Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Retreatment”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

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

At least 217 records · Page 12Linked to original sources
PubMed2004

Postoperative pain after endodontic retreatment: single- versus two-visit treatment.

OBJECTIVE: The purpose of this clinical study was to determine the effect of 1- or 2-visit root canal treatment on the postoperative pain in the retreatment cases. STUDY DESIGN: Two hundred eighteen cases that required retreatment were included in the study. Obturated and unfilled canal space and the status of periapical tissues were evaluated according to the PAI index. The patients were subcategorized in regard to the presence or the absence of preoperative pain. Approximately half of each category was treated in 1 appointment. After removing the previous root canal obturation materials and biomechanic preparation of root canals, the teeth in the 1-visit group were obturated at the first appointment by using AH 26 sealer and laterally compacted gutta-percha, and those in the 2-visit group were medicated with calcium hydroxide-chlorhexidine combination and then closed with a temporary filling material. One week after the initial appointment, patients were asked about the occurrence of postoperative pain. The level of discomfort was rated as no pain, mild pain, moderate pain, or severe pain (flare-up). Data were statistically analyzed using the chi-squared and Fischer exact tests. RESULTS: Eight patients from the 1-visit group and 2 patients from the 2-visit group had flare-ups. There was a statistical difference between the groups (P <.05). Two-visit root canal treatment was more effective in completely eliminating pain than 1-visit treatment of previously symptomatic teeth (P <.05). CONCLUSIONS: Two-visit endodontic treatment with intracanal medication was found to be effective in reducing postoperative pain of previously symptomatic teeth and decreased the number of flare-ups in all retreatment cases.

Bismuth↗
PubMed1998

Risk assessment of the toxicity of solvents of gutta-percha used in endodontic retreatment.

Three randomly assigned groups of single-canaled extracted teeth obturated with gutta-percha were retreated using controlled application of one of three organic solvents: chloroform, xylene, or halothane. Two additional groups of teeth served as positive and negative controls. Residual volume of solvent expressed through the apical foramen during retreatment was determined by the difference of pretreatment and posttreatment weights of hermetically sealed receptacles attached to the root surface of the teeth. Results indicate that the amount of solvent that has been determined to have leached out through the apical foramen is several orders of magnitude below the permissible toxic dose. Thus, it is proposed that the use of any of the aforementioned solvents used in the retreatment of root canals would pose negligible risk to the patient.

Chloroform↗
PubMed1998

In vitro study of a Nd:YAP laser in endodontic retreatment.

Nd:YAP laser is a dental laser with a 1340 nm wavelength. The laser beam is carried by a 200 to 300 microns fiberoptic and is suitable for endodontic therapy. We used the Nd:YAP laser in an in vitro experiment to study its effectiveness in endodontic retreatment. Temperature measurements and irradiation parameters were first defined. Then Nd:YAP laser irradiation was used, alone or in combination with hand instruments, to remove various canal sealers and broken instruments. Clinical parameters were monitored and scanning electron microscopic observations were conducted. When used at 200 mJ--with a pulse duration of 150 ms, an exposure time of 1 s and a frequency of 10 Hz--Nd:YAP laser preserved the dentinal walls of the root canal and enabled root canal retreatment without thermic elevation harming periodontal tissue. It is concluded that, in combination with hand instruments, the Nd:YAP laser is an effective device for root canal preparation in endodontic retreatment.

Dental Pulp Cavity↗
PubMed2001

Calcium hydroxide in endodontic retreatment after two nonsurgical and two surgical failures: report of a case.

AIM: To describe the role of calcium hydroxide in infection control during complex endodontic retreatment. SUMMARY: A case is presented in which two conventional endodontic treatments and two surgical interventions failed to bring periapical healing. Despite this history, a further conventional treatment augmented by long-term disinfection with calcium hydroxide finally delivered a successful outcome. KEY LEARNING POINTS: Periapical healing follows proper intracanal infection control. Despite repeated surgical and nonsurgical intervention, careful retreatment can often bring healing. Calcium hydroxide has long-acting antimicrobial and soft-tissue dissolving activity. It is a helpful adjunct in endodontic retreatment.

