Influence of a colloidal silver dioxide solution on the edge adjustment of the mineral aggregate trioxide cement for closure of perforation communications in vitro

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Endodontic perforation is a pathological, mechanically created communication between the root canal system and the supporting apparatus of the tooth [1].According to statistics, endodontic treatment of every 8th tooth can lead to iatrogenic pathological perforation, and further entail its removal. According to K.A. Narbekova et al. (2018) [2], the frequency of endodontic perforations is up to 12% of all complications in the treatment of pulpitis and periodontitis

Depressurization of the root canal system is accompanied by bacterial invasion in the zone of pathological communication, which entails the risk of resorption of the ligamentous apparatus and further leads to tooth loss.

In the future, this pathology contributes to the dysfunction of the dentoalveolar system and organs of the nasopharyngeal region as a whole, affecting the chewing function and causing psychological and physical discomfort to patients.

Chewing efficiency characterizes the degree of grinding, to which the food is brought by the dentition during the chewing function. With the loss of a tooth, the chewing efficiency of the dentition decreases, which over time can adversely affect both its functioning in particular and the health of the digestive system as a whole

Modern methods of treatment of the root canal system require the use of mineral trioxide aggregate cements. Until 1998, a perforated message was an indication for tooth extraction. At present, in modern dentistry, thanks to the improvement of dental materials, methods for closing perforations of the root canals of the teeth have been developed and introduced into clinical practice.

Mineral trioxide aggregate filling materials, according to manufacturers, provide reliable sealing of the perforated message due to low solubility, volumetric expansion during curing and high biological activity that promotes tissue regeneration.

All preparations based on MTA have an effect on the formation of tertiary and replacement dentin due to the effect of calcium hydroxide on odontoblasts. The material also has an odontotropic effect by releasing bioactive molecules, which makes its use highly effective in order to preserve the viability of the pulp and stimulate reparative dentinogenesis [3].

MTA cements are able to harden and gain strength in a humid environment, providing a more reliable sealing of the root canal compared to other materials intended for this purpose. It has been proven that materials based on MTA have not only bacteriostatic properties, but also potentially bactericidal properties, due to the release hydroxide ions, which ensures the maintenance of high pH values ​​for a long period, and the formation of a mineralized intermediate layer at the material-tooth tissue interface provides unfavorable conditions for the survival of bacteria [4].

A feature of MTA cements is their complete biocompatibility with periradicular tissues. This material provides reliable sealing of the apical opening of the root canal. Such unique cement properties as biocompatibility with human bone tissue and the ability to harden in a humid environment make it possible to more successfully and reliably deal with chronic stomatogenic foci of infection and sensitization of the body, the presence of which negatively affects the somatic status patient.

Currently, the most common materials on the Russian dental market are Rutdent (TehnoDent), Trioxident (VladMiVa) and Canal MTA (OmegaDent). The chemical composition determines the physicochemical properties of these materials. The material for eliminating root canal defects "Canal MTA", according to TU 9391-042-49908538-2012 RU No. RZ 2013/1373 of 01/23/2014, consists of a mixture of hydrophilic particles: mainly - tricalcium silicate, as well as calcium-containing compounds of iron and aluminum

The material "Canal MTA" has a high sealing ability, which practically does not change when blood enters. The material has a high pH=12, as a result of which it has a pronounced bactericidal effect. Dental water-soluble material for retrograde filling and correction of defects in the root canals of teeth "Trioxident", according to TU 9193-100-45814830-2004, contains oxides of calcium, silicon, aluminum. When interacting with water, the material forms a plastic mass, which actively releases calcium hydroxide (pH=12.8), gradually hardens, turning into an insoluble calcium hydroaluminosilicate during the reaction.

The calcium hydroxide particles then compact the mass of the formed calcium silicate, increasing the mechanical strength of the resulting cement. Calcium hydroxide stimulates the processes of apexogenesis and osteogenesis in the treatment of teeth with unformed roots, stops bone tissue resorption, stimulates the formation of a dentin bridge when pulp is covered, and has bactericidal properties.

