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Purpose: To compare the connection microgaps and the bacterial infiltration of implant-abutment interfaces of two extraoral implant models. Materials and Methods: Two implant models were used: the inner connection and the flush connection types. The implant-abutment microgaps of five sets of each extraoral implant were evaluated with scanning electron microscopy. Eleven additional sets of each model design were immersed in Staphylococcus aureus cultures for 24 hours, and samples were obtained from the external surface and from the implant's internal chamber to quantify the colony-forming units. Results: Scanning electron microscopy analysis showed that microgaps of the flush connection were smaller compared with the inner connection (P < .0001), and that bacterial counts were higher at the inner connection compared with the flush connection (P < .0001). Conclusion: Within the limitations of this experimental study, it can be concluded that the flush connection model presented a smaller microgap and fewer bacterial colonies compared with the inner connection model. [ABSTRACT FROM AUTHOR]

The microbial leakage at the implant-abutment interface (IAI) is one cause of peri-implant infection that puts long-term implant stability at risk. The present study compared two types of Morse taper implants in terms of sealing performance at the implant-healing abutment interface. Three implant systems, one of which exhibited a partial face-contact design (TSO) and the other two a line-contact design (TSM and BLT), were analyzed in vitro using two quantitative implant leakage measuring techniques: air-injection pressure measurement test and microbial examination. An in-house-developed device was used to determine implant leakage by recording the initial drop in pressure while injecting air through the implant. The microbial examination measured the absorbances of culture mediums in which the inoculated implants were contained. Significant difference was found between the partial face- and line-contact groups (p<0.001). Both tests revealed that partial face-contact implants are more prone to leakage than line-contact implants. [ABSTRACT FROM AUTHOR]

Nowadays, the use of nanoparticles (NPs) has become useful in the different application fields. The aim of this study was to investigate the in vitro antimicrobial potential of metalZnO nanoparticles (ZnO NPs) against several bacterial and fungal strains including; Escherichia coli (ATCC 25922), Bacillus cereus (ATCC 13753), Staphylococcus aureus (ATCC 8095), Pseudomonas aeruginosa (ATCC10662), Candida albicans (ATCC10231) and Aspergillus niger (AUMC3663). Results obtained by X-ray diffraction analysis (XRD) showed that the NPs size was in the range of 35.1- 43.7 nm. Images of the scanning electron microscopy (SEM) demonstrated the rod shape nature of the ZnO NPs, and the semi-spherical shapes of the Zn9.7TM0.3O NPs. The effect of different concentrations of ZnO NPs on the in vitro growth of the bacterial and fungal strains was evaluated using the agar well diffusion assay. Current results showed that Cd-ZnO NP recorded the highest antimicrobial potency; expressing inhibition zones diameter range of 12- 45 mm, while ZnO NPs demonstrated the least activity exhibiting inhibition zones diameter that ranged from 0- 36 mm. Among all the examined ZnO-NPs, treatment of E. coli and Staph. aureus cells with Cd-ZnO proved to be the most effective in causing membrane leakage of reducing sugars, protein and DNA recording; 0.41 µg/ ml and 0.38 µg/ ml; 14.91 µg/ ml and 15.98 µg/ ml; 0.81 µg/ ml and 0.96 µg/ ml, respectively. This study emphasized that ZnO NPs could be used as alternative antimicrobial agents to control the bacterial and fungal pathogens. Manipulation of ZnO NPs is ecofriendly; as it reduces the use of the synthetic pesticides and chemical therapeutic agents, which pollute the environment. In the future, in vivo application of these NPs necessitates the proof that they have no phytotoxicity and\or cytotoxicity.