Calcium Hydroxide↗
PubMed2000

Effectiveness of ProFile .04 taper rotary instruments in endodontic retreatment.

This study investigated the retreatment effectiveness of .04 Taper nickel-titanium rotary ProFiles. Thirty extracted single-rooted anterior teeth were instrumented and obturated with gutta-percha/Roth's Sealer using lateral condensation. They were distributed into three groups of 10 each. Retreatment for group A was done using Profile alone, group B using Profile and chloroform, and group C using hand files with chloroform. The teeth were then split longitudinally into halves. The remaining gutta-percha/sealer on the root canal wall in the cervical, middle, apical thirds, and the whole canals were visually scored with the aid of light microscopes. The results showed that the mean scores in groups A and B were generally lower (better) than group C. Mean scores of the apical thirds tended to be higher (worse) than the middle and the cervical thirds, except in group A. ProFile with or without chloroform seemed to be a viable alternative retreatment method.

Analysis of Variance↗
PubMed2000

Effects of the Nd:YAP laser on coronal restorative materials: implications for endodontic retreatment.

With new wavelengths that allow light transmission by optical fibers, the laser is now often used in endodontics either during treatment or retreatment. The aims of this study were to (i) specify the effects of laser irradiation on restorative materials in terms of topographic effects and (ii) describe different protocols for the first steps of retreatment. The laser used in this study was an optical fiber Nd:YAP (Lokki dt, Vienne, France) with a wavelength of 1.34 microns. Samples of the following restorative materials were prepared: amalgam, composite, permanent and temporary cements, and prosthodontic alloy. The handpiece of the Nd:YAP laser was fixed perpendicular to the surface of the different preparations. All trials were performed with the fiber tip either in contact with or at a distance of 2 mm from the material. The surface effects in all cases were (i) the creation of craters in the center of the lased areas, (ii) a border of fusion material at the edge of the craters, and (iii) cracks or fractures at a distance from the target areas. For the cements, amalgam and composite, the effects included a projection of material from the center to the edge of the lased area and/or the apparent photovolatization of light particles. For all materials the laser induced deeper absorption in the areas of direct contact than when it was held at a distance. This suggests that the fiber should be in contact with the restorative material for lasing in the straight part of the canal when the objective is either to pass through the material or alongside it between material and tooth. If the practitioner cannot determine the direction of the curve of the canal, lasing should be performed at a distance to weaken the material and thus permit more efficient use of an ultrasonic device. Lasing should in all cases be performed under close X-ray monitoring. Provided that sufficient caution is used, the laser may be helpful in removing restorative materials during retreatment.

Absorption↗
PubMed2004

Treatment outcome in endodontics: the Toronto study. Phases I and II: Orthograde retreatment.

The 4- to 6-year outcome of orthograde retreatment was assessed for Phases I and II of the Toronto Study. In total, 523 teeth in 444 patients were retreated. With 395 teeth lost to follow-up and 25 extracted, 103 teeth (34% recall) were examined by two independent, blinded, calibrated examiners for outcome: "healed" (absence of apical periodontitis, signs, or symptoms) or "diseased" (presence of apical periodontitis, signs, or symptoms). The "healed" rate (81%) differed significantly for preoperative apical periodontitis (absent, 97%; present, 78%) and perforation (absent, 89%; present, 42%). Logistic regression revealed an increased risk of disease for preoperative perforation and adequate root filling quality, and postoperative lack of definitive restoration (odds ratios = 26.5, 6.6, and 14.0, respectively). Without perforation, inadequate intraoperative root filling length was also identified (odds ratio = 6.8). This study suggested that apical periodontitis, although a strong predictor, was secondary to preoperative perforation and root filling quality, and to postoperative restoration, in predicting the outcome of retreatment.

Adult↗
PubMed2004

Levels of evidence for the outcome of endodontic retreatment.