Purpose: To conduct a comparative experimental study of water sorption and the preservation of the marginal fit to the tooth tissues in the area of ​​perforations of fillings from MTA cements mixed in the conventional way with distilled water and a colloidal solution of silver dioxide. Methods: Study design. Observational study. Single-center study. Prospective study, laboratory. Selective study. Controlled. The control group - samples of MTA material mixed with distilled water. The proportions are observed according to the recommendations of the manufacturer. Unblinded study, laboratory. Non-randomized.

During the study, 12 samples were made in the form of "tablets" with a height of 5 mm and a diameter of 6 mm of the following leading Russian representatives: Rutdent (TehnoDent), Trioxident (Vladmiva) and Canal MTA (OmegaDent), a total of 36 samples Samples Nos. 1–6 Trioxident (VladMiVa), Nos. 7–12 Channel MTA (OmegaDent), Nos. 13–18 Rootdent (TehnoDent) were mixed with distilled water, according to the manufacturer’s instructions. Samples No. Nos. 19–24 Trioxident (VladMiVa), Nos. 25–30 Channel MTA (OmegaDent), Nos. 31–36 Rootdent (TehnoDent) were mixed with a colloidal solution of silver in the same proportion as recommended by the manufacturer for distilled water. The samples were weighed using an HR-202i laboratory analytical balance.

Weighed samples were placed in an HHD7 LED automatic incubator for chicken and quail eggs, in which an optimal mode was created that simulates the conditions of the oral cavity (t = 37°C, humidity 99%, irrigation was performed with artificial saliva (PARO) every 2 hours) (Fig. 2). After 5 days, the dental materials of the MTA group were re-weighed on an HR-202i balance. Based on the difference between the results of the repeated and initial weighing, the relative content of sorbed water in the samples was determined, which was expressed as a percentage.

Further, the study was continued with biological material - teeth previously removed for medical reasons. Endodontic treatment of 60 teeth was carried out: preparation of hard tissues of the tooth, trepanation of the tooth cavity, creation of endodontic access, identification of the orifices of the root canals, passage of the canals and determination of the working length, mechanical and drug treatment of the root canals, expansion and smoothing of the walls. Iatrogenic perforations of the root walls formed. The teeth were divided into two groups. For the teeth of the first group of MTA, the material for closing the perforations was kneaded with distilled water, for the teeth of the second group, with a colloidal solution of silver.

Perforations in the teeth of the 1st group of subgroup No. 1 (10 teeth) were closed with the Rootdent material (TehnoDent), in the teeth of subgroup No. 2 (10 teeth) - with Trioxident (VladMiVa), in the teeth of subgroup No. 3 (10 teeth) - material "Canal MTA" (OmegaDent). All materials in this group were mixed with distilled water. Perforations in the teeth of the 2nd group of subgroup No. 4 (10 teeth) were covered with the material "Rootdent" (TehnoDent), in the teeth of subgroup No. 5 (10 teeth) - with "Trioxident" (VladMiVa) , in the teeth of subgroup No. 6 (10 teeth) were covered with the material "MTA Channel" (OmegaDent). All materials in this group were mixed with colloidal silver solution.

The stage of root canal obturation was performed by introducing Thermafil obturators, using an AN+ sealer. Then, all teeth were placed in an HHD7 LED automatic incubator, in which an optimal mode was created that simulates the conditions of the oral cavity (t = 37 ° C, humidity 99%). The samples were in artificial saliva.

After 2 months of exposure of teeth in a humid environment, the safety / violations of the marginal fit in the area of ​​perforations of fillings from the materials "Rootdent" (TehnoDent), "Trioxident" (VladMiVa) and "Canal MTA" (OmegaDent) were studied using a Levenhuk 720B binocular microscope. .Compliance CriteriaIn the study, the criteria were:

Compliance criteria In the study, the criteria were: In the study, the criteria were: Possibility of complete mechanical processing of root canals in the studied teeth. The factor of root canal patency was taken into account, based on their anatomical features. Iatrogenic perforations were made in one group - in the orifice, middle and apical thirds - 10 pieces each. Materials certified in the Russian Federation were used in the study. teeth.

Conditions of the study The study was conducted on the basis of the Federal State Budget Military Educational Institution of Higher Education “Military Medical Academy named after S.M. Kirov" at the departments of general dentistry and general chemistry. At an air temperature of 37°C and a relative humidity of 99% (imitation of oral conditions).