Aim: To compare the microbial leakage of three root canal filling materials: AH Plus with Gutta-percha, Epiphany with Resilon, and Guttaflow using Enterococcus faecalis as the bacterial marker. Materials and Methods: In total, 30 caries free, human maxillary incisors with straight roots were used. The teeth were de-coronated with a diamond disc and the length was standardized for all specimens. Access opening was done through the coronal portion and the working length was determined. All the teeth were prepared to a standardized size apically and coronally. The teeth were then randomly divided into three experimental groups each. After obturation of the root canals, the outer surfaces of the teeth were coated with two layers of nail enamel except the apical 2 mm. The teeth were then subjected for bacterial leakage test using E. faecalis as a bacterial marker in dual chamber bacterial leakage model for a period of 30 days. Statistical Analysis Used: Chi-square test. Results: Results showed that Resilon/Epiphany (Group-2) demonstrated less leakage and Gutta-percha/AH Plus (Group-1) showed maximum leakage with the statistically significant difference between the two (P < 0.05). Guttaflow (Group-3) also showed less leakage than Gutta-percha/AH Plus (Group-1) with the statistically significant difference between the two (P < 0.05). There was no statistically significant difference between Resilon/Epiphany (Group-2) and Guttaflow (Group-3). Conclusion: Resilon/Epiphany and Guttaflow groups demonstrated less microbial leakage than Gutta-percha/AH Plus group.

Objectives: The purpose of this systematic review of the literature is to investigate which of the epoxy-based cements and those based on Tricalciumsilicate (MTA, Bioceramic) have the best sealing capacity through the analysis of studies that have provided a survey model in vitro of bacteria leakage. Source: The articles were identified using electronic databases such as PubMed, Scopus, the search was conducted between 8.12.2020 and 31.12.2020 and a last search was conducted on 2.12.2021. Study selection: 678 records were identified and after removing the duplicates we obtain 481 records, with the first phase of screening and selection of records we reached 204 and with the application of the inclusion and exclusion criteria we selected 31 articles, only 9 studies made a direct comparison between the two endodontic cement categories and presented data that could be included in the metaanalysis. Data: The meta-analysis of first outcome shows an odds ratio of 2.70 C.I.(Confidence Interval) [1.54, 4.73], the test for overall effect has a p value = 0.0005 with a heterogeneity index of I 2 of 9%; The second outcome meta-analysis shows an Odds Ratio of 1.50 C.I. (Confidence Interval) [0.92, 2.46] with a p value of 0.10 with an I 2 of 79%. Conclusion: the sealing ability is higher for epoxy resins than for tricalcium silicate-based cements, for observation periods longer than 90 days. Clinical relevance: The knowledge of the cement that determines the best sealing ability and resistance to microbial leakage, can be of help for the dentist who has to face clinical situations such as endodontic retreatments whose failure is determined by the persistence of bacteria in the endodontic canals.

Aim: To compare the microbial leakage of three root canal filling materials: AH Plus with Gutta-percha, Epiphany with Resilon, and Guttaflow using Enterococcus faecalis as the bacterial marker.Materials and Methods: In total, 30 caries free, human maxillary incisors with straight roots were used. The teeth were de-coronated with a diamond disc and the length was standardized for all specimens. Access opening was done through the coronal portion and the working length was determined. All the teeth were prepared to a standardized size apically and coronally. The teeth were then randomly divided into three experimental groups each. After obturation of the root canals, the outer surfaces of the teeth were coated with two layers of nail enamel except the apical 2 mm. The teeth were then subjected for bacterial leakage test using E. faecalis as a bacterial marker in dual chamber bacterial leakage model for a period of 30 days.Statistical Analysis Used: Chi-square test.Results: Results showed that Resilon/Epiphany (Group-2) demonstrated less leakage and Gutta-percha/AH Plus (Group-1) showed maximum leakage with the statistically significant difference between the two (P < 0.05). Guttaflow (Group-3) also showed less leakage than Gutta-percha/AH Plus (Group-1) with the statistically significant difference between the two (P < 0.05). There was no statistically significant difference between Resilon/Epiphany (Group-2) and Guttaflow (Group-3).Conclusion: Resilon/Epiphany and Guttaflow groups demonstrated less microbial leakage than Gutta-percha/AH Plus group. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to verify the presence of a microgap between implants and prosthetic abutments on their external surfaces in five different external-hex implant systems and to determine whether bacterial leakage occurs through the implant-abutment (I-A) interface. Materials and Methods: Ten samples of each implant system were used. Eight samples of each implant system were inoculated with 0.3 µL of a suspension of Escherichia coli for bacterial leakage evaluation. Two other samples were used as controls. Sample analysis was accomplished at 24 and 48 hours and on the 5th, 7th, and 14th day after inoculation. After microbiologic analysis, all samples were prepared for I-A interface evaluation by scanning electron microscopy. The mean of the microgap misfit was obtained from six points at ×1,000 and ×3,000 magnifications. Results: The Neodent implant system (0.51 ± 0.39 µm) showed the closest adaptation, followed by Dentoflex (1.44 ± 0.73 µm), Titanium Fix (1.88 ± 1.28 µm), SIN (2.46 ± 3.38 µm), and Conexão (2.68 ± 3.02 µm). Twenty-five percent of the Dentoflex samples showed bacterial leakage through the I-A interface; no other implant system presented bacterial leakage. Conclusion: The width of the microgap at the I-A interface was less than 3 µm in all systems. A direct correlation between bacterial leakage and I-A interface misfit was not observed. [ABSTRACT FROM AUTHOR]

