Comparison between PAI and quantitative digital radiographic assessment of apical healing after endodontic treatment

Identification of a MarR Subfamily That Regulates Arsenic Resistance Genes

In this study, comprehensive analyses were performed to determine the function of an atypical MarR homolog in Achromobacter sp. strain As-55. Genomic analyses of Achromobacter sp. As-55 showed that this marR is located adjacent to an arsV gene. ArsV is a flavin-dependent monooxygenase that confers resistance to the antibiotic methylarsenite [MAs(III)], the organoarsenic compound roxarsone(III) [Rox(III)], and the inorganic antimonite [Sb(III)]. Similar marR genes are widely distributed in arsenic-resistant bacteria. Phylogenetic analyses showed that these MarRs are found in operons predicted to be involved in resistance to inorganic and organic arsenic species, so the subfamily was named MarR_ars. MarR_ars orthologs have three conserved cysteine residues, which are Cys36, Cys37, and Cys157 in Achromobacter sp. As-55, mutation of which compromises the response to MAs(III)/Sb(III). GFP-fluorescent biosensor assays show that AdMarR_ars (MarR protein of Achromobacter deleyi As-55) responds to trivalent As(III) and Sb(III) but not to pentavalent As(V) or Sb(V). The results of RT-qPCR assays show that arsV is expressed constitutively in a marR deletion mutant, indicating that marR represses transcription of arsV. Moreover, electrophoretic mobility shift assays (EMSAs) demonstrate that AdMarR_ars binds to the promoters of both marR and arsV in the absence of ligands and that DNA binding is relieved upon binding of As(III) and Sb(III). Our results demonstrate that AdMarR_ars is a novel As(III)/Sb(III)-responsive transcriptional repressor that controls expression of arsV, which confers resistance to MAs(III), Rox(III), and Sb(III). AdMarR_ars and its orthologs form a subfamily of MarR proteins that regulate genes conferring resistance to arsenic-containing antibiotics. IMPORTANCE In this study, a MarR family member, AdMarR_ars was shown to regulate the arsV gene, which confers resistance to arsenic-containing antibiotics. It is a founding member of a distinct subfamily that we refer to as MarR_ars, regulating genes conferring resistance to arsenic and antimony antibiotic compounds. AdMarR_ars was shown to be a repressor containing conserved cysteine residues that are required to bind As(III) and Sb(III), leading to a conformational change and subsequent derepression. Here we show that members of the MarR family are involved in regulating arsenic-containing compounds.

Retrospective clinical evaluation of root canal treatment with or without photodynamic therapy for necrotic teeth and teeth subjected to retreatment

PURPOSE

To compare the effect of photodynamic therapy (PDT) as a procedure to complement root canal treatment (RCT), for both primary treatment and retreatment.

METHODS

This was a retrospective study based on analysis of clinical records. A total of 214 teeth that had undergone RCT on either a primary or retreatment basis, with or without complementary PDT, were evaluated. For 118 teeth that met the previously established inclusion criteria, the time until healing was evaluated. Complementarily, the need for application of calcium hydroxide (CaHy) between visits and the number of visits necessary for completing the treatment were assessed. Data were analyzed using the Mann-Whitney and χ² tests with a significance level of P < 0.05.

RESULTS

Periapical radiolucency resolution was achieved at 15 ± 9.33 months in the RCT + PDT group and 20.35 ± 22.1 months in the RCT group (P = 0.07). For primary treatment, CaHy was necessary in 72.4% of the RCT cases and 16.4% of the RCT + PDT cases (P < 0.01). For retreatment cases, CaHy was used in 82.7% of the RCT cases and 17% of the RCT + PDT cases (P < 0.01). In the RCT group, more than two visits were necessary for primary treatment in 18.6% of the cases, compared with 13.10% in the RCT + PDT group (P = 0.31), whereas for retreatment, more than two visits were necessary for 64.9% and 49.1% of cases, respectively (P = 0.05).

CONCLUSION

In comparison with RCT alone, teeth receiving RCT + PDT showed less variation in the time needed for periapical lesion healing, fewer cases required CaHy, and fewer cases required more than two visits to complete the treatment.

