Variations in pulp volume between normotensive and hypertensive individuals on CBCT imaging.

OBJECTIVES: To compare the pulp volume of individuals with altered and normal systemic blood pressure (BP) in order to verify if high BP promotes dimensional modifications in the pulp space. MATERIALS AND METHODS: Cone beam computed tomography scans of 91 patients (49 females and 42 males, mean age 31.7 ± 6.38 years) who had a healthy maxillary canine were selected. Values of arterial BP measured at two dental visits were used to classify the sample as normal BP (< 130 × 80 mmHg) and altered BP (≥ 130 × 80 mmHg); 49 patients had normal BP and 42 had altered BP. One oral radiologist evaluated each patient's pulp and tooth volumes, using semi-automatic segmentation, and the tooth length. Data were submitted to Student's t test and logistic regression, with a significance level of 5% (p < 0.05). RESULTS: Pulp volume (p = 0.0027), pulp volume/tooth volume (p = 0.0013), and pulp volume/tooth length (p = 0.0007) ratios were greater in the altered BP group. Conversely, there was no difference in tooth volume between the groups (p = 0.0697). A logistic regression model (p = 0.0002) using pulp volume and age enabled the development of a formula for predicting altered BP, with 68% accuracy. CONCLUSIONS: Individuals with altered systemic BP have greater pulp volumes than those with normal BP. The formula developed in this study may indicate the presence of altered BP. CLINICAL RELEVANCE: As arterial hypertension is a silent disease that produces no warning signs or symptoms, identification of modifications in the pulp volume in cone beam computed tomography scans may be an adjuvant sign of the diagnosis of this disease.

Evaluation of quality of root canal therapy performed by predoctoral students on endodontic outcome and quality of life of patients.

This study evaluated the technical quality (TQ) of root canal therapy (RCT) performed by predoctoral students and its impact on endodontic outcome (EO) and patients' quality of life (QoL). The TQ of RCT done by predoctoral students was evaluated and follow-up visits were conducted to determine the clinical, radiographic outcome of RCT and patients' QoL. Frequency distribution, multiple regression, independent-samples t test and one-way anova were performed. A total of 226 teeth of 164 patients were clinically and radiographically examined. A satisfactory TQ was observed in 130 (57.5%), successful clinical outcomes in 155 (68.6%), successful radiographical outcomes in 206 (91%) and overall successful EO in 150 teeth (66.4%) with 80% of patients reporting a favourable QoL. A significant positive correlation was noted between EO and QoL (p = 0.002) with no significant correlation in between TQ-RCT and EO (p = 0.07) and TQ-RCT and QoL (p = 0.316). Successful EO had a positive impact on patients' QoL.

Retrospective Evaluation of Periradicular Biopsies: An 18-Year Study.

INTRODUCTION: Radiographic findings in periradicular areas are repeatedly associated with infected root canal systems. Although non-odontogenic lesions in teeth are reported to be low, they often mimic periapical pathoses, and consequently, histopathologic examinations after surgical revisions are nurtured. METHODS: Biopsies submitted to the College of Dentistry between 2003 and 2021 were reviewed. Clinicopathologic characteristics were collected, including age, sex, medical history, location, sensibility tests, and clinic impressions from each specimen. Histopathologic diagnosis and gross description were also part of our database. RESULTS: A total of 72,055 pathology reports were reviewed, of which 10,031 lesions (13.9%) met the criterion of being intraosseous lesions at the periradicular area. Among those 10,031 lesions, 7.94% (n = 796) were of non-endodontic origin, 7153 were documented as non-vital, and 2.36% (n = 169) of these non-vital teeth were diagnosed with a non-endodontic origin. A total of 5707 lesions were obtained from surgeries within the periapical tissues, primarily performed by endodontists (94.02%). Non-endodontic lesions were reported in 1.09% of the cases. Odontogenic keratocyst was the most common non-endodontic diagnosis, followed by nasopalatine duct cyst and benign fibro-osseous lesion, respectively. CONCLUSIONS: Pathologic findings of the periradicular tissues are not always from endodontic origin. The probability of encountering non-endodontic lesions is almost 8%. Even in clinically reported teeth with pulp necrosis, 1%-3% of biopsies were confirmed as non-endodontic lesions.