Purpose: The aim of the present study was to histomorphometrically investigate crestal bone changes at nonsubmerged implants (Camlog) with different machined collar lengths in a dog model. Materials and Methods: One-stage insertion of sandblasted acid-etched screw-type implants with machined neck sizes of 1.6 mm (CAM) and 0.4 mm (CAM+) was performed in the mandibles of 4 beagle dogs. Both types of implants were inserted so that the implant shoulder (IC) exceeded the alveolar crest for 0.4 mm. Placement was followed by the connection of standard abutments. The animals were sacrificed after 2 and 12 weeks. Dissected blocks were processed for histomorphometric analysis (eg, distance between IC and the coronal extension of bone-implant contact [CBI], the distance between IC and the apical extension of the inflammatory cell infiltrate, and the percentage of bone-implant contact). Results: Histomorphometric analysis revealed significantly increased mean IC-CBI (CAM: 2.4 ± 0.3 mm; CAM+: 1.6 ± 0.1 mm) and BIC (CAM: 77%; CAM+: 80%) values in both groups at 12 weeks. However, mean IC-CBI values were significantly higher in the CAM group (P < .01). An inflammatory cell infiltrate was localized to the implant-abutment interface of both CAM and CAM+ implants, and BC was clearly separated from aICT by a subepithelial connective tissue zone. Conclusions: Within the limits of the present study, it was concluded that (1) rough-surfaced implant necks reduced crestal bone level changes after 12 weeks of healing, and (2) microbial leakage apparently did not contribute to the marginal bone resorption in either group. [ABSTRACT FROM AUTHOR]

Aim: The aim of this study was to evaluate the extent of microbial leakage of cotton, cellulose sponge and polytetrafluoroethylene tape (PTFE) tape used as spacers in an in vitro microbiologic model when impregnated with calcium hydroxide and iodoform based medicaments. Materials and Method: The study consisted of three groups of spacers: Group I: Cotton, Group II: Cellulose sponge and Group III: PTFE tape. The groups were further subdivided into 3 groups where spacers were used alone, impregnated with calcium hydroxide medicament and impregnated with iodoform based medicament. Forty five intact mandibular human premolars were used to check the access cavity bacterial contamination. The teeth were disinfected, pulpal remnants removed, and access cavities were swabbed with sterile cotton. Spacers were placed and the teeth were inoculated with Staphylococcus aureus bacteria in nutrient broth till cementoenamel junction. The access cavities were checked for contamination after 7 days by swabbing with sterile cotton and streaking the agar plates with the same. Bacterial colony formation was observed in all groups. Results: 82% of samples in the cotton spacer group showed colonies > 105 CFU/ml, while those impregnated with medicament showed colonies < 102 CFU/ ml. Conclusion: According to the present study, the effectiveness of the three materials when used with medicament is best in case of cotton followed by cellulose sponge. While in test groups where no medicament was used, PTFE tape was the most effective and cotton showed least potential against preventing bacterial uptake. Clinical significance: Microbes cause periapical inflammation entering coronally during endodontic treatment. Hence an efficient provisional restoration and an interim spacer material is of paramount importance. [ABSTRACT FROM AUTHOR]

Two-stage implant systems result in gaps and cavities between implant and abutment that can act as a trap for bacteria and thus possibly cause inflammatory reactions in the peri-implant soft tissues. These gaps between the components are inevitable, and their clinical significance has so far been mostly neglected by both manufacturers and clinicians. The aim of the study was to determine whether there is microbial leakage at the implant-abutment interface. Thirteen different implant-abutment combinations were subjected to an in vitro experiment, in which the penetration of bacteria (Escherichia coli) was observed for 10 assemblies of each type. All implant systems presented microbial leakage. When the Frialit-2 implant was supplied with a silicon washer, there were fewer cases of leakage. The width of the marginal gap between the prefabricated components, measured with a scanning electron microscope, was less than 10 µm in all systems. [ABSTRACT FROM AUTHOR]

