An In Vitro Evaluation of Fracture Resistance of Endodontically Treated Maxillary Central Incisor Restored with Custom-Made Cast Post and Core with Uniform and Nonuniform Core Ferrule Heights.

AIM: The aim of this study was to evaluate in vitro fracture resistance of endodontically treated teeth restored with custom-made cast post and core having uniform and nonuniform core ferrule heights. MATERIALS AND METHODS: Thirty-five freshly extracted human maxillary central incisors were included in this study. All teeth were subjected to standard root canal treatment. The teeth were randomly divided into five groups-Group 1: uniform ferrule (2 mm buccal, lingual, and proximal), Group 2: uniform ferrule (3 mm buccal, lingual, and proximal), Group 3: nonuniform ferrule (2 mm buccal, 3 mm lingual), Group 4: nonuniform ferrule (2 mm buccal, 4 mm lingual), and Group 5: no ferrule. The teeth were sectioned horizontally 4 mm above cementoenamel junction and post space preparation was performed maintaining 4 mm of apical gutta-percha. Ferrule was prepared according to dimension designated for each group. Custom-made cast post and core were fabricated and luted using zinc phosphate cement. Testing was conducted using universal testing machine with application of static load (Newton), and failure load was recorded. Data were analyzed by one-way analysis of variance and Tukey test. The mode of fracture was noted by visual inspection for all specimens. RESULT: Significant differences (P < 0.001) were found among mean fracture forces of test groups. Group 1: 1181.66 ± 68.29, Group 2: 1455.58 ± 173.11, Group 3: 1019.00 ± 52.55, Group 4: 971.58 ± 66.52, and Group 5: 888.00 ± 60.56. The presence of nonuniform ferrule height resulted in a significant decrease (P < 0.0001) in mean fracture strength compared to uniform 2- and 3-mm core ferrule height. CONCLUSION: The central incisors restored with cast post and core and crowns with 3-mm uniform core ferrule were more fracture resistant compared to central incisors with nonuniform core ferrule height. Both the uniform and nonuniform core ferrule groups were more fracture resistant than the group that lacked ferrule.

Disinfection of dentinal tubules with 2% chlorhexidine, 2% metronidazole, bioactive glass when compared with calcium hydroxide as intracanal medicaments.

Thorough disinfection of the root canal system is essential for the success of root canal therapy. This requires the use of an intra-canal medicament. Enterococcus faecalis is the most frequently found species in persistent/secondary intracanal infection associated endodontic treatment failure. This study evaluates the disinfection of dentinal tubules using 2% chlorhexidine gel, 2% metronidazole gel, bioactive glass (S53P4) in comparison with calcium hydroxide. The antibacterial efficacy of the four medicaments against Enterococcus faecalis was assessed in vitro using extracted premolar teeth at the depths of 200 microm and 400 microm. The overall percentage inhibition of bacterial growth (at 200 microm and 400 microm depth) was 100% with 2% chlorhexidine gel. The inhibition of growth was moderate with 2% metronidazole gel (86.5%), followed by bioactive glass (62.8%) and calcium hydroxide (58.5%). It can be concluded from the present study that 2% chlorhexidine gel alone was most effective against E. faecalis when compared to other medicaments tested.

Photoactivated disinfection (PAD) of dental root canal system - An ex-vivo study.

AIM: To investigate the efficacy of photo activated disinfection (PAD) in reducing colony-forming unit (CFU) counts of Enterococcus faecalis (E. faecalis) in infected dental root canals. The study compared the efficacy of PAD with conventional endodontic treatment (CET) and also a combination of CET along with PAD. MATERIAL AND METHODS: 53 maxillary incisors were taken for the study. Teeth were divided into 3 groups, CET (Group I) (n = 11), PAD (Group II) (n = 21), and a combination of CET and PAD (Group III) which consisted of (n = 21) samples, Group II and Group III were further divided into 2 subgroups, Group IIa, IIb and Group IIIa, IIIb. Strains of E. faecalis were inoculated in all the root canals. CET group samples were treated by chemo-mechanical preparation (CMP) alone, PAD samples were treated with laser alone at 2 different exposure time (4 min and 2 min). In the combination treatment, samples were treated initially by CET and then by PAD for a time period of 4 min and 2 min. Contents of the root canal were aspirated, diluted and plated in Tryptone Soya Broth (TSB) and plates were incubated for 24 h to observe the bacterial regrowth. RESULTS: Showed PAD used along with CMP reduced the bacterial load of E. faecalis by 99.5% at 4 min and 98.89% at 2 min. CONCLUSION: PAD may be an adjunctive procedure to kill residual bacteria in the dental root canal systems after standard endodontic root canal preparation.

Role of casein phosphopeptide amorphous calcium phosphate in remineralization of white spot lesions and inhibition of Streptococcus mutans?