Two-dimensional Periapical, Panoramic Radiography Versus Three-dimensional Cone-beam Computed Tomography in the Detection of Periapical Lesion After Endodontic Treatment: A Systematic Review

Radiographic imaging is a common resource for endodontic diagnosis, treatment, and prognosis. Two-dimensional (2D) periapical and digital panoramic radiographs often showed image distortion; this issue was resolved with the emergence of three-dimensional (3D) cone-beam computed tomography (CBCT). This review examines the accuracy of various radiographic techniques in the assessment of periapical lesion after endodontic treatment. Our goal was to determine whether a 2D radiograph (periapical and panoramic) is as accurate as a 3D radiograph (i.e., CBCT) in the assessment of periapical lesion after endodontic treatment. We searched the electronic databases Medline and Cochrane and trial registries for ongoing trials. We included both retrospective and prospective studies comparing the efficacy of periapical healing with various radiographic techniques after endodontic treatment. The outcome of interest was the percentage detection of periapical lesions and periapical healing assessment after endodontic treatment. All data were collected using a specially designed extraction form. We assessed the risk of bias in the studies using the Cochrane tool for diagnostic tests (QUADAS). We judged two studies to be at low risk and two to be at moderate risk of bias. Although there was a difference in the percentage detection of periapical healing efficacy by various radiographic techniques, all studies reported that CBCT had higher accuracy in the detection of periapical lesions compared to periapical and panoramic radiography. The next best choice is periapical radiographs, followed by panoramic radiographs as they provide better visualization and accuracy.

Long-term Outcomes of Endodontic Treatment Performed with Resilon/Epiphany

INTRODUCTION

Resilon (Resilon Research LLC, Madison, CT) with Epiphany Sealer (Pentron Clinical Technologies, Wallingford, CT) was introduced into the market in 2004 as a new method of root canal obturation. This material as well as the traditionally used gutta-percha with AH Plus sealer (Dentsply Maillefer, Tulsa, OK) were in use over a 9-year span in the University of North Carolina endodontic clinics. Although Resilon was initially thought to create a "monoblock" seal between the material and the canal, in vitro studies later suggested this concept not to be true. The long-term outcome of Resilon using a validated radiographic index and a systematic approach has not been reported. The purpose of this retrospective cohort study was to radiographically evaluate the outcome of Resilon/Epiphany-treated root canals compared with traditional gutta-percha/AH Plus.

METHODS

One hundred twenty-five teeth were radiographically evaluated using the periapical index; 80 were treated with Resilon and 45 with gutta-percha. Age, sex, tooth position, and number of months to follow-up were documented, and a multivariate analysis with odds ratio was performed.

RESULTS

Resilon-treated teeth were 5.3 times more likely to have a periapical index of 3 to 5 at follow-up compared with gutta-percha (P = .009). Teeth presenting with preoperative lesions, regardless of the material used, were also more likely to present with a lesion at follow-up (P = .04).

CONCLUSIONS

Teeth obturated with Resilon were more likely to present with a lesion at follow-up compared with gutta-percha obturated teeth after controlling for the presence of a preoperative lesion and the length to follow-up.

Association between C-reactive protein, neutrophil to lymphocyte ratio and the burden of apical periodontitis: a case-control study

OBJECTIVE

Endodontic originated chronic apical periodontitis (AP) is an inflammatory disease of periapical tissue. High-sensitivity C-reactive protein (hsCRP) as an inflammatory marker and hemogram indexes provide valuable information to clinicians for diagnosis, screening and follow-up of various diseases. The aim of this study was to investigate AP in terms of its association with hemogram indices and hsCRP levels.

MATERIAL AND METHODS

Study includes 104 patients with AP and 40 participants as the control group. 160 teeth were diagnosed as AP through digital radiographic images and scored with respect to Periapical Index (PAI) scoring. Afterwards, patients were categorized into 3 grades in accordance with both the number and the severity of AP. AP grade 0 was considered for the control group with regard to a new scoring system. Patients with only one tooth involved with AP with a PAI score of 3 or 4 were categorized as an AP Grade 1, when a patient had more than one tooth with a PAI score of 3 or 4 he was classified as an AP Grade 2 and a patient with at least one tooth scored as a PAI 5 was rated as an AP Grade 3. Hemograms and hsCRP levels were measured for each individual to establish a correlation with inflammatory markers.

RESULTS

The neutrophil/lymphocyte ratio (NLR) levels of patients with AP Grade 3 were significantly higher than all other AP grades (p < .05). hsCRP levels in patients with an AP Grade 2 and 3 were higher than both AP Grade 0 and 1 (p < .05).