Purpose To evaluate the quality of the apical 5-mm seal produced by different filling techniques using a bacterial leakage model. Materials and Methods Sixty-five extracted single-rooted human teeth were decoronated, prepared, and instrumented. Roots were randomly divided into three experimental groups (15 roots each) and control groups (10 roots each). The apical 5 mm was filled with cold lateral condensation (CLC) technique, continuous wave of condensation (CWC), or injectable thermoplasticized gutta-percha (Obtura II) using AH26 Plus as a sealer. Positive controls were filled with gutta-percha without sealer, whereas negative controls were filled with a CLC technique and covered completely with two layers of nail varnish, including the orifice. A dual-chamber leakage model using Enterococcus faecalis as a microbial marker was used for leakage evaluation. Bacterial penetration was monitored over a 60-day period, and leakage was recorded when turbidity was observed in the lower chamber. Results All positive controls exhibited turbidity in the lower chamber within 24 hours. All negative controls demonstrated no bacterial leakage for the entire 60-day observation period. The estimated mean day for leakage was 32 for CLC, 35 for CWC, and 30 days for Obtura II. Wilcoxon test showed no statistically significant difference ( p = 0.98) in the survival time between the experimental groups. Conclusion The three filling techniques produced similar resistance to bacterial leakage when used to fill the apical 5-mm segment of the canal while leaving the rest of the canal unfilled. [ABSTRACT FROM AUTHOR]

Background: Although implants have shown to have a high success rate, clinicians are also called upon to encounter numerous complications and failures. Among the numerous reasons of failures, peri-implantitis is reported to account for 10% of the failures. As the oral cavity provides a natural habitat for various micro-organism due to its non-shedding surface, there is some evidence that gram-negative anaerobic rods colonize around the implant leading to peri-implanitis. This colonization is dependent on various factors such as the micro-gap at the implant- abutment interface, the precision of fit, degree of micromovement and applied torque. Aim and Objective: The aim of this article is to provide an overview of current literature on bacterial colonization on the implant surface and the influence of different implantabutment designs on bacterial colonization. Material and Methods: An electronic search was conducted using the PubMed (Medline), PubMed central and Google scholar to identify articles published on bacterial colonization at the implant-abutment interface. The following search words were used: microbioleakage at implant-abutment interface, surface characteristics/roughness of implants, bacterial adhesion on dental implants, bacterial colonization at implant abutment surface. The articles included in the review comprises of in vitro studies, in vivo studies, review abstracts and review articles. Results: The total number of articles for the key words" microbioleakage at implantabutment interface" were 29 and for the key words" bacterial colonization at implant abutment interface" were 17. After considering the inclusive and exclusive criteria, case report, case series and review articles were excluded. 11 articles were considered eligible based on their relevance to the subject. Conclusion: Although micro-gap formation inevitably occurs at the implant-abutment interface. The current literature highlights that the formation of this micro-gap is influenced by the type of implant-abutment design used. Though the results are insignificant, recent in vivo and in vitro studies have proved that external hexagon results in higher micro leakage compared to other connections used .Morse-taper connections shows the least amount of microbial leakage. [ABSTRACT FROM AUTHOR]