INTRODUCTION: To promote the remineralization by ionic exchange mechanism instead of invasive techniques many remineralizing agents can be used. OBJECTIVE: To evaluate the remineralization effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) on white spot lesions (WSLs) and its inhibitory effect on Streptococcus mutans colonization. MATERIALS AND METHODS: The study group consisted of 60 subjects exhibiting at least 1-WSL. Subjects were randomly divided into 2 groups: A test group using CPP-ACP cream (GC-Tooth Mousse, Leuven, Belgium) and a control group using only fluoride containing toothpaste for a period of 3-month. Baseline WSLs were scored using DIAGNOdent device (KaVo Germany) and the saliva samples were collected to measure S. mutans counts. After the 3-month period the WSLs were again recorded and the saliva collection was repeated. RESULT: DIAGNOdent measurements were increased by time (P = 0.002) in the control group and no statistically significant difference (P = 0.217) was found in the test group by the 3-month period. In both groups, the mutans counts were decreased in the 3-month experimental period. CONCLUSION: These clinical and laboratory results suggested that CPP-ACP containing cream had a slight remineralization effect on the WSL in the 3-month evaluation period however, longer observation is recommended to confirm whether the greater change in WSLs is maintained.

Depth of penetration of four resin sealers into radicular dentinal tubules: a confocal microscopic study.

BACKGROUND: The aim of this in vitro study was to evaluate the depth of penetration of 4 different endodontic resin sealers into the radicular dentinal tubules with the aid of confocal microscopy. METHODS: Eighty single-rooted teeth were instrumented and divided into 4 groups composed of 20 teeth each. The samples were obturated with AH Plus, RealSeal, EndoRez, and RoekoSeal resin sealers, respectively. The core material in all the groups was Resilon. The teeth were sectioned at the coronal, middle, and apical thirds and viewed under confocal microscope to determine the depth of penetration of the sealer into the dentinal tubules. RESULTS: The results showed that the maximum penetration was exhibited by RealSeal resin sealer, followed by AH Plus, RoekoSeal, and EndoRez. The coronal third showed the maximum penetration, followed by middle third and least at the apical third. CONCLUSION: Under the parameter of this study, RealSeal resin sealer exhibited the maximum penetration.

Independent and confluent middle mesial root canals in mandibular first molars: a report of four cases.

Mandibular molars demonstrate considerable variations with respect to number of roots and root canals. The possibility of additional root canals should be considered even in teeth with a low frequency of abnormal root canal anatomy. This paper discusses the endodontic management of the rare anatomical complexity middle mesial canals in mandibular first molar and also serves to remind the clinicians that such anatomical variations should be taken into account during the endodontic treatment of the mandibular molars.

The effect of two bleaching agents on the phosphate concentration of the enamel evaluated by Raman spectroscopy: An ex vivo study.

AIM: The aim of this ex vivo study was to evaluate the effect of in-office bleaching agents,-35% and 38% hydrogen peroxide containing bleaching agents, on the phosphate concentration of the enamel evaluated by Raman spectroscopy. MATERIALS AND METHODS: Forty noncarious, craze-free human maxillary incisors, extracted for periodontal reasons, were used in this study. Baseline Raman spectra from each specimen were obtained before the application of the bleaching agent to assess the phosphate content present in the teeth. The teeth were divided into two groups: Group A - bleached with pola office bleach (35% hydrogen peroxide, potassium nitrate) (light activated). Group B - bleached with opalescence Xtra bleach (38% hydrogen peroxide potassium nitrate and fluoride) (chemical activated). After the bleaching procedure, the treated specimens were taken to obtain Raman spectra to assess the phosphate loss after bleaching treatment. RESULTS: The results showed that the chemically activated bleaching agent showed less phosphate loss when compared with the light activated bleaching agent. CONCLUSION: Within the limitations of this study, it can be concluded that the chemically activated bleaching agent showed minimal phosphate loss when compared to light activated bleaching agent. The chemically activated bleaching agent was better than the light activated bleaching agent when values were evaluated statistically.

A comparative evaluation on the cleaning and shaping ability of three nickel titanium rotary instruments using computerized tomography - An ex vivo study.