The purpose of this investigation was 2-fold: (a) to complete a thorough search of published literature related to clinical studies on the success and failure of nonsurgical retreatment, and (b) to assign levels of evidence to these publications. Clinical studies related to success and failure of retreatment since 1970 were identified using both electronic and manual literature searches. After identification of pertinent literature, each article received a level of evidence (LOE) from one (high) to five (low). Thirty-one clinical studies and six review articles related to this subject were identified. There was no LOE 1 Randomized Control Trials (RCT). There were three LOE 2 RCTs, one LOE 2 Cohort, and two LOE 3 Case Control Studies. Thirteen Case Series (LOE 4), which comprise the most highly quoted success and failure data, were found. Twelve Case Reports (LOE 5) and six review articles (LOE 5) were found. Based on these findings, it appears that few high level studies have been published in the past 34 yr related to the success and failure of endodontic retreatment.

Dental Restoration Failure↗
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↗
PubMed2006

Effectiveness of hand and rotary instrumentation for removing a new synthetic polymer-based root canal obturation material (Epiphany) during retreatment.

AIM: To evaluate the effectiveness of hand and rotary instrumentation for removal of vertically compacted Epiphany and gutta-percha during retreatment. METHODOLOGY: Sixty extracted single-rooted maxillary central incisors were enlarged to size 40 using FlexMaster instruments. The teeth were randomly divided into four groups of 15 specimens each. The canals of two groups were obturated using vertically compacted Epiphany. The others were filled with vertically compacted gutta-percha and AH Plus sealer. One Epiphany group and one gutta-percha group was reinstrumented with Gates Glidden burs and Hedström files. In the other two groups, obturation material was removed using Gates Glidden burs and RaCe rotary instruments. After clearing the roots, the area of remaining obturation material on the root canal wall was measured using a computer image analysis program. Statistical analysis was performed using Repeated Measures Analysis of Variance and anova. RESULTS: Retreatment of specimens obturated with gutta-percha showed significantly more remaining obturation material than specimens filled with Epiphany (P < 0.05). No difference was found between the removal with Hedström files and with RaCe instruments (P > 0.05). Regarding the mean time of retreatment and time required for reaching the working length, Hedström files were significantly faster than RaCe instruments (P < 0.05). The times did not depend on the kind of obturation material (P > 0.05). CONCLUSIONS: Vertically compacted Epiphany in combination with Epiphany Root Canal Sealant was removed more effectively than gutta-percha and AH Plus sealer. Hedström files were more rapid than RaCe rotary instruments.

Dental Pulp Cavity↗
PubMed2006

Retreatment efficacy of hand versus automated instrumentation in oval-shaped root canals: an ex vivo study.

AIM: To compare the efficacy of hand versus automated instrumentation when retreating oval-shaped root canals. METHODOLOGY: Sixty human premolars with single oval canals were instrumented and filled with gutta-percha and sealer and divided into three groups (n = 20)--group 1: ProFile .04 taper rotary instruments; group 2: Anatomic Endodontic Technology (AET), and group 3: manual instrumentation with Hedström files. The teeth were split longitudinally and gutta-percha/sealer remnants in the coronal, middle and apical thirds were assessed with light microscopy. The mean percentage of gutta-percha/sealer remnants for each group was calculated and statistically analysed for significance using an ANOVA repeated measures (P < 0.001) and Tukey's multiple comparison test. The time required for retreatment was analysed using a one-way ANOVA and Tukey's test (P < 0.001). RESULTS: Overall, 10-18% of the canal walls were covered with gutta-percha/sealer remnants after preparation using any technique. Statistical analysis demonstrated that the mean values for remnants of filling material in the ProFile group were significantly higher than for the other groups (P < 0.001), except in the apical third where no significant difference occurred. In all groups, the mean values in the middle third were higher than the coronal and apical thirds. The retreatment time for ProFile and AET was significantly shorter compared to manual instrumentation with Hedström files (P < 0.001). CONCLUSIONS: Under the experimental conditions, AET instruments and manual instrumentation with Hedström files resulted in cleaner canals. However, completely clean root canal walls were not produced with any of the techniques investigated.

Bicuspid↗
PubMed1996

Endodontic retreatment: a rational approach to non-surgical root canal therapy of immature teeth.