CONCLUSIONS

hsCRP levels of patients were reliable predictive indicators for AP severity in correlation with the new proposed scoring system for AP.

Single Versus Multi-visit Endodontic Treatment of Teeth with Apical Periodontitis: An in vivo Study with 1-year Evaluation

Background:

Apical periodontitis (AP) is one of the most prevalent diseases of the teeth. Treatment of AP is based on the removal of the cause, i.e., bacteria from the root canals. Achievement of adequate bacterial eradication in one appointment treatment remains a controversy.

Aim:

This prospective study was conducted with the objective to compare the periapical healing of teeth with AP treated in (a) single visit versus (b) two visits, either with or without Vitapex as an intracanal medicament.

Subjects and Methods:

Patients were selected randomly from the Department of Conservative Dentistry and Endodontics. Forty-three patients (81 teeth) met the inclusion criteria, i.e., AP (both symptomatic and asymptomatic) visible radiographically size ≥2 mm × 2 mm, not suffering from any immune-compromising disease, age between 16 and 65 years and tooth not accessed previously. Patients were randomly divided into three groups, i.e., single-visit group (Group 1), multi-visit group without any intracanal medicament (Group 2), and multi-visit group with Vitapex as interim intracanal medicament (Group 3). Comparison was done radiographically using periapical index (PAI). The primary outcome measure was the change in periapical radiolucency after 1 year assessed by PAI scores. The Mann-Whitney U-test was used to evaluate differences between groups at baseline (immediate postoperative) and at the 12-month follow-up evaluation. Change in PAI score for each group from baseline to 12-month follow-up evaluation was tested with the Wilcoxon signed rank test. The secondary outcome measures, proportion of teeth in each group that could be considered improved (decreased PAI score) or healed (PAI <2), were assessed with the Chi-square test.

Results:

No statistically significant difference in periapical healing was found between three groups.

Conclusion:

After 1-year evaluation, no difference in periapical healing was found between single-visit treatment and multi-visit treatment groups with the given sample size.

Choice of diagnostic and therapeutic imaging in periodontics and implantology

Imaging forms an integral component for diagnosis of dental and in specific periodontal diseases. To date, intra-oral radiographic techniques are the main non-invasive diagnostic aids for the detection and assessment of internal changes in mineralized periodontal tissues like alveolar bone. These analog radiographic techniques suffer from inherent limitations like: Two dimensional projection, magnification, distortion, superimposition and misrepresentation of anatomic structures. The evolution of novel imaging modalities, namely cone beam computed tomography, tuned aperture CT empowered dental researchers to visualize the periodontium three dimensionally. This improves interpretation of structural and biophysical changes, ensures densitometric assessments of dentoalveolar structures including variations in alveolar bone density, and peri-implant bone healing more precisely. This detailed review, highlights current leading edge concepts, envisions a wide range of imaging modalities which pave the way for better understanding and early intervention of periodontal diseases.

Mineral trioxide aggregate as apical plug in teeth with necrotic pulp and immature apices: a 10-year case series

INTRODUCTION

This 10-year study evaluated the clinical and radiologic outcomes of teeth with necrotic pulp, immature apices, and periapical lesions treated with the mineral trioxide aggregate (MTA) apical plug technique.

METHODS

Seventeen single-rooted immature teeth with necrotic pulp and periapical lesion from 17 patients treated between January 2001 and December 2001 were included in this study. Apical obturation on all teeth included in the study was completed in 2 visits: first using calcium hydroxide as an interappointment intracanal medication and a second visit for the creation of the artificial apical barrier with MTA. The outcome, based on clinical and radiographic criteria, was assessed by 2 calibrated investigators using the periapical index (PAI). The Friedman test was used to verify the differences between baseline and the 1-, 5-, and 10-year PAI scores.

RESULTS

Of the 17 patients treated, 1 patient dropped out at 5 years. At the 10-year follow-up, 15 teeth were healed (PAI ≤2), and 1 tooth had been extracted because of the presence of a longitudinal root fracture. The PAI score exhibited a significant decrease between baseline and 1 year and between 1 and 5 years. The difference between 5 and 10 years was not significant.

CONCLUSIONS

The apical plug with MTA was a successful and effective technique for long-term management of this group of teeth with necrotic pulps with immature root development and periapical lesions.

