Comparative analysis of the effect of autoclaving and 10% formalin storage on extracted teeth: A microleakage evaluation

Shear Bond Strength of Metal and Ceramic Brackets Depending on Etching Protocol in Direct Bonding Technique

Successful orthodontic therapy, apart from a proper treatment plan, depends on optimal bracket-enamel adhesion. Among numerous factors affecting adhesion, the type of bracket and preparation of the tooth's surface are crucial. The aim of this study was to compare the shear bond strength (SBS) of metal and ceramic brackets to the enamel's surface using direct bonding. Forty extracted human premolars were divided into four groups according to the etching method (etch-and-rinse and self-etch) and bracket type. The SBS and adhesive remnant index (ARI) were determined. The ceramic brackets achieved the highest SBS values both in the self-etch (SE) and etch-and-rinse (ER) protocols. Higher SBS values for ceramic and metallic brackets were found in the ER protocol. In all tested groups, the achieved SBS value was satisfactory to withstand orthodontic and occlusal forces. There was no significant difference in the ARI score between study groups (p = 0.71). The fracture occurred between the bracket base and adhesive material in both types of brackets, which decreased the risk of enamel damage during debonding.

Effect of strontium-doped bioactive glass-ceramic containing toothpaste on prevention of artificial dentine caries formation: an in vitro study

Backgroud

Root caries in aging population was prevalent worldwide. Due to the absence of enamel and specific structure of dentine, bacteria are able to penetrate further into dentine at an earlier stage of lesion development. The aim of this study was to investigate the effect of adding of a strontium-doped bioactive glass-ceramic (HX-BGC) to a fluoride-free toothpaste on prevention of formation of artificial dentine caries.

Methods

Thirty-six human tooth specimens were allocated to three groups (n = 12 per group). Group 1 treated with slurry containing a fluoride-free toothpaste and 5% HX-BGC, Group 2 was treated with fluoride-free toothpaste slurry, and Group 3 received deionized water as a negative control. The specimens were subjected to four cycles (15 h demineralization and 8 h remineralization for one cycle) of biochemical cycling. A mixed suspension of five bacteria species (Streptococcus mutans, Streptococcus sobrinus, Lactobacillus acidophilus, Lactobacillus rhamnosus, and Actinomyces naeslundii) were prepared in brain heart infusion broth with 5% sucrose and used as acidic challenge in biochemical cycling. Subsequently, surface morphology of the dentine lesion was assessed by scanning electron microscopy, while the lesion depths and mineral loss were assessed by micro-computed tomography.

Results

The mean lesion depths in dentine in Groups 1 to 3 were 87.79 ± 16.99 μm, 101.06 ± 10.04 μm and 113.60 ± 16.36 μm, respectively (p = 0.002). The mean amounts of mineral loss in Groups 1 to 3 were 0.82 ± 0.10 g/cm³, 0.89 ± 0.09 g/cm³ and 0.96 ± 0.11 g/cm³, respectively (p = 0.016). No obvious differences in the surface morphology were seen among the groups.

Conclusion

Addition of strontium-doped bioactive glass-ceramic to fluoride-free toothpaste has potential to reduce formation of dentine lesions.

Interfacial Biomaterial-Dentin Bacterial Biofilm Proliferation and Viability Is Affected by the Material, Aging Media and Period

Biomaterial−dentin interfaces undergo degradation over time, allowing salivary, tissue fluid, and bacterial movement between the root filling or restoration and dentin. This study aims to investigate the effect of aging in simulated human salivary/bacterial/blood esterases (SHSE) on proliferation and viability of Enterococcus faecalis biofilm within the dentin interface with four materials used to fill/restore the endodontic space. Root canals of human anterior teeth were prepared and filled with gutta-percha and one of the following: self-cured resin composite (BisfilTM 2B, Bisco, Schaumburg, IL, USA) with either self-etch (SE) (EasyBond) or total-etch (TE) (ScotchbondTM, 3M, Saint Paul, MN, USA) methacrylate-based adhesives, epoxy-resin sealer (AH Plus®, Dentsply Sirona, York, PA, USA), or bioceramic sealer (EndoSequence® BC Sealer™, Brasseler USA, Savannah, GA, USA). Specimens were aged in SHSE or phosphate-buffered saline (PBS) for up to 360 days, followed by cultivation of steady-state E. faecalis biofilm. Depth and viability of interfacial bacterial biofilm proliferation were assessed by confocal laser scanning microscopy and live/dead staining. Data were analyzed using three-way ANOVA and Scheffe’s post hoc analyses. Initial depths of biofilm proliferation were similar among material groups (p > 0.05). All groups showed significantly deeper biofilm proliferation with increased aging period (p < 0.05). SHSE aging increased interfacial biofilm depth for TE, SE and BC (p < 0.05) but not AH. For unaged interfaces, BC exhibited the lowest ratio of live bacteria, followed by AH, TE, and SE (p < 0.05). Interfacial bacterial biofilm proliferation and viability were dependent on the biomaterial, aging media, and period.