The specificity of retreating immature teeth involves generally a broadly wide open apex and/or an inverted root canal conicity (apical opening wider than the root canal orifice), a periapical pathology leading often to a continuous canal exudation and thin and fragile dentinal walls. Nonsurgical endodontic retreatment of immature teeth consists at first in removing coronal and root canal iatrogenic obstructions in order to regain total canal patency. Apexification is then the treatment of choice, preceding a final gutta-percha obturation. The present article outlines a step-by-step rational approach to the root canal retreatment of immature teeth, pertaining to their biomechanical and pathological specificity.

Calcium Hydroxide↗
PubMedDate not supplied

Interferon-alpha-2b and ribavirin for retreatment of chronic hepatitis C.

BACKGROUND/AIMS: Subjects with chronic hepatitis C who fail treatment with interferon-alpha are generally divided into two groups: "relapsers" who normalized serum aminotransferase activity and have undetectable viral RNA during treatment and "non-responders" who do not achieve these results. The aim of this study was to examine retreatment of such subjects. METHODOLOGY: We studied 117 subjects with chronic hepatitis C who failed treatment with interferon-alpha, 87 of whom were "non-responders" and 30 "relapsers." Retreatment was with either interferon-alpha-2b plus ribavirin for 48 weeks or with interferon-alpha-2b plus placebo for 24 weeks followed by 24 weeks of combined therapy. RESULTS: Sustained response rates, defined as undetectable viral RNA in serum 6 months after retreatment, were 53% in "relapsers" and 10% in "non-responders" (P < 0.005). There was no significant difference if ribavirin was given for 24 or 48 weeks. In "non-responders" infected with genotypes other than type 1, 42% achieved a sustained response compared to 5% infected with genotype 1 (P = 0.027; odds ratio 7.09). CONCLUSIONS: Treatment with interferon-alpha-2b plus ribavirin is effective in approximately 50% of "relapsers" and "non-responders" infected with non-type 1 genotypes of hepatitis C virus. This therapy is only marginally effective in "non-responders" infected with genotype 1a or 1b.

Adult↗
PubMed2003

The major factors that influence endodontic retreatment decisions.

The presence of a new or persistent periapical radiolucency adjacent to a rootfilled tooth is often used as a criterion of endodontic treatment "failure". However, clinicians' suggested management of such cases is subject to substantial interindividual variation. Several components that might influence endodontic retreatment decision making have been explored, but data on which factors dentists actually think they consider, are missing. The aim was to interview 20 general dental practitioners (GDPs) and 20 endodontists about factors they thought would influence the prescription of endodontic retreatment. Six simulated cases were presented as cartoons accompanied with a clinical history. In two of the cases the teeth were planned to serve as an abutment tooth in a fixed prosthodontic construction. The status of the periapical bone tissue and the quality of rootfilling seal were varied. Between 1 and 6 factors per case were reported to influence decision making. In cases not planned to serve as abutment teeth most dentists considered that the periapical condition was the most important factor, whilst they considered the fixed prosthodontic construction to be the most important factor in cases planned as abutment teeth. Generally, endodontists seem to be more inclined to retreat and act on the mere presence of a periapical lesion regardless of size than GDPs. In a real clinical setting in direct contact with patients, additional factors like economy and patients' preferences might be expected to exert a major influence. The majority of the dentists stated that they thought that their colleagues would make similar decisions as they did themselves.

Attitude of Health Personnel↗
PubMedDate not supplied

Tolerability of retreatment with omalizumab, a recombinant humanized monoclonal anti-IgE antibody, during a second ragweed pollen season in patients with seasonal allergic rhinitis.

Two randomized, placebo-controlled, double-blind studies have shown clinical benefit with omalizumab (Xolair), a recombinant humanized monoclonal anti-immunoglobulin E (IgE) antibody, at a dose of 300 mg every 3 or 4 weeks in patients with seasonal allergic rhinitis. The present open-label, 12-week study was designed to assess the safety and tolerability of retreatment with omalizumab in 287 patients previously treated with this agent in one of the latter studies. Omalizumab, 300 mg, was administered subcutaneously every 4 weeks (three injections) to patients with IgE levels < or = 150 IU/mL (n = 182) and every 3 weeks (four injections) to patients with IgE levels > 150 IU/mL (n = 105) at screening before retreatment. Reported adverse events were monitored and blood samples were analyzed for laboratory safety (hematology and serum chemistry) and IgE levels. Urinalysis also was completed as part of the laboratory safety evaluation. The overall incidence and pattern of adverse events were similar to those reported in the primary study. There were no severe or serious adverse events related to omalizumab treatment and no anti-omalizumab antibodies were detected in any patient. Two patients withdrew from treatment because of adverse events (skin rash and nausea; facial erythema and edema) related to study treatment. Free IgE levels decreased to the levels associated with symptom reduction in the core study. In summary, retreatment during a second pollen season with omalizumab, 300 mg every 3 or 4 weeks, was well tolerated and was not associated with any significant immunologic reactions.