INTRODUCTION: Successful root canal treatment depends primarily on the removal of micro-organisms through chemo-mechanical instrumentation of the root canal system. This encompasses shaping by mechanical removal of the dentine and cleaning by chemical disinfection of microorganisms and dissolution of organic tissues from the root canal. While root canal shaping can be predictably and efficiently attained with advanced instrumentation technology, effective cleaning of the entire root canal system remains a challenge. Rotary nickel titanium instruments are known for their efficient preparation of root canal. This is mainly because of the super elasticity of the nickel titanium alloy which gives an increased flexibility and allows the instrument to efficiently follow the original path of root canal. The purpose of this study is to compare the cleaning efficiency and shaping ability of M two, K3, Race ni-ti rotary instruments during the preparation of curved canals in extracted molars. MATERIALS AND METHODS: Thirty teeth with 18 mm as their working length were selected and divided into three groups of 10 teeth each Angle of curvature, Radius of curvature, was determined using computerized tomography. A Pre and Post-operative measurement of canal width and volume was recorded and compared using CT. The teeth was then sectioned into two halves and subjected to scanning electron microscope. Images were taken at the level of apical third, middle third and coronal third for debris and smear layer. Scoring was done separately for both debris and smear layer. RESULTS: Results were tabulated and statistically analyzed to evaluate the shaping ability and cleaning efficiency. Instruments were examined for any deformation or fracture during canal preparation. CONCLUSION: M two showed greater enlargements in all the three levels, when compared its width and volume, with other two instruments. K3 was better than Race when compared among them. In the scanning electron microscope study for debris and smear layer M Two performed better followed by K3 and Race.

Prevalence of radix entomolaris in mandibular permanent first molars: a study in a South Indian population.

OBJECTIVE: Anatomical racial variations are an acknowledged characteristic in permanent molars. Generally, mandibular first molars have 2 roots; however, the presence of a third root, radix entomolaris (RE), is a major anatomic variant among many population groups. This study evaluated the prevalence of permanent mandibular first molars featuring a distolingual root in a South Indian population. STUDY DESIGN: Five hundred patients of South Indian origin possessing bilateral mandibular first molars were selected. The radiographs of these patients were evaluated under optimal conditions. A total of 1000 mandibular first molars were screened and the incidence of 3-rooted mandibular first molars and the correlation between left and right side occurrence and between either gender was recorded. RESULTS: The prevalence of 3-rooted mandibular first molars was 18.6% of the patients examined and 13.3% of the teeth examined. There was no statistically significant difference between genders or side of occurrence (P > .05). The bilateral incidence of a symmetric distribution was 43.01%. CONCLUSIONS: RE is considered an Asiatic trait. The occurrence of this macrostructure in the South Indian population was 13.3%, which was lower than that of other patients of Mongoloid origin. The clinician must thoroughly examine the radiograph before initiation of endodontic therapy.

Anesthetic efficacy of four percent articaine for pulpal anesthesia by using inferior alveolar nerve block and buccal infiltration techniques in patients with irreversible pulpitis: a prospective randomized double-blind clinical trial.

INTRODUCTION: The study was designed as a randomized double-blind trial to evaluate the anesthetic efficacy of 4% articaine with 1:100,000 epinephrine in inferior alveolar nerve block (IANB) and infiltration anesthetic techniques to anesthetize mandibular molars with irreversible pulpitis. METHODS: The study was composed of 2 test arms and 1 control arm. Subjects in the test arms received either a standard IANB or a buccal infiltration (B Infil) of 4% articaine with 1:100,000 epinephrine, whereas the subjects in the control arm received a standard IANB of 2% lidocaine with 1:100,000 epinephrine. Subject's self-reported pain response was recorded on Heft Parker Visual Analogue Scale after local anesthetic administration during access preparation and pulp extirpation. RESULTS: For statistical analysis Pearson χ(2), Student's paired t test, 1-way analysis of variance, and Friedman tests showed no significant difference in success rates among the 3 arms of the trial. CONCLUSIONS: Although B Infil and IANB of 4% articaine were equally effective, B Infil can be considered a viable alterative in IANB for pulpal anesthesia in mandibular molars with irreversible pulpitis.

Mandibular first premolar with two roots and three canals.

This case report presents a relatively uncommon clinical case of a mandibular premolar with two roots and three canals. The possibility of additional root canals should be considered even in teeth with a low frequency of abnormal root canal anatomy. Sound knowledge of root canal anatomy, appropriate assessment of the pulp chamber floor, critical interpretation of radiographs and high-magnification examinations are highly desirable to achieve the best possible outcome in complicated root canal therapy.

Spiral CT diagnosis and endodontic management of an anatomically variant palatal root with two canals in a maxillary first molar.

This case report presents the endodontic management of an anatomically variant palatal root with 2 canals (Vertucci type II) in a maxillary first molar, which was confirmed with the help of spiral computed tomography (SCT). This serves to remind clinicians that such anatomic variations should be taken into account during the endodontic treatment of maxillary molars and highlights the invaluable aid of the SCT in accurate diagnosis and in negotiating the complex morphologic variations in root canals, thus enabling successful endodontic management.

Antifungal efficacy of 5.25% sodium hypochlorite, 2% chlorhexidine gluconate, and 17% EDTA with and without an antifungal agent.