Influence of Diode Laser for the Treatment of Dentin Hypersensitivity on Microleakage of Cervical Restorations

Noncarious cervical lesions (NCCLs) are a common clinical finding often linked with dentin hypersensitivity (DH). Aim. The aim of the study was to evaluate the influence of diode laser for the treatment of DH on microleakage of subsequent NCCL restorations. Materials and Methods. Forty-eight extracted human premolars were collected. All teeth received standardized cervical preparation on both the buccal and palatal surfaces and were randomly divided into three groups (n = 16) according to the restorative material used: nanohybrid composite resin (CR), resin-modified glass ionomer (RMGI), and conventional glass ionomer (GIC). The prepared cavities on the palatal surfaces were treated by diode laser using SIROlaser Blue (Sirona Dental Systems, Bensheim, Germany) prior to restoration, while preparations on the buccal surfaces were directly restored. After thermocycling, the teeth were immersed in methylene blue dye for microleakage evaluation under 40x magnification at both occlusal and cervical margins. The Kruskal-Wallis test followed by the Bonferroni tests was conducted to determine inter- and intragroup differences (P < 0.05). Results. All restorative materials tested showed some degree of microleakage with no statistically significantly different scores with or without the use of laser desensitization prior to restorative treatment. Group CR showed the least microleakage, followed by group RMGI, while group GIC showed the highest. Cervical margins showed greater microleakage than the occlusal margins where the difference was statistically significant in the RMGI group without laser pretreatment (P = 0.006) and in both groups CR (P = 0.02) and RMGI (P = 0.006) with the laser pretreatment. Conclusion. Application of diode laser for the treatment of DH prior to the restoration of teeth with NCCL did not affect the microleakage of all the restorative materials tested. All the materials showed some degree of microleakage, which was higher in gingival margins compared to occlusal margins. The resin composite shows the least microleakage among all the tested materials.

Resistance to fracture of intraradicular posts made of biological materials

Background

The aim was to analyze the fracture resistance of human teeth treated endodontically and restored with posts made of bovine dentin, human dentin, or glass fiber, and to evaluate the fracture pattern.

Methods

Cylindrical posts of 1.5 mm in diameter cemented to the roots of human maxillary canines presented a length of 15 mm, cervical diameter of 5–5.5 mm in the mesiodistal direction, and 7–7.5 mm in the vestibule-palatal direction. The groups studied were: Group I—10 glass fiber posts; Group II—10 human dentin posts; Group III—10 bovine dentin posts (self-adhesive resin cement); and Group IV—10 bovine dentin posts (resin-modified glass-ionomer cements). The coronal part of tooth was restored with a standardized core build-up using composite. All of the groups were submitted to a compression force test and the resistance to fracture was verified using a universal testing machine. The fracture pattern was likewise evaluated.

Results

The values of resistance to fracture were: 723.3N in group I, 561.5N in group II, 556.6N in group III, and, 613.27N in group IV. However, no statistically significant difference was observed among the groups. The fractures in groups I and II were most commonly found in the middle/apical third and were considered irreparable. For restored teeth in group III, half of the fractures appeared in the cervical third and were reparable. In group IV, all of the fractures were reparable, with the majority in the cervical thirds.

Conclusion

Bovine dentin can be used as intraradicular post to substitute human dentin and glass fiber posts. The greater the malleability of the post, the greater the chances of survival of the teeth when subjected to fracture testing.