Objective To evaluate the bacterial microflora present inside the implant connection and in the peri-implant sulcus fluid of healthy implants, and to analyze the relationships between these harboring sites for four different implant systems after at least 5 years of functional loading. Materials and methods A cross-sectional study was performed involving 40 patients treated with metal-ceramic cemented bridges supported by at least two healthy implants functionally loaded for 5 years. Four different implant-abutment connections were studied: external hexagon (control group), double internal hexagon (test group 1), internal hexagon with external collar (test group 2), and conical connection (test group 3). Samples for microbiological analysis were obtained from three types of sites: peri-implant sulci, connections' inside and abutments surface and, as control, gingival sulci of neighboring teeth. Quantitative real-time PCR was carried out for Total Bacterial Count and for 10 microorganisms: Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Tannerella forsythensis, Treponema denticola, Prevotella intermedia, Peptostreptococcus micros, Fusobacterium nucleatum, Campylobacter rectus, Eikenella corrodens, and Candida albicans. The response variables were percentage of positive sites and absolute bacterial load. The relations of the response variables with the type of connection and of sampling site were assessed using generalized estimating equations. Results Regarding the analysis of positivity to bacteria in the peri-implant sulcus no significant differences were observed. Analyzing the connection's inside, none of the connection designs had the capacity to prevent microbiological leakage through the implant/abutment microgap. Test group 3 presented the lowest mean values for red complex bacteria and control group the highest, although differences were non-significant. Statistical significance was only reached for Treponema denticola in the bacterial load analysis inside the connection. Test groups 1 and 2 yielded lower values for orange complex bacteria but only for Peptostreptococos micros the differences resulted significant. Test groups 2 and 3 had significantly lower total bacterial counts in the peri-implant sulcus and inside the connection. Conclusions Outcomes suggested that all the analyzed connections resulted contaminated after 5 years of functional loading. However, the connection design might influence bacterial activity levels qualitatively and quantitatively, especially inside the implant connection. [ABSTRACT FROM AUTHOR]

Prevention of microbial leakage at the implant-abutment junction is a major challenge for the construction of 2-stage implants in order to minimize inflammatory reactions and to maximize bone stability at the implant neck. The aim of the present in vitro study was an evaluation of the leakage observed over a period of 28 days in Cone Morse taper internal connections and in screwed-abutments connections. In the present study 10 specimens of Cone Morse (Group 1) and 10 of internal hexagon (Group 2) implants were used. The inner parts of 5 implants per group were inoculated with Pseudomonas aeruginosa (PS) suspension and 5 implants per group with Aggregatibacter actinomycetemcomitans (AA). The possible penetration of bacterial suspension into the surrounding solution was determined by the observation of turbidity of the broth. In Group 1, bacterial contamination was found in 3 out of 5 implant-abutment assemblies seeded with the PS and in 2 samples out of 5 in the assemblies seeded with AA, with a total of leaked assemblies in this group of 5 out of 10. In Group 2, bacterial contamination was found in 4 out of 5 implant-abutment assemblies seeded with the PS, and in 4 out of 5 samples seeded with AA, with a total of leaked assemblies of 8 out of 10. The present data confirm the reported high permeability to bacterial leakage of screw-retained abutment connections, and the lower infiltration rates--although not significantly--of Cone Morse taper internal connections. [ABSTRACT FROM AUTHOR]

The microbial leakage at the implant-abutment interface (IAI) is one cause of peri-implant infection that puts long-term implant stability at risk. The present study compared two types of Morse taper implants in terms of sealing performance at the implanthealing abutment interface. Three implant systems, one of which exhibited a partial face-contact design (TSO) and the other two a line-contact design (TSM and BLT), were analyzed in vitro using two quantitative implant leakage measuring techniques: air-injection pressure measurement test and microbial examination. An in-house-developed device was used to determine implant leakage by recording the initial drop in pressure while injecting air through the implant. The microbial examination measured the absorbances of culture mediums in which the inoculated implants were contained. Significant difference was found between the partial face- and line-contact groups (p<0.001). Both tests revealed that partial face-contact implants are more prone to leakage than line-contact implants.

Microorganisms from the oral cavity may settle at the implant-abutment interface (IAI). As a result, tissue inflammation could occur around these structures. The databases MEDLINE/PubMed and PubMed Central were used to identify articles published from 1981 through 2012 related to the microbial colonization in the implant-abutment gap and its consequence in terms of crest bone loss and osseointegration. The following considerations could be put forward, with respect to the clinical importance of IAI: (a) the space present at the IAI seems to allow bacterial leakage to occur, in spite of the size of this space; (b) bacterial leakage seems to occur at the IAI, irrespective of the type of connection. More studies are necessary to clarify the relationship between leakage at IAI and abutment connection designs; (c) losses at the peri-implant bone crests cannot be related to the IAI size, since few studies have shown no relationship. Also, the microbial leakage at the IAI cannot be related to the bone crest loss, since there are no articles reporting this relationship; remains controversial the influence of the IAI position on the bone crest losses. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 101B: 1321-1328, 2013. [ABSTRACT FROM AUTHOR]