A novel method to estimate the volume of bone defects using cone-beam computed tomography: an in vitro study

INTRODUCTION

The routine use of high-resolution images derived from 3-dimensional cone-beam computed tomography (CBCT) datasets enables the linear measurement of lesions in the maxillary and mandibular bones on 3 planes of space. Measurements on different planes would make it possible to obtain real volumetric assessments. In this study, we tested, in vitro, the accuracy and reliability of new dedicated software developed for volumetric lesion assessment in clinical endodontics.

METHODS

Twenty-seven bone defects were created around the apices of 8 teeth in 1 young bovine mandible to simulate periapical lesions of different sizes and shapes. The volume of each defect was determined by taking an impression of the defect using a silicone material. The samples were scanned using an Accuitomo 170 CBCT (J. Morita Mfg Co, Kyoto, Japan), and the data were uploaded into a newly developed dedicated software tool. Two endodontists acted as independent and calibrated observers. They analyzed each bone defect for volume. The difference between the direct volumetric measurements and the measurements obtained with the CBCT images was statistically assessed using a lack-of-fit test. A correlation study was undertaken using the Pearson product-moment correlation coefficient. Intra- and interobserver agreement was also evaluated.

RESULTS

The results showed a good fit and strong correlation between both volume measurements (ρ > 0.9) with excellent inter- and intraobserver agreement.

CONCLUSIONS

Using this software, CBCT proved to be a reliable method in vitro for the estimation of endodontic lesion volumes in bovine jaws. Therefore, it may constitute a new, validated technique for the accurate evaluation and follow-up of apical periodontitis.

A retrospective radiographic study of coronal-periapical status and root canal filling quality in a selected adult Turkish population

OBJECTIVE

To investigate the oral health (with regard to the periapical status, quality of root fillings and coronal restorations) in an urban adult Turkish subpopulation using digital panoramic radiographs.

MATERIALS AND METHODS

One thousand digital panoramic radiographs involving 28,000 teeth were selected from the archive of the Public Oral and Dental Health Center of Isparta. Coronal status (the type of restoration, signs of marginal leakage or decay), root filling quality (length and lateral seal) and periapical status (according to Periapical Index, PAI) were evaluated. Correlations between apical periodontitis (AP) and the quality of root fillings or coronal restorations were statistically analyzed using the χ(2) test.

RESULTS

Of the 28,000 teeth evaluated, 22,380 (80.0%) were sound, 4,732 (16.9%) were missing, 753 (2.6%) were filled and 135 (0.5%) were decayed. Of the 753 coronal restorations, 400 (53.1%) were radiographically acceptable. Of the 23,268 teeth, 601 (2.6%) were root filled and 247 root fillings were adequate. Ninety-five (15.8%) root-filled teeth had AP (PAI 3-5). Out of the total, the AP prevalence was 0.4% in root-filled teeth and 0.8% in teeth without root fillings. The presence of AP was significantly correlated with inadequate coronal restorations and root canal fillings (p = 0.000).

CONCLUSION

Tooth type, quality and type of coronal restorations, and length and homogeneity of root fillings significantly affected periapical status.

Pixel intensity and fractal dimension of periapical lesions visually indiscernible in radiographs

INTRODUCTION

The purpose of the study was to analyze pixel intensity (PI) and fractal dimension (FD) values in radiographs of chemically created but visually undetectable periapical lesions.

METHODS

Artificial lesions were created by applying 70% perchloric acid to the sockets of left and right first premolars in 12 cadaver mandibles. For preparation of relatively small lesions, the acid was applied for 30 and 60 minutes. Before and after each acid application, radiographs were taken (60 kVp, 7 mA, and 1.5 mm Al equivalent filtration for 0.12 second) with storage phosphor plates. An optical bench was used to standardize projection geometry. Image plates were scanned immediately after exposure, and the acquired images were saved uncompressed in TIF format. Six observers evaluated the images by using a 5-grade scale, and the images scored as "definitely absent" by all observers were used for the calculations of PI and FD. Box-counting FDs and differences in mean PI were computed for regions of interest at the apical areas of each premolar. Repeated-measures analysis of variance, Tukey test, and Pearson correlation coefficient test were used for statistical analysis.

RESULTS

A significant difference was found in FD values after both acid application periods (P < .05), whereas a difference in PI was detected only in images obtained after 60-minute acid application (P < .05). There was a negative correlation between FD and PI values (-0.754, P < .05).

CONCLUSIONS

Calculation of FD can be a tool for the early detection of periapical lesions given the presence of baseline radiographs.