Apical Debris Extrusion with Conventional Rotary and Reciprocating Instruments

Introduction

The aim of the present study was to compare the amount of apical debris extrusion after preparation using hand files, reciprocating files, and full rotary nickel-titanium systems.

Methods and Materials

One hundred extracted human mandibular molars with two separated canals in mesial root were divided into five groups and prepared using reciprocating systems (Reciproc file and Safesider endodontic reamers file), full rotary systems (Mtwo and Neoniti A1 files) and hand instrumentation systems. Endodontic access was prepared and a #15 K-file was passed beyond the apex of the mesiobuccal canal by 1 mm to ensure the canal patency. All mesiobuccal canals were prepared 1 mm shorter than the anatomic apex. In each case, extruded debris was collected in an Eppendorf tube and weighed after desiccation. The mean weight of extruded material was calculated in each group. The analysis was carried out using the Kruskal-Wallis test followed by two tailed and Mann-Whitney U test at a significance level of 0.05. The Bonferroni correction was also applied to correct multiple comparisons.

Results

There was a statistically significant difference between the reciprocal and other techniques in debris extrusion (P<0.05). The order of groups ranked in terms of debris extrusion from the lowest to highest was as follows: 1) Hand instrumentation group (with crown down technique), 2) Mtwo group, 3) Neoniti A1 group, 4) Safesider endodontic reamer group, and 5) Reciproc group.

Conclusion

Based on this in vitro study, all systems have some apical debris extrusion; however, using the hand instrumentation system resulted in extrusion of significantly less debris compared to the Reciproc group. It seems that hand and rotary instrumentation systems are better than reciprocating instrumentation systems in terms of the amount of debris extrusion.

Awareness, Attitude and Practice Regarding Disinfection and Handling of Extracted Teeth among the Students in a Dental College in India

Objective:

The main objective of this study is to assess about the awareness, attitude, and practice regarding disinfection and handling of extracted teeth among the students of a dental college in Odisha, India.

Materials and Methods:

The survey was done with a self-designed questionnaire distributed among the students of a dental college in Odisha, India. Data analysis was done using the Statistical Package for the Social Sciences Software (SPSS for Windows, Version 16.0., Released 2007, Chicago, SPSS Inc.) and the results obtained.

Results:

Of the many methods available, the safest and practical methods to sterilize and disinfect the extracted human teeth could be autoclaving, submersion in 10% formalin and 5.25% sodium hypochlorite solutions. In addition, it was found that there is a significant need to educate the potential handlers of such extracted teeth about the latest statuary protocol and guidelines.

Conclusion:

Most of the participants in the study were aware of the established safety protocols regarding how to handle the pathogenic specimens and were putting in practice those standardized guidelines. But still another good number of handlers need to change their casual attitude while following the safety guidelines so as to protect themselves, others and the environment from the pathogenic clinical specimens.

Evaluation of the effects of the solution used for electrochemical dissolution of nickel-titanium endodontic files on dentine structure, microhardness and cell viability

AIM

To evaluate the effects of the [NaF 12 g L^-1  + NaCl 1 g L^-1 ] solution used in the electrochemical dissolution process of fractured endodontic files, as well as its NiTi-containing product, on dentine hardness, topography and human fibroblast viability.

METHODOLOGY

Sixty single-rooted human teeth were evaluated for dentine microhardness using the Vickers hardness test and the area and number of dentinal tubules by scanning electron microscopy. The samples were divided according to the dentine surface treatment: distilled water; 17% EDTA; [NaF 12 g L^-1  + NaCl 1 g L^-1 ]; and 17% EDTA + [NaF 12 g L^-1  + NaCl 1 g L^-1 ]. Thirty-six single-rooted human teeth were divided according to the irrigation protocol: Dulbecco's Modified Eagle's Medium + 10% foetal bovine serum; 5.25% NaOCl; [NaF 12 g L^-1  + NaCl 1 g L^-1 ]; and [NaF 12 g L^-1  + NaCl 1 g L^-1  + NiTi]. The extracts in contact with the apical foramen were used in the MTT assay to evaluate human fibroblast viability, with dilutions of 100%, 50%, 25% and 12.5%. Statistical tests used were paired t-tests, one-way anova, Tukey's test, Kruskal-Wallis test and Dunn's post-test.