Objectives: The purpose of this systematic review of the literature is to investigate which of the epoxy-based cements and those based on Tricalciumsilicate (MTA, Bioceramic) have the best sealing capacity through the analysis of studies that have provided a survey model in vitro of bacteria leakage., Source: The articles were identified using electronic databases such as PubMed, Scopus, the search was conducted between 8.12.2020 and 31.12.2020 and a last search was conducted on 2.12.2021., Study Selection: 678 records were identified and after removing the duplicates we obtain 481 records, with the first phase of screening and selection of records we reached 204 and with the application of the inclusion and exclusion criteria we selected 31 articles, only 9 studies made a direct comparison between the two endodontic cement categories and presented data that could be included in the metaanalysis., Data: The meta-analysis of first outcome shows an odds ratio of 2.70 C.I.(Confidence Interval) [1.54, 4.73], the test for overall effect has a p value = 0.0005 with a heterogeneity index of I 2 of 9%; The second outcome meta-analysis shows an Odds Ratio of 1.50 C.I. (Confidence Interval) [0.92, 2.46] with a p value of 0.10 with an I 2 of 79%., Conclusion: the sealing ability is higher for epoxy resins than for tricalcium silicate-based cements, for observation periods longer than 90 days., Clinical Relevance: The knowledge of the cement that determines the best sealing ability and resistance to microbial leakage, can be of help for the dentist who has to face clinical situations such as endodontic retreatments whose failure is determined by the persistence of bacteria in the endodontic canals., Competing Interests: The authors declare no conflict of interest., (© 2021 The Author(s).)

Abstract: The purpose of this study was to evaluate polymicrobial coronal leakage of mineral trioxide aggregate (MTA) and amalgam. There were 108 single-rooted teeth randomly divided into 3 groups of 32 teeth each and positive and negative control groups of 6 teeth and obturated with gutta percha and either Diaket (3M/ESPE, Seefeld, Germany), AH Plus (Dentsply, De Trey, Konstanz, Germany), or Ketac Endo (3M/ESPE). These groups were further divided into 2 subgroups of 16 teeth in which root ends were resected and obturated with either MTA or zinc-free amalgam. The samples have been incorporated in a dual-chamber leakage model with a polymicrobial marker of five facultative anaerobes on the coronal part. Leakage was observing during a period of 90 days. The least leakage was found in a combination of Diaket and MTA (76.9 ±14.8 days) followed by AH Plus and MTA (66.1 ± 18.7), Diaket and amalgam (60.0 ± 23.1), AH Plus and amalgam (56.9 ± 22.1), and Ketac Endo and MTA (42.1 ± 17.8), whereas the greatest leakage was observed in the Ketac Endo and amalgam group (40.0 ± 17.24). Samples filled with MTA showed significantly better sealing than samples filled with amalgam (p < 0.05). [Copyright &y& Elsevier]

Aim: To compare the microbial leakage of three root canal filling materials: AH Plus with Gutta-percha, Epiphany with Resilon, and Guttaflow using Enterococcus faecalis as the bacterial marker., Materials and Methods: In total, 30 caries free, human maxillary incisors with straight roots were used. The teeth were de-coronated with a diamond disc and the length was standardized for all specimens. Access opening was done through the coronal portion and the working length was determined. All the teeth were prepared to a standardized size apically and coronally. The teeth were then randomly divided into three experimental groups each. After obturation of the root canals, the outer surfaces of the teeth were coated with two layers of nail enamel except the apical 2 mm. The teeth were then subjected for bacterial leakage test using E. faecalis as a bacterial marker in dual chamber bacterial leakage model for a period of 30 days., Statistical Analysis Used: Chi-square test., Results: Results showed that Resilon/Epiphany (Group-2) demonstrated less leakage and Gutta-percha/AH Plus (Group-1) showed maximum leakage with the statistically significant difference between the two (P < 0.05). Guttaflow (Group-3) also showed less leakage than Gutta-percha/AH Plus (Group-1) with the statistically significant difference between the two (P < 0.05). There was no statistically significant difference between Resilon/Epiphany (Group-2) and Guttaflow (Group-3)., Conclusion: Resilon/Epiphany and Guttaflow groups demonstrated less microbial leakage than Gutta-percha/AH Plus group., Competing Interests: None