INTRODUCTION: The aim of this in vitro study was to evaluate the efficacy of 5.25% sodium hypochlorite (NaOCl), 2% chlorhexidine gluconate (CHX), and 17% EDTA as a final irrigant with and without the inclusion of an antifungal agent (1% clotrimazole) on Candida albicans. METHODS: Sixty-five single-rooted instrumented and inoculated with a suspension of C. albicans. The experimental specimens were divided into two groups. The irrigant group was divided into three subgroups and irrigated with 5.25% NaOCl, 2% CHX, and 17% EDTA, respectively. The irrigant with antifungal group was divided into three subgroups and irrigated with 5.25% NaOCl, 2% CHX, and 17% EDTA respectively followed by 1% clotrimazole. Aliquots from the experimental teeth were plated on 4% Sabouraud agar (Tital Biotech, Delhi, India), and the colony-forming units (CFUs) were evaluated under light microscopy (400x). RESULTS: NaOCl, 5.25%, exhibited superior antifungal efficacy compared with 2% CHX and 17% EDTA (p < 0.001). On inclusion of 1% clotrimazole, there was a significant decrease in the CFU (p < 0.001); 5.25% NaOCl and 2% CHX with clotrimazole showed significantly greater antifungal properties than 17% EDTA with clotrimazole (p < 0.001). CONCLUSION: One percent of clotrimazole proved to be effective against C. albicans when used along with root canal irrigants as a final rinse.

Effect of 10% sodium ascorbate on the calcium: Phosphorus ratio of enamel bleached with 35% hydrogen peroxide: an in vitro quantitative energy-dispersive X-ray analysis.

OBJECTIVES: The study assessed quantitatively the calcium and phosphorous loss from the enamel surface following bleaching with 35% hydrogen peroxide and reversal with 10% sodium ascorbate using energy-dispersive X-ray analysis (EDAX). MATERIALS AND METHODS: Eight non-carious, freshly extracted human permanent maxillary central incisors without any visible defects were used. Each specimen was bleached with 35% hydrogen peroxide activated by light and reversed with sodium ascorbate antioxidant gel. The calcium and phosphorous content in weight percent of sound, bleached and reversed enamel was acquired using EDAX. The Ca/P ratio was calculated from the obtained data. One-way ANOVA followed by Post Hoc Tukey test was used for comparing the Ca/P ratio of sound, bleached and reversed enamel. RESULTS: All the samples subjected to bleaching using 35% hydrogen peroxide showed a statistically significant decrease in the Ca/P ratio as compared with samples in which no bleaching procedure was performed (P-value < 0.01). The striking finding was that there was a significant increase in the Ca/P ratio on application of sodium ascorbate antioxidant gel when compared with the bleached enamel (P-value < 0.01). CONCLUSION: The authors concluded that 35% hydrogen peroxide causes a significant decrease in the Ca/P ratio. This decrease in the Ca/P ratio can be restored by the application of 10% sodium ascorbate antioxidant gel.

A comparative study on the shaping ability of k3, profile and protaper instruments in simulated curved root canals.

INTRODUCTION: The objective of this study was to compare the shaping ability of three rotary filing systems; constant taper K3 instruments, constant taper ProFile instruments and progressive taper ProTaper rotary instruments in clear resin blocks with simulated curved root canals. MATERIALS AND METHODS: Forty five resin blocks were divided into three groups. Group A preparation was conducted with K3, Group B with ProFile and Group C with ProTaper instruments. Pre and post instrumentation images were superimposed and assessment of the canal shape was completed with a computer image analysis program at 14 levels of the root canal system. RESULTS: Group A inner and outer curvature pre and post instrumentation values were significantly different (P<0.05) at levels 3; at level 13 only the outer curvature and levels 6, 7, 8 the inner curvature had significantly different values between pre and post instrumentation. Group C had significant P values (P<0.05) at levels 2, 3, 4, 12, 13 in the outer curvature and at levels 6, 7, 8 of the inner curvature. CONCLUSION: Overall, all three rotary instruments maintained root canal curvatures well. ProTaper instruments significantly removed more resin material from outer canal curvature in the apical third when compared to the other two groups.

Endodontic management of a mandibular first molar with three distal canals confirmed with the aid of spiral computerized tomography: a case report.

Identification and treatment of extra canals is the cornerstone to successful endodontic practice. Over the years, many diagnostic aids have evolved to facilitate the clinician in detection of hidden canals and to familiarize with the internal radicular anatomy. This case report highlights the rare incidence of 3 canals in the distal root of a permanent mandibular first molar. A spiral computerized tomography scan was used as a noninvasive diagnostic tool to confirm the diagnosis.

Maxillary first molar with aberrant canal configuration: a report of 3 cases.

The prognosis for endodontic treatment in teeth exhibiting morphological aberrations is unfavorable if the clinician fails to recognize extra root canals. This report demonstrates 3 clinical cases of maxillary first molars that presented 2 canals in the palatal root merging at the apical third (Vertucci's type II canal morphology), a pattern that is rare and seldom encountered.