|Year : 2021 | Volume
| Issue : 3 | Page : 139-143
Microbiologic evaluation of cotton, polytetrafluoroethylene tape, and foam as an endodontic spacer material in permanent premolars and molars: An ex vivo study
Nidhi Surendra Pisal, Nimisha Chinmay Shah, Meetkumar S Dedania, Namrata Anil Bajpai, Namita Gandhi
Department of Conservative Dentistry and Endodontics, K. M. Shah Dental College and Hospital, Sumandeep Vidyapeeth, Vadodara, Gujarat, India
|Date of Submission||11-Apr-2021|
|Date of Decision||24-Jul-2021|
|Date of Acceptance||12-Aug-2021|
|Date of Web Publication||30-Sep-2021|
Dr. Nimisha Chinmay Shah
Department of Conservative Dentistry and Endodontics, K. M. Shah Dental College, Vadodara - 391 760, Gujarat
Source of Support: None, Conflict of Interest: None
Aims: Microbiologic evaluation of cotton, polytetrafluoroethylene (PTFE) tape, and foam as an endodontic spacer material in permanent premolars and molars – an ex vivo study.
Subjects and Methods: After ethical approval, 72 patients who signed the informed consent form participated in the study. Following access opening and biomechanical preparation, the teeth were randomly assigned to cotton (n = 24), PTFE tape (n = 24), and foam group (n = 24). Samples obtained from the access cavity at baseline (sample one – S1) and after seven days (sample two – S2) were checked for an increase in the microbial load. They were placed on brain-heart infusion agar plates, incubated aerobically for 48 h, and the colony-forming units were calculated.
Statistical Analysis: One-way analysis of variance and Tukey's post hoc test were used and a P < 0.05 was considered statistically significant.
Results: There was a statistically significant difference in all the three groups concerning baseline and after Seven-day mean values. An intergroup comparison revealed a statistically significant difference in the mean difference values between the cotton and PTFE tape group. Whereas, there was no statistically significant difference in the mean difference values between the cotton and foam and PTFE tape and foam group.
Conclusions: Within the limitations of the study, it can be stated that the PTFE tape and foam group performed better than cotton.
Keywords: Cotton, endodontic spacer, foam, inter-appointment dressing, polytetrafluoroethylene tape
|How to cite this article:|
Pisal NS, Shah NC, Dedania MS, Bajpai NA, Gandhi N. Microbiologic evaluation of cotton, polytetrafluoroethylene tape, and foam as an endodontic spacer material in permanent premolars and molars: An ex vivo study. Endodontology 2021;33:139-43
|How to cite this URL:|
Pisal NS, Shah NC, Dedania MS, Bajpai NA, Gandhi N. Microbiologic evaluation of cotton, polytetrafluoroethylene tape, and foam as an endodontic spacer material in permanent premolars and molars: An ex vivo study. Endodontology [serial online] 2021 [cited 2022 May 23];33:139-43. Available from: https://www.endodontologyonweb.org/text.asp?2021/33/3/139/327268
| Introduction|| |
Microbial infection is the most common cause of endodontic infections. Thus, the purpose of root canal treatment is to create a biologically acceptable environment within the root canal system which allows the healing and continued maintenance of the health of the periradicular tissue. This goal is achieved by eliminating the bacteria from within the root canal system and sealing the root canal and tooth to prevent reinfection. It is well established that the coronal seal is as important as the root canal filling. This is true even in the inter-appointment period of multiple-visit endodontics.
Consequently, the role of endodontic spacers and temporary restorative material comes into the picture. Out of all the properties for an ideal restorative material, the most crucial one is for it to have minimal or no leakage. The use of cotton as an endodontic spacer was advocated widely in the literature from the late 1970s. The advantage of cotton is the ease of removal of the temporary restoration without running the risk of unnecessary removal of intact tooth structure or even worse, perforating the floor of the pulp chamber. However, the thickness of the provisional material could be reduced, it may act as a cushion during placement, and the stability of the restoration can be compromised.