Technical quality of root canal fillings done in a Nigerian general dental clinic

Background

Previous reports indicate that worldwide, the technical quality of root canal fillings is poor. There are few reports from sub-Saharan Africa and none yet from Nigeria where most patients access treatment from non-specialists especially at general dental clinics. The aim of this study was to evaluate the technical quality of root canal fillings done in a general dental clinic with emphasis on the effects of professional experience of the operator, whether tooth was anterior or posterior and whether it was a maxillary or mandibular tooth.

Methods

Retrospective study of case notes and periapical radiographs of patients with completed root canal fillings seen between 2008 and 2011. Inclusion criteria included cases of primary treatment with available case notes, good quality pre-operative and post-operative periapical radiographs. Technical quality that was assessed was root canal length and homogeneity. Root canal fillings were classified either as Good Quality Endodontic Work (GQEW) or Non- Good Quality Endodontic Work (NGQEW).

Results

Fifty-one patients aged between 8 and 54 years (mean 28) fulfilled the inclusion criteria for this study. From these, there were 62 root filled teeth giving a ratio of 1.2 root canal filled teeth per person. There were acceptable length of root canal fillings in 71% of teeth, 58.1% were homogeneous while 53.2% were GQEW. There was no statistically significant difference in whether tooth was root filled by junior or senior dentist (p = 0.43), anterior or posterior (p = 0.11). There was significant association between GQEW and maxillary teeth (p = 0.03).

Conclusion

This study showed that the overall technical quality of root canal fillings done by non-specialists was better than earlier reports but lower than that done by endodontists. Since many patients receive treatment from non-specialists in developing countries, it is necessary to improve technical quality of root canal fillings done in general dental clinics. These could be through improvement in the quality of undergraduate training and more post graduate continuing education courses for skills update.

Prevalence of apical periodontitis and quality of root canal fillings in population of Zagreb, Croatia: a cross-sectional study

AIM

To determine the prevalence of apical periodontitis and assess the quality of endodontic fillings in the population of the city of Zagreb, Croatia.

METHODS

A total of 1462 orthopantomograms from new patients at 6 different dental practices was analyzed during 2006 and 2007. The presence of periapical lesions was determined by using the periapical index score (PAI). The quality of endodontic fillings was assessed according to the filling length and homogenicity. Data were analyzed using t test and ANOVA with Scheffe post-hoc test.

RESULTS

There were 75.9% of participants with endodontically treated teeth and 8.5% of all teeth were endodontically treated. Only 34.2% of endodontically treated roots had adequate root canal filling length, while 36.2% of root canal fillings had homogenous appearance. From the total number of teeth with intracanal post, 17.5% had no visible root canal filling. Using PAI 3 as a threshold value for apical periodontitis, periapical lesions were detected in 8.5% of teeth. Adequate quality of root canal fillings was associated with a lower prevalence of periapical lesions.

CONCLUSION

We found a large proportion of endodontically treated teeth with apical periodontitis and a correlation between the quality of endodontic filling and the prevalence of periapical lesions. This all suggests that it is necessary to improve the quality of endodontic treatment in order to reduce the incidence and prevalence of apical periodontitis.

Alveolar bone changes in autogenous tooth transplantation

OBJECTIVE

To assess the alveolar bone formation after autogenous tooth transplantation by conventional radiographic method and digital subtraction radiography.

STUDY DESIGN

This retrospective study was done in 54 of 136 patients who received the third molar tooth transplantation and attended the first week, as well as the 1-, 3-, 6-, 9-, and 12-month follow-up. Postoperative periapical radiographs were subsequently evaluated by direct visual interpretation and digital subtraction radiography. The data were analyzed by using McNemar test and 1-way repeated-measure analysis of variance as well as Bonferroni multiple comparison.

RESULTS

Fifty-four cases of transplantation were studied. Most of them had normal wound healing. The direct radiographic interpretation and digital subtraction radiography found significant alveolar bone formation in the first-and the third-month follow-ups (P < .05). Lamina dura appeared in the third month and kept increasing until the sixth month.

CONCLUSIONS

Postoperative radiographs revealed the distinctive bone formation up to the third month. The clinical and radiographic assessment found that the third molar transplants could bear a normal chewing load within 3 months.