RESULTS

The [NaF 12 g L^-1  + NaCl 1 g L^-1 ] solution did not modify dentine microhardness or the average dentinal tubule area. However, EDTA induced changes in dentine structure and microhardness (P < 0.05). The [NaF 12 g L^-1  + NaCl 1 g L^-1 ] solution, and its NiTi-containing product had lower cytotoxicity than NaOCl at dilutions of 25% and 50% (P < 0.01).

CONCLUSIONS

The [NaF 12 g L^-1  + NaCl 1 g L^-1 ] solution did not alter dentine microhardness or damage the dentine structure. It also demonstrated lower cytotoxicity than NaOCl.

Effect of Silver Diamine Fluoride and Potassium Iodide Treatment on Secondary Caries Prevention and Tooth Discolouration in Cervical Glass Ionomer Cement Restoration

This study investigated the effect of silver diamine fluoride (SDF) and potassium iodide (KI) treatment on secondary caries prevention and tooth discolouration in glass ionomer cement (GIC) restoration. Cervical GIC restorations were done on 30 premolars with: Group 1, SDF + KI; Group 2, SDF (positive control); Group 3, no treatment (negative control). After cariogenic biofilm challenge, the demineralisation of dentine adjacent to the restoration was evaluated using micro-computed tomography (micro-CT) and Fourier transform infrared (FTIR) spectroscopy. The colour of dentine adjacent to the restoration was assessed using CIELAB system at different time points. Total colour change (∆E) was calculated and was visible if ∆E > 3.7. Micro-CT showed the outer lesion depths for Groups 1, 2 and 3 were 91 ± 7 µm, 80 ± 7 µm and 119 ± 8 µm, respectively (p < 0.001; Group 2 < Group 1 < Group 3). FTIR found that there was a significant difference in amide I-to-hydrogen phosphate ratio among the three groups (p < 0.001; Group 2 < Group 1 < Group 3). ∆E of Groups 1, 2 and 3 after biofilm challenge were 22.5 ± 4.9, 70.2 ± 8.3 and 2.9 ± 0.9, respectively (p < 0.001; Group 3 < Group 1 < Group 2). SDF + KI treatment reduced secondary caries formation on GIC restoration, but it was not as effective as SDF treatment alone. Moreover, a perceptible staining on the restoration margin was observed, but the intensity of discolouration was less than that with solely SDF treatment.

Evaluation of Vinegar as a Disinfectant for Extracted Human Teeth - An in-Vitro Study

INTRODUCTION

In dentistry, extracted human teeth are routinely used to learn technical and preclinical skills. Since human teeth harbour many pathogens these should be disinfected before use to minimize the risk of infections. Some commonly used disinfectants in laboratories are 10% formalin, 3% hydrogen peroxide (H2O2), 5.25% Sodium Hypochlorite (NaOCl), 70% alcohol and normal saline which have their own disadvantages like carcinogenicity, toxicity, cost effectiveness etc. Many studies have been conducted using these solutions but there is no evidence to suggest a suitable alternative for disinfecting extracted teeth. Vinegar is a sour liquid comprised mainly of acetic acid. It is cheap and commercially available shown to be effective in the prevention and control of microbial contamination.

AIM

The present study was conducted for evaluation of vinegar as a disinfectant for extracted teeth.

MATERIALS AND METHODS

In this study a total of 40 (n=40) extracted non carious teeth were taken which were disinfected with various physical methods such as sterilization, autoclaving and chemical methods by using Vinegar, 70% Alcohol, 10% Formalin, 3% Hydrogen peroxide and 5.25% NaOCL. Later, teeth from each group were placed individually in separate test tubes containing 10ml of brain heart infusion broth at 37°C for 48 hrs to observe the evidence of growth of microorganisms.

RESULTS

Results were analyzed using Kruskal-Wallis test. Vinegar, 10% Formalin and 3% Hydrogen peroxide were effective. The results were statistically significant with Kruskal-Wallis test value 28.053 and p-value was <0.001.

CONCLUSION

Vinegar can be used as an effective disinfectant for extracted human teeth.

A systematic review of randomized controlled trials on sterilization methods of extracted human teeth

Aim of this Study:

The aim was to evaluate the efficiency of different sterilization methods on extracted human teeth (EHT) by a systematic review of in vitro randomized controlled trials.