Emerging therapies for the management of traumatized immature permanent incisors.

Early loss of immature permanent teeth due to pulpal necrosis secondary to trauma can have dire consequences for a child's growth and development. The treatment alternatives include surgical endodontics, traditional calcium hydroxide apexification, and mineral trioxide aggregate (MTA) apexification. These options pose potential complications, including: arrest of root development; weakened dentinal walls; and increased potential for fracture. Revascularization of the dentin-pulp complex is a new approach that involves disinfecting the root canal system followed by tissue repair and regeneration while allowing for continued root development and thickening of the lateral dentinal walls through deposition of new hard tissue. The purpose of this report was to present the revascularization of an immature permanent maxillary central incisor that had evidence of external root resorption. Six months later, internal bleaching was performed to remove cervical discoloration from the triple antibiotic paste. At 18 months, the tooth remained vital and had evidence of continued root development.

Root canal preparation in mandibular premolars with TRUShape and Vortex Blue: A micro-computed tomography study.

A comparison of the preparation ability of two root canal instrumentation systems in oval-shaped canals using micro-computed tomography was undertaken. Thirty extracted, single-rooted, human mandibular premolars with radiographically similar canal morphology were selected, allocated to two groups (N = 15) and prepared with TRUShape or Vortex Blue (VB). Each sample was subjected to three scans (20 µm resolution): pre-preparation and after preparation to sizes #30 and #40. Three-dimensional data sets were evaluated for canal volume, surface area and surface treatment. Matched axial slices in apical, middle and coronal root thirds were evaluated for cross-sectional area, roundness and transportation. Preparation with both instruments increased canal volumes and surface areas similarly and significantly (P < 0.001) with no significant difference between groups. TRUShape significantly enhanced surface treatment at both apical sizes (P < 0.05). Transportation exceeded 100 µm in only eight out of 90 cross sections. Both instruments performed similarly during preparation. TRUShape, however, significantly enhanced surface treatment.

Microbiota of periodontal pockets and root canals in induced experimental periodontal disease in dogs.

AIM: To investigate the relationship between the microbiota of periodontal pockets (PP) and root canals (RC) in dogs submitted to experimental periodontal disease (ExPD). METHODS: ExPD was induced by combining cotton and wire ligatures. After 125 days, microbiological samples were collected from PP and RC. Strains isolated from 19 teeth were submitted to DNA extraction, 16S rRNA gene amplification and gene sequencing. Pearson's χ2 - and Fisher's exact tests and McNemar's test were used when appropriate. RESULTS: The number of species in PP was greater than in RC, with prevalence of obligate anaerobes and Gram-negative bacteria. In the PP predominated Fusobacterium necrophorum, Porphyromonas gingivalis, Prevotella loescheii, Campylobacter gracilis and Veillonella parvula. In the RC samples, 9 had microbial growth, with predominance of the following genera: Staphylococcus, Streptococcus and Neisseria. Eight genera were common to both sites in the same tooth. PP presented a greater number of species than the RC. No significant difference was observed in the species found in PP and RC in the same tooth. CONCLUSION: Microbial composition of the RC could be modulated by the presence of periodontal disease, especially in cases of severe periodontal destruction. RC microbiota was less complex and diverse than the PP.

Clinical efficiency of 2% chlorhexidine gel in reducing intracanal bacteria.

This study evaluated the clinical efficacy of 2% chlorhexidine (CHX) gel on intracanal bacteria reduction during root canal instrumentation. The additional antibacterial effect of an intracanal dressing (Ca[OH](2) mixed with 2% CHX gel) was also assessed. Forty-three patients with apical periodontitis were recruited. Four patients with irreversible pulpitis were included as negative controls. Teeth were instrumented using rotary instruments and 2% CHX gel as the disinfectant. Bacterial samples were taken upon access (S1), after instrumentation (S2), and after 2 weeks of intracanal dressing (S3). Anaerobic culture was performed. Four samples showed no bacteria growth at S1, which were excluded from further analysis. Of the samples cultured positively at S1, 10.3% (4/39) and 8.3% (4/36) sampled bacteria at S2 and S3, respectively. A significant difference in the percentage of positive culture between S1 and S2 (p < 0.001) but not between S2 and S3 (p = 0.692) was found. These results suggest that 2% CHX gel is an effective root canal disinfectant and additional intracanal dressing did not significantly improve the bacteria reduction on the sampled root canals.