Radiographic study of the prevalence of apical periodontitis and endodontic treatment in the adult population of São Luís, MA, Brazil

This study investigated the prevalence of apical periodontitis (AP) and its association with endodontically treated teeth in residents of São Luís, MA, Brazil. Two-hundred complete series of periapical radiographs taken over a 10-year period (1993-2003) were retrieved from the files of four prosthesists and five periodontists. The Periapical Index (PAI) was used and the age range, sex, tooth groups, location and association with endodontic treatment (ET) were also analyzed. The Cohen Kappa and Chi-square tests were used for statistical analysis. Out of 200 patients, 135 presented at least one case of AP, which corresponds to a prevalence of 67.5%. Of the 5008 teeth examined, 296 had AP and 553 had ET. Therefore, considering the total number of teeth, AP and ET prevalences were 5.9% and 11%, respectively. Of the 553 endodontically treated teeth, 235 (42.5%) were associated with AP. Chi-square test showed a strong correlation between AP and ET (p<0.05). The 40-year-old age group was significantly the most prevalent (p<0.05). There was no association between AP and patient's sex (p>0.05). The maxillary incisors were the most affected group of teeth (p<0.05). AP had predilection for the maxilla and was strongly associated with endodontically treated teeth (p<0.05). The prevalence of apical periodontitis and endodontically treated teeth with AP was high and similar to the results of studies performed in other countries.

A retrospective study comparing clinical outcomes after obturation with Resilon/Epiphany or Gutta-Percha/Kerr sealer

The purpose of this retrospective study was to evaluate the treatment outcome of root canal systems obturated with gutta-percha and Kerr Pulp Canal Sealer compared with Resilon and Epiphany sealer. One hundred three teeth treated in a private endodontic practice were included in the study. Clinical outcomes (healed versus nonhealed) were assessed by using the Periapical Index determination and clinical evaluation at recall appointments. The magnitude of the association between obturation materials used and outcome measured was evaluated with univariate and multivariate logistic regression analysis. Univariate analysis indicated that pulpal vitality, presence of a preoperative lesion, and length of recall times were statistically significant in predicting the outcome. Logistic regression analysis showed that age, tooth position, and length of recall times were statistically significant in predicting the outcome. Root canal systems obturated with gutta-percha and Kerr Pulp Canal Sealer or Resilon and Epiphany sealer had statistically indistinguishable differences in clinical outcome.

Factors Affecting Outcomes for Single-Tooth Implants and Endodontic Restorations

Initial root canal therapy and implant placement are both common treatment modalities, and, as such, prognostic factors that influence the treatment outcomes of these two restorations should be identified. In a retrospective chart review, 196 implant restorations and 196 matched initial nonsurgical root canal treated (NSRCT) teeth in patients were evaluated for four possible outcomes-success, survival, survival with intervention, and failure. Results showed that smokers had fewer successes and more failures in both groups (p = 0.0001), whereas NSRCT outcomes were affected by periradicular periodontitis (p = 0.001), post placement (p = 0.013), and overfilling (p = 0.003). Outcomes for both groups were not significantly affected by diabetes, age, or gender. Implant group outcomes were not affected by implant length (from 10 to 16 mm), diameter (from 3.25 to 5.5 mm), or an adjacent endodontically treated tooth, nor were NSRCT outcomes affected by the number of appointments for the procedure.

Retrospective Cross Sectional Comparison of Initial Nonsurgical Endodontic Treatment and Single-Tooth Implants

Initial root canal treatment and the replacement of a single tooth with implants are both viable treatment options, but various success rates have been reported for each treatment modality. This study compared 196 implant restorations and 196 matched initial nonsurgical root canal treatment (NSRCT) teeth in patients for four possible outcomes- success, survival, survival with subsequent treatment intervention and failure. Cross classifications/tabulations were analyzed using Pearson's chi(2) test for association of the two classifications (endo vs. implant and outcome). Polytomous regression with likelihood ratio tests were used in testing association with tooth location and outcome. Outcomes were as follows for implants and NSRCT outcomes, respectively: success 73.5% and 82.1%; survival with no intervention 2.6% and 8.2%; survival with intervention 17.9% and 3.6%; and failure 6.1% and 6.1%. Location of the restoration in the mouth did not affect outcome. This study suggests that restored endodontically treated teeth and single-tooth implant restorations have similar failure rates, although the implant group showed a longer average and median time to function and a higher incidence of postoperative complications requiring subsequent treatment intervention.