Background: The endodontic spacers are placed between the endodontic appointments or after completion of the endodontic therapy, and until the placement of a definitive restoration., Aims: The aim of this study was to evaluate the sealing ability of polytetrafluoroethylene (PTFE) access spacer against microbial leakage and to compare it with that of a cotton pellet., Materials and Methods: Fifty-two extracted human single-rooted premolars were divided into two experimental groups ( n = 20) according to the endodontic spacer; cotton pellet or PTFE tape, and two control groups ( n = 6). Following standardized access cavity, cleaning, and shaping procedures, the access cavities received a standardized thickness of the spacer material followed by a Cavit restoration in all the teeth except for the positive controls, which were left empty. Negative controls had the root surfaces completely sealed with nail polish. A dual-chamber microbial leakage model was used with Enterococcus faecalis as the test strain. At days 7 and 30, samples of the lower chambers' solution were obtained and subjected to the quantitative real-time polymerase chain reaction (qPCR) analysis to quantify bacterial levels. Furthermore, broth turbidity in the lower chambers was recorded weekly. The Mann-Whitney U test and Wilcoxon test were used to compare E. faecalis counts between and within groups, respectively., Results: At days 7 and 14, the experimental groups leaked similarly as determined by broth turbidity. However, at days 21 and 30, a significantly higher number of cotton pellet samples exhibited microbial leakage. Analysis by qPCR revealed higher levels of E. faecalis counts in cotton pellet samples compared with PTFE samples. This difference was statistically significant at day 7, but not at day 30., Conclusions: PTFE spacer showed improved sealing ability compared with the commonly used cotton pellet and may serve as an alternative endodontic access cavity spacer., Competing Interests: There are no conflicts of interest., (Copyright: © 2019 Journal of Conservative Dentistry.)

Objective: PTFE tape, which is commonly used as plumber's tape is an inorganic, non-fibrous, ribbon like material. The aim of this study was to evaluate PTFE tape as endodontic spacer material and to compare it with commonly used spacer material that is cotton, in primary teeth., Study Design: Seventeen children undergoing pulpectomy of lower second primary molar bilaterally were included in the study. Cotton and PTFE tape were placed as spacers on each side randomly. Samples were taken from the access cavity at baseline and after seven days to check for microbial leakage. Spacer materials were also checked for microbial contamination., Results: The results revealed that there was a significant increase in the bacterial colony count after seven days in cotton group. The access cavities were also positive for microbial leakage in the cotton group where the spacers showed positive growth. In PTFE group only two samples showed microbial contamination of spacer and out of two only one sample showed contamination of access cavity along with spacer., Conclusion: Within the limitations of this study, it can be concluded that PTFE tape performed better than cotton as endodontic spacer material. Thus, PTFE tape can be recommended as an endodontic spacer material as an alternative to cotton in primary teeth.

Background: The aim of this research was to compare the apical sealing ability of different root-end filling materials (SuperEBA(®), ProRoot MTA(®), thermoplasticized gutta-percha + AH-Plus(®), thermoplasticized RealSeal(®)), by means of microbial indicators., Materials and Methods: Thus, 50 human single-rooted teeth were employed, which were shaped until size 5 0, retro - prepared with ultrasonic tips and assigned to 4 groups, retro-filled with each material or controls. A platform was employed, which was split in two halves: upper chamber-where the microbial suspension containing the biological indicators was introduced (E. faecalis + S. aureus + P. aeruginosa + B. subtilis + C. albicans); and a lower chamber containing the culture medium brain, heart influsion, where 3 mm of the apical region of teeth were kept immersed. Lectures were made daily for 60 days, using the turbidity of the culture medium as indicative of microbial contamination. Statistical analyses were carried out at 5% level of significance., Results: The results showed microbial leakage at least in some specimens in all of the groups. RealSeal(®) has more microbial leakage, statistically significant, compared to ProRoot(®) MTA and SuperEBA(®). No significant differences were observed when compared ProRoot(®) MTA and SuperEBA(®). The gutta-percha + AH Plus results showed no statistically significant differences when compared with the other groups., Conclusions: All the tested materials showed microbial leakage. Root-end fillings with Super-EBA or MTA had the lowest bacterial filtration and RealSeal shows highest bacterial filtration.