Clinical outcome of teeth treated endodontically with a nonstandardized protocol and root filled with resilon.

The purpose of this study was to evaluate the clinical outcomes of root canal treatment in private practice and filled with Resilon. Immediate postoperative radiographs were compared to follow-up radiographs of at least 1 year in 82 randomly selected primary endodontic cases treated according to a nonstandardized protocol but root-filled with Resilon. The Periapical Index (PAI) and the Clinical Impression of Healing (CIH) quantification procedures were used to determine the status and change in the condition of the teeth. The PAI evaluation revealed that 90% of the teeth that were healthy at the initial reading (PAI, 1or 2) maintained the condition at follow-up evaluation. Of those teeth that were unhealthy (PAI, 3-5) at the initial reading, 73.3% were judged healthy (50%) or improved (23.3) at the last evaluation. In contrast, the proportion of healthy or healing with the CIH evaluation was 89.4%. The findings of this study support the contention that regardless of treatment protocol, healing rates for Resilon-filled teeth in private practice were within the range of success rates for studies with uniform treatment techniques mostly in university settings with gutta-percha root filling.

Effect of intracoronal bleaching agents on dentin microhardness.

The purpose of this in vitro study was to compare the effect of intracoronal bleaching agents associated or unassociated with chlorhexidine gel on dentin microhardness. Sixty human maxillary incisor crowns were divided into six groups, and bleaching agents were sealed into the pulp chambers as follows: sodium perborate + water (SPW), sodium perborate + 2% chlorhexidine gel (SP + CHX), sodium perborate + 30% hydrogen peroxide solution (SP + HP), 37% carbamide peroxide gel (CP), 37% carbamide peroxide gel + 2% chlorhexidine gel (CP+CHX), and water (W). After the bleaching procedure, microhardness testing was carried out on the dentin surface at three different levels: inner, middle, and outer dentin. The greatest reduction in microhardness was observed for the SP + HP group. No differences were observed between the SPW and SP + CHX group. The 2% chlorhexidine gel did not adversely affect dentin microhardness when associated with the tested bleaching agents. CHX might be considered as an antimicrobial vehicle during intracoronal bleaching.

Diversity of Enterococcus faecalis Genotypes from Multiple Oral Sites Associated with Endodontic Failure Using Repetitive Sequence-based Polymerase Chain Reaction and Arbitrarily Primed Polymerase Chain Reaction.

INTRODUCTION: The aim of this study was to evaluate the diversity and similarity of Enterococcus faecalis genotype isolates from multiple oral sites using repetitive sequence-based polymerase chain reaction and arbitrarily primed polymerase chain reaction (AP-PCR). METHODS: Forty-two endodontically treated teeth with apical periodontitis were selected. A total of 126 microbial samples were collected from 3 different sites (saliva, pulp chamber, and root canals, all n = 42) during the nonsurgical retreatment procedures. After growth on m-Enterococcus agar, the colonies were isolated, characterized as gram-positive catalase negative cocci, and identified using an API 20 Strep kit (bioMérieux, Marcy-l'Etoile, France). Seventy-four colonies from 10 patients were confirmed as E. faecalis by polymerase chain reaction (16S ribosomal RNA). Repetitive sequence-based polymerase chain reactions using ERIC and AP-PCR using RW3A primers were performed in all 74 colonies. Fingerprints were analyzed and separated into genotypic groups based on the Dice coefficient percentage of similarity (82% or greater) as determined by ERIC reproducibility assays involving E. faecalis controls. RESULTS: Seven different E. faecalis genotypes (GTs) (GT1 = 27%, GT2 = 17.6%, GT3 = 1.3%, GT4 = 18.9%, GT5 = 9.5%, GT6 = 14.9%, and GT7 = 10.8%) were observed in different subjects and oral sites associated with endodontic failure. Remarkably, in 4 of 5 patients, the same GTs present in the infected root canals were also isolated from either the pulp chamber or the saliva samples. In particular, GT6 was detected in all 3 oral sites of patient 37. CONCLUSIONS: E. faecalis GTs isolated from saliva, the pulp chamber, and the root canal were similar using the Rep-PCR and AP-PCR methods. These findings suggest that coronal microleakage is a conceivable cause of endodontic failure.