Duration of the study Planned study duration - 1 year. In fact, the study was conducted for 1 year. Description of the medical intervention All studies were conducted in vitro. Main outcome of the study The water adsorption rate was found in MTA samples mixed with distilled water and colloidal silver solution. Additional study outcomes

Analysis in subgroups Violation of the marginal fit of the material Trioxident to the tooth tissues was established in 3 (15.0±6.6%) cases, including 2 (20.0±13.3%) cases when kneading with distilled water and 1 (10, 0 ± 10.0%) the case when the material was mixed in a colloidal solution of silver dioxide (p> 0.05). Violation of the marginal fit of the material MTA channel to the tooth tissues was found in 4 (20.0 ± 7.4%) cases, including including 3 (30.0±15.3%) cases when mixing with distilled water and 1 (10.0±10.0%) case when mixing the material with a colloidal solution of silver dioxide (p>0.05).

Violation of the marginal fit of the Rutdent material to the tooth tissues was established in 2 (10.0±5.6%) cases, including both, i.e. In 2 (20.0±13.3%) cases when mixing on distilled water, when mixing the material on a colloidal solution of silver dioxide, no cases of violation of the marginal fit were detected (p<0.05) (Table 2). Methods for recording outcomes Description of the results of microscopy Method weighing on a laboratory analytical balance HR-202iEthical review

Extract from protocol no. 265 of the regular meeting of the independent Ethics Committee at the Military Medical Academy named after S.M. Kirov dated June 28, 2022. Decided: To approve the competition work of Kozlova I.V. "Laboratory studies of materials for closing perforations after endodontic treatment." Statistical analysis

The average relative content of sorbed water in the samples for each material was calculated, which was expressed as a percentage, the error of the arithmetic mean. RESULTS Research objects (participants) Extracted for medical reasons, natural teeth. Main results of the study ) and is presented in Table. 1. It has been established that Kanal MTA was in the first place in terms of the relative content of sorbed water, when mixed with distilled water it amounted to 13.20±0.11%, while using a colloidal solution of silver dioxide - 12.25±0.08% .

The second place in terms of the relative content of sorbed water was taken by the Trioxident material (11.23±0.06% and 10.88±0.07%, respectively), and the most favorable results, which differ significantly from the first two (p<0.05), demonstrated the Rutdent material (7.68 ± 0.12% and 6.17 ± 0.09%, respectively). on distilled water (p>0.05).

Photos of studies on extracted teeth are shown in fig. 1–6. In total, out of 60 natural teeth with perforations sealed with MTA cements, microscopic examination revealed a violation of the marginal fit of the material to the tooth tissues in 9 cases (15%). ±6.6%) cases, including 2 (20.0±13.3%) cases when mixing with distilled water and 1 (10.0±10.0%) case when mixing the material with a colloidal solution of silver dioxide ( p>0.05).

Violation of the marginal fit of the MTA channel material to the tooth tissues was found in 4 (20.0±7.4%) cases, including 3 (30.0±15.3%) cases when kneading with distilled water and 1 (10.0 ±10.0%) the case when the material was mixed in a colloidal solution of silver dioxide (p>0.05). Violation of the marginal fit of the Rutdent material to the tooth tissues was established in 2 (10.0±5.6%) cases, including including both, i.e. In 2 (20.0 ± 13.3%) cases, when mixing with distilled water, when mixing the material with a colloidal solution of silver dioxide, no cases of violation of the marginal fit were detected (p<0.05) (Table 2).

DISCUSSION

Summary of the main result of the study The relative water content, directly related to the porosity of the material, in the case of preparing samples in the presence of nanosized silver particles is less than with standard mixing, i.e. the material is more monolithic. Obviously, nanosized silver particles affect the mechanism of formation of the material matrix, making it more monolithic and, therefore, stronger.

In the experiment on the study of the relative water content, the most favorable results, significantly different from the Kanal MTA and Trioxident materials (p<0.05), were demonstrated by the Rutdent material (7.68±0.12% and 6.17±0.09%, respectively) .The use of a colloidal solution of silver dioxide for mixing materials contributed to a tendency to reduce the relative content of sorbed water compared to samples mixed with distilled water (p>0.05).