On that account, many clinicians have tried other materials such as foam and polytetrafluoroethylene (PTFE) tape, as spacers., PTFE tape is an inorganic, nonfibrous, ribbon-like material. It is inorganic, which reduces the potential for bacterial uptake by wicking. It is nonfibrous, thus reducing the chances of it getting impregnated within the temporary restorative material. It is nonspongy, thus allowing better support to the overlying temporary restorative material. In recent publications, the use of PTFE tape is advised in dentistry in several fields such as adhesive dentistry, prosthodontics and implant dentistry, endodontics. Previous research on PTFE tape as an endodontic spacer has shown good results in vitro and in vivo in permanent teeth.,,
The endodontic sponges serve as chairside storage and mechanical cleaning aid of root canal instruments. However, its use as an endodontic spacer has been only mentioned and not explored in any clinical study. Therefore, the aim of this study is comparative microbiological evaluation of cotton, PTFE tape, and foam as endodontic spacer material, ex vivo in permanent premolars, and molars. The null hypothesis was that there will be no difference between microbial leakage of cotton, PTFE tape, and foam as an endodontic spacer material in permanent premolars and molars during root canal treatment.
| Subjects and Methods|| |
Prior ethical approval was obtained from the Institutional Ethics Committee (SVIEC/ON/Dent/SRP/19129). Minimum 72 samples (24 per group) were required to estimate the mean difference in reduction of microbial leakage between groups by log10 80 with SD of log10 65 at 99% confidence and 90% power including dropout. Patients between 18 and 60 years of age who signed informed consent forms were included in the study. 72 patients indicated for at least two appointments endodontic therapy requiring a spacer with a pulpal diagnosis of symptomatic and asymptomatic irreversible pulpitis, pulpal necrosis, and at least three remaining intact coronal walls in premolars and molars were included in the study. The exclusion criteria were teeth with acute apical abscess, phoenix abscess, periapical cyst, perforations, developmental anomaly or congenital defects, patients on antibiotic therapy, with systemic conditions – immunocompromised conditions and pregnant women, patients with fractured or dislodged restoration during the study duration (1 week).
Local anesthetic agent Ligno-AD (Lignocaine hydrochloride IP –20 mg and adrenaline bitartrate – 0.01 mg) was administered when required, caries excavation, and straight-line access cavity was prepared with endo access and endo Z (Dentsply) bur attached to airotor handpiece. Rubber dam disinfection was carried out with 3% sodium hypochlorite. In the case of a Class II cavity, the preendodontic build-up was done with composite followed by rubber dam isolation. Rubber dam seal material was used in case of any leakage. Working length was determined using an electronic apex locator (Root X mini–J Morita) and confirmed with a radiograph. Copious irrigation was carried out with sodium hypochlorite and saline and in case of a vital tooth and chlorhexidine and saline in case of a necrosed tooth. Biomechanical preparation was carried out using step-back, crown-down, or hybrid technique according to canal anatomy and variations. After the biomechanical preparation, irrigation was done with 17% ethylenediaminetetraacetic acid for 1 min followed by final irrigation with saline. Before an inter-appointment dressing, the premolars and molars were equally divided into three groups by the computerized randomization method on the website-www.randomizer.org. Allocation concealment was done using sealed envelopes. Group A: Cotton as an endodontic spacer (n = 24), Group B: PTFE tape as an endodontic spacer (n = 24), Group C: Foam as an endodontic spacer (n = 24). Both the patients and microbiologists were blinded in the study. Each of the endodontic spacers was previously autoclaved in autoclavable pouches.
For each group, the chamber was dried and a sample one (S1) was collected by swabbing the pulp chamber with a sterilized cotton pellet after the completion of cleaning and shaping and before the placement of endodontic spacer. The S1 sample was collected in an Eppendorf tube containing ½ ml of brain-heart infusion (BHI) broth. The BHI broth mixed with each endodontic spacer was placed on a BHI agar plate. For 48 h, the agar plates were aerobically incubated and then the colony-forming units (CFUs) were measured. The CFUs in the S1 sample were considered as the baseline value. Calcium hydroxide (RC Cal) was placed as an intracanal medicament in the canals. The sterile spacer (cotton/foam/PTFE tape) was placed in the cavity with sterilized cotton pliers followed by the placement of a temporary restoration (Cavit 3M ESPE). Before discharging the patient, a bitewing radiograph was taken to make sure the thickness of the temporary restoration was 3–4 mm. At the second appointment, which was 1 week later, the temporary restoration was checked to make sure it is intact. It was previously determined that if the restoration was not intact between appointments, the tooth would not be considered for the study. Before removal of temporary restoration, single tooth rubber dam isolation was done. Following this, a sterile bur and handpiece were used to remove the restoration. A sterile tweezer was used to retrieve the endodontic spacer. The spacer was retrieved at this appointment and the S2 sample of the chamber was taken. The CFU was counted in the same way as stated for the S1 sample. The CFU/ml values were obtained from the microbiologist, tabulated, and sent for statistical analysis. The data were analyzed with IBM SPSS 20.0 (IBM Corp., Armonk, NY, USA)for windows statistical software. Statistical analysis was done with a one-way analysis of variance and Tukey's post hoc test [Flow diagram 1].