Effect of intracanal medicament on the sealing ability of root canals filled with Resilon.

The purpose of this in vitro study was to investigate the effects of the use of calcium hydroxide as an intracanal dressing on the sealing ability of a thermoplastic synthetic polymer-based root filling (Resilon). Forty-seven single rooted teeth were decoronated and instrumented to ISO sizes 40. The teeth were randomly divided into three experimental groups of 15 roots each. Group 1 was immediately filled. Group 2 and group 3 had calcium hydroxide paste placed with lentulo-spiral filler. After 7 days, calcium hydroxide was removed from the canals with two different techniques: #15 K-file agitated irrigation with 17% Ethylenediaminetetracitic acid (EDTA) (group 2) or ultrasonically agitated irrigation with 17% EDTA (group 3) for 2 min. All teeth were filled with Resilon points and the resin sealer (Ephiphany root canal sealant) using lateral condensation technique. Two teeth were immediately filled with Resilon master point size 40/.04 without sealer to act as a positive control. A split chamber microbial leakage model using Streptococcus mutans was used and the leakage was evaluated daily for a period of 30 days. Overall, 6 of 44 (14%) of samples filled with Resilon points and the resin sealer had microbial leakage. Three samples in group 1 (21%), two samples in group 2 (13%), and one specimen in group 3 (7%) had bacterial leakage. Using the Fisher's Exact test, there was no statistically significant difference in leakage between the groups with calcium hydroxide dressing and the group without calcium hydroxide (p > 0.05). Under the condition of this study, calcium hydroxide did not adversely affect the seal of the root-canal system filled with Resilon.

Comparison between gutta-percha and resilon removal using two different techniques in endodontic retreatment.

This study compared the remaining filling material and working time when removing gutta-percha/AH 26 and Resilon/Epiphany from root filled extracted teeth. The root fillings were removed using chloroform and two different rotary systems (K3 and Liberator files). The amount of residual filling material on the canal walls was imaged and measured using image analyzer software. The group filled with Resilon/Epiphany and retreated with K3 files demonstrated the least residual filling material on the walls (p < 0.05). There was no statistically significant difference between the gutta-percha/AH26 and Resilon/Epiphany groups when the Liberator files were used (p > 0.05). In the groups filled with Resilon/Epiphany, the filling was removed faster than groups filled with gutta-percha/AH 26 (p < 0.05). K3 rotary system was faster than Liberator to remove both gutta-percha and Resilon (p < 0.05). Resilon/Epiphany was effectively removed with K3 or Liberator rotary files.

An in vitro assessment of prefabricated fiber post systems.

BACKGROUND: The authors conducted a study to characterize the in vitro retention, fracture and light transmission behavior of four different fiber-reinforced resin-based composite root canal posts. METHODS: The authors divided 44 teeth into four groups according to the type of post they would receive: parallel fiberglass posts, double-tapered fiber quartz posts, tapered fiberglass posts and two different types of parallel fiberglass posts. They prepared teeth and cemented posts with dual-cured resin cement. After the specimens aged, the authors conducted pull-out tests. For fracture testing, they loaded posts at 45 degrees in a universal testing machine. They determined load-to-fracture values and relative stiffness. They measured percentage of light transmission by means of a light microscope coupled with a spectrometer. RESULTS: Both tapered posts showed lower retention than did the parallel posts. Scanning electron microscropic analysis indicated that more cement adhered to the surfaces of the parallel fiberglass post than to those of the tapered fiberglass post. All posts demonstrated some plastic behavior, with the double-tapered fiber quartz post being stiffer than the others. CONCLUSION: Parallel fiber-reinforced composite posts showed better retention than did tapered posts when a dual-cured resin-based cement was used. Translucent prefabricated posts have limited light transmission. CLINICAL IMPLICATIONS: Parallel prefabricated fiber posts luted with dual-cured resin-based cement seem to be suitable for clinical application in endodontically treated teeth that require post-and-core restoration, showing good retention and acceptable fracture resistance.

Ideal obturation using synthetic root-filling systems: coronal sealing and fracture resistance.

