment in relation to the curvature of the root canal is the main determinant, rather than the method used to retrieve it. The material, the type, and the length of the fragment are among the parameters influencing its removal. The operator’s knowledge and dexterity, the armamentarium available, and the familiarity with the chosen technique are key influencing factors. Last but not least, the patient’s anatomical factors and cooperativeness are also parameters influencing management of fractured instruments.
Introduction: To investigate Ca(OH)2 extrusion from the apical foramen in relation to the placeme... more Introduction: To investigate Ca(OH)2 extrusion from the apical foramen in relation to the placement mode. Methods: 200 teeth, prepared with ProTaper files with and without apical patency, were divided in Groups A and B respectively, and filled with Ca(OH)2 at 1 and 3 mm short of working length, using K-files manually and with mechanical spiral techniques (Pastinject/Lentulo) at 500 and 700rpm. Extrusion was graded as present/absent. Experimental categories were compared using Fisher’s exact test. Results: Extrusion was observed only in teeth with patency. There was no extrusion with K-files in all cases and with Pastinject and Lentulo inserted at 3 mm short of working length. Speed elevation did not significantly increase the extrusion cases. Conclusions: K-files tend to be safer than mechanical techniques. Pastinject and Lentulo at 3 mm short of working length prevented Ca(OH)2 extrusion. Raising speed from 500 to 700 rpm did not significantly increase the extrusion risk.
Management of Fractured Endodontic Instruments
In most cases fractured instruments do not present diagnostic problems, with the exception of ret... more In most cases fractured instruments do not present diagnostic problems, with the exception of retreatment cases where the fragment in some instances might be “hidden,” obscured by root filling material and not very clearly visible. The recognition of remaining fragments is important for treatment planning. This involves the need to choose between various acceptable nonsurgical orthograde and surgical options. Evaluating, analyzing, and comparing the performance of the techniques proposed for the management of intracanal fractured endodontic instruments are important prerequisites for the selection of the most appropriate strategy and for the prediction of the outcome. For the best modality of treatment, good clinical judgment and experience in assessing objective findings are absolutely essential.
Endodontics Dental Traumatology, Mar 31, 1988
Concurrent pulpal and periodontal disease has been described as the outcome of the pathogenetic i... more Concurrent pulpal and periodontal disease has been described as the outcome of the pathogenetic interactions between the pulp and the periodontium. Although the existence of primary endodontic lesions with secondary periodontal involvement, as well as that of "true" combined ones has been undoubtedly justified, some controversy and confusion still exist over primary periodontal lesions with secondary endodontic involvement. In this article, theoretical communicable pathways between pulp and periodontal ligament, which can be responsible for the extension of the primary periodontal inflammatory lesion in the pulp, are described. Furthermore, a re-evaluation of the pulpal invasion phenomenon is presented, based on recent research and clinical findings that demonstrate that no constant relationship between the depth of the periodontal pocket and the status of the pulp has ever been found.
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2010
Her chief complaint was a gradually increasing swelling in the left side of her maxilla, during t... more Her chief complaint was a gradually increasing swelling in the left side of her maxilla, during the preceding 2 months. After clinical examination, the radiologic and computerized tomographic scan examinations revealed the presence of a radiopaque foreign material in contact with the apex of tooth #22, confined within the limits of a radiolucent area. On dental anamnesis and after communication with her dentist, it was concluded that calcium hydroxide was deliberately extruded for the healing of the large lesion. The patient was scheduled for periapical surgery. The histopathologic features of the lesion revealed the presence of a periapical cyst and the absence of foreign body giant cells. After an observation period of 1 year, healing was uneventful. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2010;109:e86-e91)
Oral Surgery, Oral Medicine, Oral Pathology, Oral Radiology, and Endodontology, 2008
The aim of the study was to assess the prevalence of radiopacities in the jaws of a Greek populat... more The aim of the study was to assess the prevalence of radiopacities in the jaws of a Greek population sample. Study design. Panoramic radiographs of 3,513 patients retrieved from 10 practices in Northern Greece were examined for the presence of radiopacities without the knowledge of the medical histories. Of the initial sample size, 47 radiographs were excluded owing to technical errors. Descriptive characteristics of radiopacities including shape, size, and location, as well as information concerning the tooth involved and the adjacent and opposing teeth, were recorded. All analyses were performed using SPSS software. The Pearson chi-squared test was used to examine the distributions of gender, shape, size, and location. Results. A total of 72 radiopacities were identified in 69 patients (1.96% of the total sample of panoramic radiographs), showing a greater predilection in the mandibular premolar-molar region (78.3% of radiopacities observed); 44.9% of the radiopacities were associated with intact teeth or teeth with shallow filling/caries, whereas 26.1% were associated with heavily decayed/filled teeth. One-half of the radiopacities identified were circular, and the diameter varied from 1 to 2 cm. Conclusion. The results indicate the rarity of radiopacities (1.96%) in the Greek population sample that was examined and the predilection for their occurrence in the jaws. (Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2008;106: e38-e43)
International Endodontic Journal, 1994
The purpose of this investigation was to compare in V iiro the sealing ability of root canal trea... more The purpose of this investigation was to compare in V iiro the sealing ability of root canal treatments performed in situ with injected thermopiasticized guttapercha compared with the lateral condensation technique. Thirty single-rooted teeth with straight canals, due for extraction for orthodontic or periodontal reasons were prepared using a step-back technique. Teeth were then divided randomly into groups A and B and obturated, respectively, with the sectional injection thermopiasticized gutta-percha and the lateral condensation techniques. Teeth were extracted after 15 days, immersed in India ink for 3 days and the leakage was determined using area-metric analysis. The roots were ground transversally and the root portion was incrcmentaly removed with successive steps of 250 pjn each, up to the coronal level of the dye penetration. Everj' section was photographed with a stereoscopic microscope under the same magnification (X 20); 310 photographs were taken. Measurements of the area covered by ink as well as the whole cross-sectional area of the canal were made from each photograph with the aid of a digitizing computer. The measurements were subjected to non-parametric statistical analysis. No significant difference vvas found (P>0.05). The technique of lateral condensation proved to be better in the first five sections (1.2 mm from the foramen) while thermopiasticized gutta-percha technique was superior in the rest of the root canal.