| Results|| |
The present clinical study was carried out clinically to microbiologically evaluate cotton, PTFE tape, and foam as an endodontic spacer material in permanent premolars and molars. According to the values [Graph 1], the P value (P < 0.05) shows a statistically significant difference in all the three groups concerning their baseline and after 7-day mean values. When an intergroup comparison was done [Table 1], the mean difference between the cotton and PTFE tape group showed a statistically significant difference (P < 0.05). Furthermore, the comparison between PTFE tape and foam group reported no statistically significant difference suggesting that the clinical performance of PTFE tape and foam as an endodontic spacer was better than cotton.
| Discussion|| |
The main principles of endodontic treatment should be aimed at eliminating all bacteria from the tooth and then attempting to maintain the tooth in this disinfected state by preventing any further ingress of bacteria during and after treatment. Endodontic spacers are the materials that are placed beneath the temporary restorations in between the endodontic appointments or between endodontic and restorative appointments. Previous research has demonstrated that cotton was the most commonly used spacer beneath temporary restorations. However, cotton spacers have their disadvantages as they could lead to the decreased thickness of the temporary restorative materials, which ideally should be between 3 and 4 mm. Furthermore, there is concern about the organic and fibrous nature of cotton that might promote wicking and bacterial uptake.,
The use of cotton pellets is therefore controversial, and many practitioners have tried other materials as spacers, such as foam pellets and PTFE tape. PTFE has been gaining popularity as an endodontic spacer since it possesses many of the advantages of cotton spacers and may have the potential to overcome the disadvantages of unsatisfactory stiffness and the potential to allow microbial growth. PTFE is relatively inert; as such it is capable of resistance to solvents and acids, therefore will not degrade when used with dental etchants. PTFE has a high melt viscosity (approximately six times that of most fluoropolymers) which allows the tape to be sterilized for dental purposes in an autoclave. In endodontics, PTFE has been investigated as a spacer material.
Prabhakar et al. (2018) conducted a study to evaluate PTFE tape as endodontic spacer material and to compare it with commonly used spacer material that is cotton, in primary teeth. It was concluded that PTFE tape performed better than cotton as endodontic spacer material.
Olsson et al. (2017) conducted a study to evaluate which spacer showed less bacterial leakage between endodontic treatments. Cotton and PTFE spacers were collected after a 2 to 4 weeks' time interval between the first and second appointments. Based on the results of this study, the use of PTFE is strongly recommended over cotton as an endodontic spacer material.
Many practitioners have tried other materials such as foam pellets as spacers. These endodontic sponges serve as chairside storage and mechanical cleaning aid of root canal instruments (Hubbard et al. 1975, Rutala et al. 1998, Chu et al. 1999, Linsuwanont et al. 2004, Parashos et al. 2004, Popovic et al. 2010). Rotary NiTi endodontic instruments can be sterilized effectively with or without the removal of rubber stoppers when inserted into endodontic sponges. However, its use as an endodontic spacer has been only mentioned and not explored in any clinical study.
The current study microbiologically evaluates the cotton, PTFE tape, and foam as an endodontic spacer. The results of the study demonstrated that the mean baseline and after 7-day values for all three groups showed a statistically significant difference. Thus, it can be stated that there was an increase in the microbial load over the period of 7 days in all three groups. On intergroup comparison, it was found that the mean difference values for cotton and PTFE tape showed statistical significance, thus, PTFE tape can be used as a replacement for cotton as an endodontic spacer. Furthermore, there was no statistical difference between PTFE tape and the foam group which suggests that foam can be considered for use, and cotton performed the worst among the three. The reason for the increased microbial load in the cotton group could be that the cotton fibers were exposed to the oral environment and had a tendency to wick potential contaminants into the pulp chamber. It could also be due to the tendency of cotton to distort under masticatory forces. If the spacer is unable to maintain the integrity of the space it is holding, the overlying temporary material could sink and the marginal seal could be compromised. PTFE, on the other hand, is stiffer than cotton and when condensed well, it shrinks less than cotton under masticatory forces. Another important factor to consider is that PTFE and foam do not adhere to the walls of the access cavity and can be easily placed and removed, in contrast to cotton, which does tend to leave fibers behind and is more difficult to remove. The limitation of the study includes a smaller sample size, and further studies for evaluation of foam as an endodontic spacer are required. The null hypothesis was rejected.
| Conclusions|| |
Within the limitations of the current study, it can be stated that the PTFE and foam group performed better, and hence, the use of PTFE tape and foam is recommended over cotton as an endodontic spacer material.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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