Several factors can contribute to the clinician's ability to achieve success in endodontic therapy. The importance of the coronal seal to positive endodontic outcomes has been established in numerous studies; fracture strength also has a significant influence on the prognosis of an endodontically treated tooth. This presentation discusses the role of these two factors in contemporary endodontic therapy and demonstrates how the utilization of an adhesively bonded, synthetic root-filling system can support the practitioner's management of nonvital teeth.

Periapical inflammation after coronal microbial inoculation of dog roots filled with gutta-percha or resilon.

A dog model was used to assess and compare in vivo the efficacy of gutta-percha and AH26 sealer versus Resilon with Epiphany primer and sealer [Resilon "Monoblock" System (RMS)] filled roots in preventing apical periodontitis subsequent to coronal inoculation with oral microorganisms. There were 56 vital roots in the premolars of seven adult beagle dogs aseptically instrumented, filled, and temporized. The roots were randomly divided into four experimental groups (Coronal Leakage Model) and one negative control group and filled as follows: group 1-lateral condensation of gutta-percha and AH26 sealer (n=12); group 2-vertical condensation of gutta-percha and AH26 sealer (n=12); group 3-lateral condensation of RMS (n=12); group 4-vertical condensation of RMS (n=10); negative control (n=10)-gutta-percha and AH26 sealer or RMS root fillings using lateral or vertical condensation techniques as in groups 1 to 4. Positive control-57 additional premolar roots were instrumented, infected and not filled (beginning of the Entombment Model experiment). The premolars in groups 1 to 4 were accessed again, inoculated with dental plaque scaled from the dog's teeth, and temporized. This fresh innoculum of microorganisms was repeated on two more occasions at monthly intervals. The teeth in the negative control group were not accessed again and remained undisturbed. On the 14-wk postcoronal inoculation, dogs were euthanized, and jaw blocks prepared for histologic evaluation under a light microcope. Mild inflammation was observed in 82% (18 of 22) of roots filled with gutta-percha and AH26 sealer that was stastistically more than roots filled with RMS (19% or 4 of 21) and roots in the negative control (22% or 2 of 9) (McNemar paired analysis, p < 0.05). The Resilon "Monoblock" System was associated with less apical periodontitis, which may be because of its superior resistance to coronal microleakage.

Investigation of pH at different dentinal sites after placement of calcium hydroxide dressing by two methods.

OBJECTIVE: The dentin pH at different sites following placement of calcium hydroxide paste using 2 different methods was evaluated. STUDY DESIGN: One hundred twenty Extracted teeth were instrumented and randomly divided into 6 different groups. Then they were dressed with calcium hydroxide by 2 different methods using paper points or Lentulo spiral, according to their respective groups, and stored. After the experimental period of time, half of the samples were cut transversally into slices and the other half split longitudinally and rinsed with distilled water. The dentin pH of cervical, middle, and apical thirds was measured from the root canal wall surface and 1 mm away from the root canal lumen in the inner dentin. The results were compared and statistically analyzed. RESULTS: The highest pH values were obtained on the root canal walls when the calcium hydroxide was placed with Lentulo spiral filler (P > .05). There was a significant reduction in pH values in the inner dentin. When the cross sections of teeth were compared at 7 days, the Lentulo group was statistically different only in the apical third. CONCLUSIONS: Placement of the calcium hydroxide paste with a Lentulo spiral with subsequent compaction with the blunt end of a sterile paper point obtained a higher pH value on the canal walls and in the inner dentin than paper points only.

Accuracy of digital periapical radiography and cone-beam computed tomography in detecting external root resorption.

PURPOSE: The purpose of this study was to evaluate and compare the efficacy of cone-beam computed tomography (CBCT) and digital intraoral radiography in diagnosing simulated small external root resorption cavities. MATERIALS AND METHODS: Cavities were drilled in 159 roots using a small spherical bur at different root levels and on all surfaces. The teeth were imaged both with intraoral digital radiography using image plates and with CBCT. Two sets of intraoral images were acquired per tooth: orthogonal (PA) which was the conventional periapical radiograph and mesioangulated (SET). Four readers were asked to rate their confidence level in detecting and locating the lesions. Receiver operating characteristic (ROC) analysis was performed to assess the accuracy of each modality in detecting the presence of lesions, the affected surface, and the affected level. Analysis of variation was used to compare the results and kappa analysis was used to evaluate interobserver agreement. RESULTS: A significant difference in the area under the ROC curves was found among the three modalities (P=0.0002), with CBCT (0.81) having a significantly higher value than PA (0.71) or SET (0.71). PA was slightly more accurate than SET, but the difference was not statistically significant. CBCT was also superior in locating the affected surface and level. CONCLUSION: CBCT has already proven its superiority in detecting multiple dental conditions, and this study shows it to likewise be superior in detecting and locating incipient external root resorption.