Influence of residual bacteria on periapical tissue healing after chemomechanical treatment and root filling of experimentally infected monkey teeth

The purpose of this study was twofold: first, to determine the influence on the healing of the periapical tissues when selected bacterial strains and combinations thereof remain after root canal treatment; and, second, the relationship to healing of the quality of the root filling. In eight monkeys, 175 root canals, previously infected with combinations of four or five bacterial strains and with radiographically verified apical periodontitis, were endodontically treated, bacteriologically controlled, and permanently obturated. After 2-2.5 yr, the periapical regions were radiographically and histologically examined. Of these teeth, 48 root canals were also examined for bacteria remaining after removal of the root fillings. When bacteria remained after the endodontic treatment, 79% of the root canals showed non-healed periapical lesions, compared with 28% where no bacteria were found. Combinations of residual bacterial species were more frequently related to non-healed lesions than were single strains. When no bacteria remained, healing occurred independently of the quality of the root filling. In contrast, when bacteria remained, there was a greater correlation with non-healing in poor-quality root fillings than in technically well-performed fillings. In root canals where bacteria were found after removal of the root filling, 97% had not healed, compared with 18% for those root canals with no bacteria detected. The present study demonstrates the importance of obtaining a bacteria-free root canal system before permanent root filling in order to achieve optimal healing conditions for the periapical tissues.

Digital imaging analysis with mathematical morphology and fractal dimension for evaluation of periapical lesions following endodontic treatment

OBJECTIVE

To see if a method for digitizing trabecular pattern of bone could be used to quantitatively evaluate changes in bone pattern following endodontic treatment of teeth with periapical osteolytic lesions.

STUDY DESIGN

Periapical radiographs were digitized and further processed with mathematical morphology operations known as skeletonization. The trabecular patterns resulting from this skeletonization process were further analyzed with fractal dimension analysis using box-counting.

RESULTS

The periapical area in digitized radiographic images showed fractal behavior. Twenty-five of 27 patients showed increase of the fractal dimension after root canal treatment. Significant changes of the box-counting could be noted 3 months after root canal treatment (P < .05).

CONCLUSIONS

Mathematical morphology operation and box-counting might be helpful in early detection of changes of periapical trabecular pattern after root canal treatment.

Levels of Evidence for the Outcome of Nonsurgical Endodontic Treatment

The purpose of this systematic review was (a) to search for clinical articles pertaining to success and failure of nonsurgical root canal therapy, and (b) to assign levels of evidence to these studies. Electronic and manual searches were conducted to identify studies published between January 1966 and September 2004 with information on the success and failure of nonsurgical root canal therapy. Articles were reviewed and graded for strength of level of evidence (LOE) from one (highest level) to five (lowest level). This review resulted in the identification of 306 clinical studies related to this topic area. Six articles were randomized controlled trials (RCTs, LOE 1). This search also identified 12 low-quality RCTs (LOE 2), 14 cohort studies (LOE 2), five case-control and eight cross sectional studies (LOE 3), four low-quality cohort studies (LOE 4), and five low-quality case-control studies (LOE 4). The majority (73) of the often-quoted "success and failure" studies were case series (LOE 4). The rest of the articles were descriptive epidemiological studies (42), case reports (114), expert opinions (18), literature reviews (4), and one meta-analysis. Based on these findings, it appears that a few high-level studies have been published in the past four decades related to the success and failure of nonsurgical root canal therapy. The data generated by this search can be used in future studies to specifically answer questions and test hypotheses relevant to the outcome of nonsurgical root canal treatment.

Success of an alternative for interim management of irreversible pulpitis

BACKGROUND

Extraction and endodontic therapy are treatment options for irreversible pulpitis. Extraction often is chosen for financial reasons. The authors conducted a study to investigate an alternative interim therapy.

METHODS

The authors recruited patients (N = 73) with irreversible pulpitis and whose teeth were restorable but who opted for extraction owing to financial reasons. After undergoing pulpotomy, the teeth were restored by random assignment with one of two intermediate restorative materials: Caulk IRM (Dentsply Caulk, Milford, Del.) (Group I, n = 38) or an IRM base with glass ionomer core (Fuji IX GP, GC America, Alsip, Ill.) (Group II, n = 35). The authors monitored the teeth over six and 12 months for pain, integrity of restoration and radiographic periapical status by densitometric analysis.