Methodology:

An extensive electronic database literature search concerning the sterilization of EHT was conducted. The search terms used were “human teeth, sterilization, disinfection, randomized controlled trials, and infection control.” Randomized controlled trials which aim at comparing the efficiency of different methods of sterilization of EHT were all included in this systematic review.

Results:

Out of 1618 articles obtained, eight articles were selected for this systematic review. The sterilization methods reviewed were autoclaving, 10% formalin, 5.25% sodium hypochlorite, 3% hydrogen peroxide, 2% glutaraldehyde, 0.1% thymol, and boiling to 100°C. Data were extracted from the selected individual studies and their findings were summarized.

Conclusion:

Autoclaving and 10% formalin can be considered as 100% efficient and reliable methods. While the use of 5.25% sodium hypochlorite, 3% hydrogen peroxide, 2% glutaraldehyde, 0.1% thymol, and boiling to 100°C was inefficient and unreliable methods of sterilization of EHT.

Awareness and Knowledge of Undergraduate Dental Students about Sterilization/Disinfection Methods of Extracted Human Teeth

BACKGROUND

Dental undergraduate students work on extracted human teeth in preclinical practical's to learn technical skills before entering the clinics and delivering dental care to the patients.

AIM

The aim of the present investigation was to assess the awareness and knowledge toward sterilization/disinfection methods of extracted human teeth in a selected group of Indian dental students.

MATERIALS AND METHODS

In this descriptive cross-sectional study, the participants consisted of 2^nd-, 3^rd-, 4^th-, and 5^th-year dental students. Data were collected by questionnaires and analyzed by Mann-Whitney U-test and Kruskal-Wallis test using SPSS software version 16 for Windows (SPSS Inc., Chicago, IL, USA).

RESULTS

In this study, 235 dental students participated in the study. The average awareness and knowledge score was 7.27 (1.92). Based on the opinion of 57% (134/235) students, hydrogen peroxide was selected as the suitable material for sterilization and 24.6% (58/235) students believed that autoclave sterilization is a good way for the purpose.

CONCLUSION

The results of this investigation indicated that awareness and knowledge of undergraduate dental students in relation to sterilization/disinfection methods of extracted human teeth were good. However, deficiencies were observed in relation to teaching the material and methods suitable for sterilization.

Cariostatic effect of green tea in comparison with common anticariogenic agents: an in vitro study

Background and aims. Anticariogenic effects of different mouthrinses have been shown previously. In this in vitro study the anticariogenic effects of polyphenol extract of green tea with 0.05% fluoride, 0.2% chlorhexidine and fluoride-chlorhexidine were compared. Materials and methods. This in vitro study was performed on 50 maxillary premolars in 5 groups: 1) normal saline; 2) a 10% solution of green tea polyphenol extract; 3) 0.05% fluoride; 4) 0.2% chlorhexidine; and 5) fluoride-chlorhexidine. Each tooth was placed in a tube which contained a cariogenic solution. Every day the teeth were washed (depending on the experimental groups) with 5 mL of mouthrinse solution. The depth of the caries was measured under a polarized light microscope. Data were analyzed using SPSS 13.0 with Kolmogorov-Smirnov, one-way ANOVA and Tukey tests. Results. The mean and standard deviation (in µm) of caries depth were 194±16.43, 175±17.94, 142±9.34, 155±13.27, and 144±8.57 in groups 1 to 5, respectively, with significant differences between the groups (P<0.001). Tukey test showed that although there was no significant difference in the depth of caries in groups 1 and 2 (P>0.001), they were significantlyless than those in groups 3 to 5 (P<0.001). There was no significant difference between decay depth of groups 3, 4 and 5 (P>0.001). Conclusion. The anticariogenic effect of fluoride-chlorhexidine was the highest among the groups. Although green tea showed higher cariostatic effects than normal saline, in comparison with other mouthrinses, it is less effective. More re-search is strongly recommended for clinical use of green tea as an anticariogenic agent.

Impact of root canal preparation size and taper on coronal-apical micro-leakage using glucose penetration method

OBJECTIVES

The purpose of this in vitro study was to assess the effect of root canal preparation size and taper on the amounts of glucose penetration.