Adolescent↗
PubMed2004

Retreatment of chronic hepatitis C virus infection.

Despite advances in antiviral therapy for chronic hepatitis C, approximately half of patients undergoing initial treatment fail to achieve a sustained virologic response (SVR), thus prompting consideration of retreatment with alternative regimens. The decision to re-treat should be based on the severity of liver disease, as well as the presence of clinical and virologic predictors of a successful outcome of additional therapy. Retreatment of patients who were prior nonresponders to interferon monotherapy with interferon plus ribavirin results in SVR rates of 13% to 15%, which can be increased to 25% to 40% if peginterferon plus ribavirin is used. Retreatment of patients who were prior nonresponders to interferon plus ribavirin with peginterferon plus ribavirin unfortunately achieves SVR rates of approximately 10%. The growing number of patients who have been treated and have failed initial therapy highlights the need for the development of more efficacious antiviral agents for the treatment of chronic hepatitis C.

Antiviral Agents↗
PubMed2005

Acquisition of drug resistance in multidrug-resistant Mycobacterium tuberculosis during directly observed empiric retreatment with standardized regimens.

The risk of acquiring additional drug resistance in strains of multidrug-resistant tuberculosis (MDR-TB) during failure of empiric standardized retreatment regimens is poorly defined. We sought to estimate this risk by comparing drug susceptibility profiles and RFLP patterns of paired MDR-TB isolates collected from 27 patients before and after retreatment failure. Among 23 patients with paired isolates with concordant RFLP patterns, 19 (83%) had become resistant to at least one additional drug after failed retreatment. In this limited group of MDR-TB patients, acquisition of resistance was common during failure of empiric drug regimens. Further study is needed to confirm these findings.

Adolescent↗
PubMed2005

[Treatment of benign prostatic hyperplasia (BPH) by transurethral needle ablation (TUNA) and 36-month follow-up of the retreatment rate].

OBJECTIVE: Benign prostatic hyperplasia (BPH) is a disease affecting about 25% of men over the age of 40. One half of these men report symptoms that interfere with their daily activities. MATERIAL AND METHODS: In this multicentre study, 102 patients with BPH were treated by transurethral needle ablation (TUNA). The efficacy of treatment was evaluated for 12 months after the operation by means of Madsen and IPSS (International Prostate Symptom Score) scores. The course of uroflowmetry and quality of life (International Score) and sexual function were also assessed for one year. The safety of treatment was evaluated according to the type and frequency of complications. The results show an immediate and significant improvement of symptoms (p < 0.0001 for Madsen and IPSS scores and maximum flow rate between M0 and M12) demonstrating the efficacy of the TUNA system. A very positive impact of TUNA was demonstrated on quality of life. No negative impact was reported on sexual function and the operation had very few repercussions with a low adverse event rate. The retreatment rate (surgical and/or drug) was evaluated 36 months after the operation by means of an optional follow-up questionnaire subsequently completed by the investigators. RESULTS: After 3 years, based on the 80 questionnaires returned, 43 patients (53.8%) were stable and did not need any other medical or surgical treatment for BPH. Thirty-seven (37) patients (46.3%) required retreatment: 21 were treated with drugs (26%), 17 were treated surgically (21.25%) including 1 patient who was also retreated with drugs. This study demonstrates the significant and lasting improvement of BPH symptoms by TUNA, which constitutes an alternative attractive to surgery in young patients and/or patients worried about their sexuality.

Catheter Ablation↗