International Endodontic Journal, 2002
To examine pH changes in the cervical external root surface, when calcium hydroxide was used as a... more To examine pH changes in the cervical external root surface, when calcium hydroxide was used as a supplementary barrier to the protective base material during intracoronal bleaching. Twenty-eight single-rooted human premolars extracted for orthodontic reasons were instrumented with K-Flex files, obturated with gutta-percha and subjected to thermocatalytic bleaching. The teeth were divided into four groups. In group A, a glass-ionomer cement barrier was placed at the cemento-enamel junction (CEJ) level and in group C, the barrier was placed 1 mm apical to the CEJ. In groups B and D, Ca(OH)2 was placed in contact and apical to the glass-ionomer cement at the CEJ and 1 mm apical to the CEJ, respectively. The teeth were placed in vials containing distilled water and the pH values of the medium surrounding the teeth were recorded after 1, 2, 4, 10 and 15 days, following renewal of the medium. The pH in the medium became acidic in all groups. No statistically significant differences existed between groups for all the experimental days (P = 0.790). The placement of Ca(OH)2 as a supplementary barrier during intracoronal bleaching did not have a significant effect in reversing the acidic pH created at the external root surface in vitro. Its potential effect during these procedures in vivo needs to be further investigated.
Dental Traumatology, 1989
Abstraet-Xeroradiography is a highly accurate electrostatic imaging technique. In this teehnique ... more Abstraet-Xeroradiography is a highly accurate electrostatic imaging technique. In this teehnique a eonventional singlephase dental x-ray unit is used as an x-ray souree, but instead of a silver-halide film image, a uniformly charged selenium alloy plate housed in a light-proof eassette is used. In this article the equipment, proeedure, properties and artifacts related to the xeroradiographic technique are described. An evaluadon of the xeroradiographie images is also presented. Xeroradiography, xA^hich requires only about one-third of the dose required for conventional radiographs, is a valuable alternative to conventional radiography for detecting carious lesions, calculus deposits and periodontal disease. It is also of value in interpreting periapieal structures. •=''-.''': ' ' ' • " ' > :" .
Dental Traumatology, 1985
Abstraet-This study was designed to examine observer variations in radiographic interpretations o... more Abstraet-This study was designed to examine observer variations in radiographic interpretations of periapicai conditions after endodontic therapy and when assessing the quality of the seal of root canal fillings. Radiographs of 90 teeth with 143 roots and 160 root canals, satnpled at ratidom from endodonticaliy treated teeth, were evaluated by 9 dentists (3 endodontist, 3 oral radiologists, 3 general practitioners). Film interpretations were made independently by each observer and they were asked to complete pre-designed forms where the eriteria for the interpretation were noted. Nine weeks later the same radiographs were evalualecl by 2 pairs of examiners, each pair consisting of 1 endodontist and 1 general practitioner. Complete agreement among all 9 individual observers was found in 38% of cases for the periapicai conditions aticl in 41% for the quality of the seal. The corresponding figures for the pairs of examiners were 65% and 57%, respeetively.
Dental Traumatology, 1996
Swallowing or aspiration of a foreign body is a complication that may arise from any procedure in... more Swallowing or aspiration of a foreign body is a complication that may arise from any procedure in the oral cavity performed without the use of a rubber dam. Two cases of swallowed endodontic instruments and possible complications are presented. Emphasis is given in the discussion on the early diagnosis and treatment and primarily on prevention with the use of rubber dam, an absolute essential during endodontic treatment.
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Papers by Theodor Lambrianidis