MATERIAL AND METHODS

For conducting this experimental study, eighty mandibular premolars with single straight canals were divided randomly into 2 experimental groups of 30 samples each and 2 control groups. Using K-files and the balance force technique, canals in group 1 were prepared apically to size 25 and coronally to size 2 Peesoreamer. Group 2 were instrumented apically and coronally to size 40 and size 6 Peesoreamer, respectively. Rotary instrumentation was accomplished in group 1; using size 25 and .04 tapered and in group 2, size 35 and .06 tapered Flex Master files. Canals were then obturated by lateral compaction of cold gutta-percha. Glucose penetration through root canal fillings was measured at 1, 8, 15, 22 and 30 days. Data were recorded as mmol/L and statistically analyzed with Mann-Whitney U test (P value=. 05).

RESULTS

In comparison to group 1, group 2 showed significant glucose leakage during the experimental period (P value < .0001). Also, in each experimental group, the amount of micro-leakage was significantly increased at the end of the study.

CONCLUSIONS

Under the condition of this study, the amounts of micro-leakage through root canal fillings are directly related to the size and taper of root canal preparation and reducing the preparation size may lead to less micro-leakage. Key words:Dental leakage, root canal preparation, endodontics.

Biological Restoration of a Fractured Anterior Tooth with the Use of Dentine Pin (Biopins)

This case study describes the esthetic and functional reconstruction of a fractured maxillary central incisor. Due to the requirement for additional retention, treatment was performed using the homogenous technique of biological restoration associated with cementation of posts made from human dentin (biopins). This type of treatment is a new alternative to conventional techniques and favors the dental esthetic and function, as well as biocompatibility, and is an inexpensive procedure.

Effect of carbon dioxide laser irradiation on enamel surface microhardness around orthodontic brackets

INTRODUCTION

In this study, we aimed to determine the effect of carbon dioxide laser irradiation on enamel surface microhardness.

METHODS

In this single-blind interventional clinical trial, 16 patients needing at least 2 premolars extracted for orthodontic purposes participated. In each subject, 1 premolar was treated with the carbon dioxide laser (beam diameter, 0.2 mm; power, 0.7 W); the other was exposed to a visible guiding light as the control. A t-loop was ligated to the bonded brackets to increase caries risk. After at least 2 months, the teeth were extracted, and the surface microhardness was measured. Scanning electron microscope evaluation was performed on 1 sample from each group. Normal distribution of the data was assessed by the Kolmogorov-Smirnov and Shapiro-Wilks tests. Mean microhardness values of the 2 groups were compared using paired t tests.

RESULTS

The data had normal distributions. Means and standard deviations of the microhardness in the laser-treated and control groups were 301.81 ± 94.29 and 183.9 ± 72.08 Vickers hardness numbers, respectively; this was different significantly (P <0.001). Scanning electron microscopy showed the enamel surface melting in the laser-treated specimens.

CONCLUSIONS

Carbon dioxide laser treatment results in higher enamel surface microhardness around orthodontic brackets. Patients at high risk of caries might benefit from this intervention. Exact control of the laser irradiation parameters is recommended.

Knowledge, attitudes, and performance of dental students in relation to sterilization/disinfection methods of extracted human teeth

BACKGROUND

Dental students use extracted human teeth to learn practical and technical skills before they enter the clinical environment. In the present research, knowledge, performance, and attitudes toward sterilization/disinfection methods of extracted human teeth were evaluated in a selected group of Iranian dental students.

MATERIALS AND METHODS

In this descriptive cross-sectional study the subjects consisted of fourth-, fifth- and sixth-year dental students. Data were collected by questionnaires and analyzed by Fisher's exact test and Chi-squared test using SPSS 11.5.

RESULTS

In this study, 100 dental students participated. The average knowledge score was 15.9 ± 4.8. Based on the opinion of 81 students sodium hypochlorite was selected as suitable material for sterilization and 78 students believed that oven sterilization is a good way for the purpose. The average performance score was 4.1 ± 0.8, with 3.9 ± 1.7 and 4.3 ± 1.1 for males and females, respectively, with no significant differences between the two sexes. The maximum and minimum attitude scores were 60 and 25, with an average score of 53.1 ± 5.2.

CONCLUSION

The results of this study indicated that knowledge, performance and attitude of dental students in relation to sterilization/disinfection methods of extracted human teeth were good. However, weaknesses were observed in relation to teaching and materials suitable for sterilization.