After 2 months of keeping 60 teeth with filled perforations in conditions imitating the oral cavity, a violation of the marginal fit to the walls of the teeth of MTA cements mixed with distilled water was recorded in 15% of cases, significant differences between the materials used in this indicator were not revealed. A significant difference was established in the total number of cases of violation of the marginal fit between the 1st group (kneading the powder in distilled water), which amounted to 7 (23.3±7.9%), and the 2nd group (kneading the powder in a colloidal solution of silver dioxide) – 2 (6.7±4.6%), (p<0.05).

The most favorable result was demonstrated by the Rutdent material: 2 (20.0±13.3%) cases of violation of the marginal fit were noted with the generally accepted mixing of the material in distilled water, and when using a colloidal solution of silver dioxide, none were detected (0%), (p<0 .05). However, no significant differences were found between the subgroups in which different materials were used (p>0.05). As a result of the study, a method for manufacturing mineral trioxide aggregate cement for closing perforation messages during endodontic treatment was developed (application for invention, priority certificate No. 2022121481 dated 08/05/2022).

Discussion of the main result of the studyAs a result of a study in a humid environment of natural teeth with perforations filled with materials "Rootdent" (TehnoDent), "Trioxident" (VladMiVa) and "Canal MTA" (OmegaDent), it was found that mixing MTA cements in a colloidal solution of silver contributes to a better preservation of the marginal fit of the material to the tooth wall in the area of ​​perforation. Limitations of the study

CONCLUSIONS The studies on the modernization of the chemical composition demonstrate a new approach to improving the chemical structure and ordering of the particles of mineral trioxide aggregate cements, open up new possibilities for using this material even in the most difficult clinical situations, due to the monolithic and durable structure, uniform distribution and better adhesion to the walls of the root canal.

The results obtained allow us to recommend to dentists a new method of closing the perforations of the root canal of the tooth with a more predictable successful result. A new way to effectively close the perforation of the root canal of the tooth, can reduce the likelihood of purulent-inflammatory complications and the risk of developing chronic odontogenic foci of infection.

DDITIONAL INFORMATION SOURCE OF FUNDING. The authors declare no external funding for the study and publication. Funding source. This study was not supported by any external sources of funding.

CONFLICT OF INTEREST.

The authors declare no apparent or potential conflicts of interest related to the research and publication of this article. Competing interests. The authors declare that they have no competing interests.

I.V. Kozlova - laboratory research, collection and analysis of literary sources.

Yu.B. Vorobieva - collection and analysis of literary sources, preparation and writing of the text of the article, statistical processing of the research results.

V.A.Zheleznyak - writing the text, editing the article.

A.M. Kovalevsky - writing the text, editing the article. All authors confirm that their authorship complies with the international ICMJE criteria (all authors made a significant contribution to the development of the concept, research and preparation of the article, read and approved the final version before publication).

 We express our gratitude to the Head of the Department of General Dentistry - Zheleznyak Vladimir Andreevich for providing departmental resources in the framework of scientific activities. We express our gratitude to the Head of the Department of General Chemistry - Khimich Nikolay Nikolaevich for a significant contribution to the development of a scientific idea.

 

 

About the authors

Ivanna V. Kozlova

Kirov Military Medical Academy

Email: kozlova.ivanna@list.ru
ORCID iD: 0000-0001-8143-3518
SPIN-code: 1659-4870

Student

Russian Federation, 37 Academician Lebedeva street, 194044, Saint Petersburg

Alexander M. Kovalevsky

Kirov Military Medical Academy

Email: endy_taker@mail.ru
ORCID iD: 0000-0002-0772-0663
SPIN-code: 6899-4345

MD, Doc. Sci. (Med.), Assistant Professor

Russian Federation, 37 Academician Lebedeva street, 194044, Saint Petersburg

Julia B. Vorobieva

Kirov Military Medical Academy

Email: doctor32@bk.ru
ORCID iD: 0000-0003-0394-7868
SPIN-code: 9690-1182

MD, Cand. Sci. (Med.), Assistant Professor

Russian Federation, 37 Academician Lebedeva street, 194044, Saint Petersburg

Vladimir A. Zheleznyak

Kirov Military Medical Academy

Author for correspondence.
Email: zhva73@yandex.ru
ORCID iD: 0000-0002-6597-4450
SPIN-code: 3895-3730

MD, Cand. Sci. (Med.)

Russian Federation, 37 Academician Lebedeva street, 194044, Saint Petersburg

References

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