RESULTS

By six months, 10 percent of subjects remaining in the study (Group I, n = 27; Group II, n = 25) reported pain; by 12 months, 22 percent (Group I, n = 22; Group II, n = 18) reported pain. A two-tailed Fisher exact test showed no significant difference (P > or = .05) between groups at either time interval. No apical radiographic change was noted in 49 percent of teeth at six months (Group I, n = 18; Group II, n = 19) and 42 percent at 12 months (Group I, n = 16; Group II, n = 15). Chi2 analysis demonstrated no significant differences (P > or = .05) between groups. Seven of 22 restorations in Group I and four of 18 in Group II required repair at 12 months with no statistical difference (chi2 analysis, P > or = .05).

CONCLUSIONS

The interim treatment of eugenol pulpotomy using either restorative material reliably prevented pain for six months. For longer periods, both restorations may require repair.

CLINICAL IMPLICATIONS

This option should preserve the integrity of the arch and extend the use of the tooth while the patient finds the means to finance complete endodontic treatment.

Evaluation of Periapical Lesion Healing by Correction of Gray Values

The purpose of this study was to compare two methods for evaluating periapical healing in humans: the periapical index (PAI) and a gray value correction method. Fifty human teeth with a periapical lesion were endodontically treated. Radiographs, with a special aluminum device, were taken postoperatively, after 3 months and after 6 months. The PAI was recorded at each period of time, and a Kruskall and Wallis test was performed to compare the three groups. After scanning, the size of the lesion and its gray value were recorded. The aluminum device allowed the gray values to be equalized. An analysis of variance followed by a Duncan test was performed to compare the three groups. The teeth that showed no sign of healing according to the PAI were separately analyzed by an analysis of variance and a Duncan test. The PAI (n = 50) showed signs of periapical healing over time (p < 0.01). The analysis of variance, based on gray value evaluation (n = 50), also showed signs of periapical healing over time (p < 0.002). The analysis of variance of teeth with the same PAI over time (n = 15 at 3 months, and n = 5 at 6 months), based on gray value evaluation showed statistically significant differences among the 3 groups (p < 0.02). These results show that the gray level correction method is powerful and may reduce the risks of false negative responses during assessment of treatment results or epidemiological studies.

Apical periodontitis development and bacterial response to endodontic treatment. Experimental root canal infections in monkeys with selected bacterial strains

In six monkeys, 160 root canals were inoculated with a combination of four bacterial strains belonging to species Streptococcus milleri, Peptostreptococcus anaerobius, Prevotella oralis, and Fusobacterium nucleatum. In two other monkeys, 24 root canals were inoculated with a five-strain combination consisting of these strains and a strain of Enterococcus faecalis. All strains were previously isolated from an infected monkey root canal. After 8-12 months, survival of the strains was recorded bacteriologically, and the reaction in the periapical region was radiographed. From 180 of 184 root canals, one or more of the bacterial strains were reisolated. The two facultative strains were more frequently reisolated than the anaerobic strains. Apical periodontitis was registered in the periapical region of more than 96% of root canals with reisolated bacteria but in none of those without reisolated bacteria. Endodontic treatment was carried out in two sessions with an interval of 14 d without interappointment dressings, and the effect was evaluated bacteriologically before and after each treatment. The chemo-mechanical treatment reduced significantly the number of strains and bacterial cells. The facultative bacteria were more resistant to the treatment than the anaerobic bacteria. The five-strain combination had a higher survival rate than the four-strain combination.

Healing of apical periodontitis after endodontic treatment: a comparison between a silicone-based and a zinc oxide-eugenol-based sealer

AIM

To assess the treatment results up to 1 year after endodontic treatment of apical periodontitis using a silicone-based sealer in comparison with Grossman's sealer, and to compare the results at 3 months after treatment with the 12-month follow-up to assess the prognostic value of a 3-month control.

METHODOLOGY

A total of 199 teeth were treated at three centres. The sealer was randomly chosen at the time of filling. Treatment results were evaluated clinically and radiographically 3 and 12 months after root-canal filling. The periapical status was evaluated using the periapical index (PAI).

RESULTS AND CONCLUSIONS

Average PAI scores decreased from 3.43 at start to 2.21 at 12 months for Grossman's sealer and from 3.40 to 2.26 for the silicon-based material. No significant difference between the groups at start or any of the follow ups was seen. The 3-month control was adequate in establishing significant healing in both groups. The improvement of the periapical condition continued at the 12-month examination.