Antimicrobial activity of calcium hydroxide and chlorhexidine on intratubular Candida albicans

This study investigated the efficacy of calcium hydroxide and chlorhexidine gel for the elimination of intratubular Candida albicans (C. albicans). Human single-rooted teeth contaminated with C. albicans were treated with calcium hydroxide, 2% chlorhexidine gel, calcium hydroxide plus 2% chlorhexidine gel, or saline (0.9% sodium chloride) as a positive control. The samples obtained at depths of 0–100 and 100–200 µm from the root canal system were analyzed for C. albicans load by counting the number of colony forming units and for the percentage of viable C. albicans using fluorescence microscopy. First, the antimicrobial activity of calcium hydroxide and the 2% chlorhexidine gel was evaluated by counting the number of colony forming units. After 14 days of intracanal medication, there was a significant decrease in the number of C. albicans colony forming units at a depth of 0–100 µm with chlorhexidine treatment either with or without calcium hydroxide compared with the calcium hydroxide only treatment. However, there were no differences in the number of colony forming units at the 100–200 µm depth for any of the medications investigated. C. albicans viability was also evaluated by vital staining techniques and fluorescence microscopy analysis. Antifungal activity against C. albicans significantly increased at both depths in the chlorhexidine groups with and without calcium hydroxide compared with the groups treated with calcium hydroxide only. Treatments with only chlorhexidine or chlorhexidine in combination with calcium hydroxide were effective for elimination of C. albicans.

Sterilization of extracted human teeth: A comparative analysis

BACKGROUND

Extracted human teeth are regularly used for practice and educational purposes in dental institutions at undergraduate and postgraduate levels. Different materials and methods are used for sterilizing extracted teeth to avoid infection from them.

AIMS

The present study was done to determine the efficacy of some frequently used methods for disinfection/sterilization of extracted human teeth.

MATERIALS AND METHODS

A total of 120 intact, non-carious teeth extracted due to periodontal or orthodontic purpose were divided randomly into 8 groups consisting of 15 teeth in each group. Agents used for sterilization included 10% formalin, 0.1% thymol in distilled water, 5.25% sodium hypochlorite, 2% glutaraldehyde, 3% hydrogen peroxide, boiled in water (100 °C), autoclave (121 °C, 15 lbs psi), normal saline. Samples were collected with the help of inoculating loop and then streaked over the surface of Mc-Conkey agar medium and Blood agar medium. The media were then incubated at 37 °C for 24 h. No visible growth in the culture medium was considered as the method of effective sterilization.

RESULTS

10% formalin, autoclaving, 5.25% sodium hypochlorite could be efficiently used for sterilization and disinfection of extracted human teeth.

CONCLUSION

Extracted teeth should be handled with extreme care as these are potential source of infection and need to be disinfected before they are used in the laboratories.

The comparison of MTA, Geristore® and Amalgam with or without Bioglass as a matrix in sealing the furcal perforations (in vitro study)

AIM

The objective of this in vitro was to assess the sealing ability of MTA, Geristore®, and amalgam with and without Bioglass as a matrix used to repair furcation perforations in mandibular molars by using dye penetration.

MATERIALS AND METHODS

One hundred mandibular molars were randomly divided into six experimental groups. Five teeth with perforation were used as positive control while five teeth without perforation were used as negative control group. Furcal perforations were made in the teeth. Perforations were repaired with amalgam in group 1, amalgam and Bioglass in group 2, MTA in group 3, MTA and Bioglass in group 4, Geristore® in group 5, and Geristore® and Bioglass in group 6. All repairing materials were allowed to set for 72 h. Leakage at the repaired sites was then evaluated using dye penetration and clearing technique under stereomicroscope.

RESULTS

The perforations repaired with MTA and Geristore® leaked significantly less than amalgam (p = 0.000). Bioglass reduced sealing ability of MTA and Geristore® significantly (p = 0.000, p = 0.019), while reduced the sealing ability of amalgam insignificantly (p = 0.78).

CONCLUSION

MTA and Geristore® have shown acceptable sealing ability in furcal perforation in comparison to amalgam while Bioglass as a matrix beneath them has reduced their sealing ability.