Fracture resistance of roots endodontically treated with a new resin filling material.

BACKGROUND: The authors evaluated the fracture resistance of endodontically treated teeth filled with either gutta-percha or a new resin-based obturation material. METHODS: The authors prepared and randomly divided 80 single-canal extracted teeth into five groups: lateral and vertical condensation with gutta-percha, lateral and vertical condensation with the new resin-based obturation material, and a control group with no filling material. The specimens were stored in 100 percent humidity for two weeks, mounted in polyester resin and loaded to failure. RESULTS: The authors found statistically significant differences among the experimental groups (P < .05). The groups with the new material displayed higher mean fracture loads and the gutta-percha groups lower mean fracture load values than the control unfilled group. However, the differences were not significant. The groups with the new material displayed significantly higher mean fracture loads than gutta-percha groups independent of the filling technique used. CONCLUSIONS: Filling the canals with the new resin-based obturation material increased the in vitro resistance to fracture of endodontically treated single-canal extracted teeth when compared with standard gutta-percha techniques. CLINICAL IMPLICATIONS; If other properties of the new resin-based obturation material compare favorably with those of gutta-percha for filling the root canal, it should be considered as a replacement for gutta-percha, as the results of this study indicate that it could provide enhanced resistance to tooth fracture.

Effect of dentin conditioning with intracanal medicaments on survival of stem cells of apical papilla.

INTRODUCTION: Regenerative endodontics is a valuable treatment modality for immature teeth with pulpal necrosis. A common feature in regenerative cases is the use of intracanal medicaments. Although these medicaments are chosen because of their antibacterial properties, their enduring effect on dentin (conditioning) and the subsequent impact on stem cell survival has never been evaluated. In this study, we hypothesized that triple antibiotic paste (TAP), double antibiotic paste (DAP), or Ca(OH)2 has an indirect adverse effect on the survival of stem cells of apical papilla (SCAP) by dentin conditioning. METHODS: Human dentin disks were created with a standardized root canal diameter of 3.2 mm. The disks were then exposed to either TAP or DAP (at concentrations of 1 mg/mL or 1000 mg/mL), Ca(OH)2 (Ultracal), or Hank's balanced salt solution for 7 or 28 days. Next, the medicaments were removed with copious irrigation, followed by placement of SCAP in a Matrigel scaffold in the lumen of the disks. The bioengineered constructs were cultured for 7 days, followed by determination of cellular viability by using the CellTiter-Glo luminescence assay. Data were analyzed using 1-way analysis of variance with Bonferroni post hoc test. RESULTS: Exposure of dentin to TAP or DAP at 1000 mg/mL resulted in no viable SCAP, whereas the use of these medicaments at 1 mg/mL had no adverse effect on cell viability. In contrast, Ca(OH)2 treatment significantly increased SCAP survival and proliferation when compared with the control group. CONCLUSIONS: Dentin conditioning with TAP and DAP at commonly used clinical concentration (approximately 1000 mg/mL) alters dentin in such a way as to prevent SCAP survival. This lethal indirect effect of both TAP and DAP can be largely avoided if these medicaments are used at the 1 mg/mL concentration. Conversely, dentin conditioning with Ca(OH)2 promotes SCAP survival and proliferation.

Paradigm lost: a perspective on the design and interpretation of regenerative endodontic research.

Regenerative endodontic procedures are rapidly gaining the attention of clinicians and investigators alike. However, it is often challenging to understand various regenerative studies and to interpret their results. The present review addresses this problem by focusing on recent strategies for developing standardized clinical protocols, understanding the full spectrum of clinical and translational research and its relationship to selection of proper outcome measures, as well as reviewing the fundamental role of paradigms in designing and interpreting regenerative studies.