Year : 2019 | Volume
: 9 | Issue : 5 | Page : 427--433
Oxygen alkaline dental’s cleaners from tooth plaque, food debris, stains of blood, and pus: A narrative review of the history of inventions
Aleksandr Urakov1, Natalia Urakova2, Alexey Reshetnikov3,
1 Department of General and Clinical Pharmacology, Izhevsk State Medical Academy, Izhevsk, Russia; Department of Synthesis and Modeling of Technological Processes, Udmurt Federal Research Center of the Ural Branch of the Russian Academy of Sciences, Izhevsk, Russia
2 Department of Obstetrics and Gynecology, Izhevsk State Medical Academy, Izhevsk, Russia
3 Izhevsk Dental Clinic “ReSto”, Izhevsk, Russia
Prof. Aleksandr Urakov
Metallistov str., 33–9. Izhevsk 426054.
Objective: This review shows the history of inventions of devices, hygiene products, and methods of dissolution and removal of pus, sulfur plugs, blood crusts, and plaque. Material and Methods: The search for inventions was carried out in the databases, such as Google Patent, Google Scholar, Scopus, and PubMed. The key words used in this search were as follows: toothbrushes, toothpicks, toothpastes, plaque, cleaning products for teeth and dentures, teeth whiteners and dentures, bleach bruises and blood stains, pus, sulfur plugs, and pus solvents. A total of 24 inventions were evaluated for review. Results: In recent years, hygiene products that quickly dissolve and bleach pus, sulfur plugs, blood stains, and plaque because of alkaline saponification of protein–lipid complexes and cold boiling inside the biological masses have been invented. Such an action has a heated above 37°C supersaturated sodium bicarbonate solutions containing hydrogen peroxide in moderate concentrations and gaseous oxygen under excessive pressure. Cold boiling inside the dense biological masses occurs under the action of catalase and/or due to the normalization of internal pressure in the solution. Conclusion: Alkalinity, hyperthermia, and hyperoxygenation of solutions with high internal pressure optimize whitening of teeth and dentures because of alkaline saponification and cold boiling.
|How to cite this article:|
Urakov A, Urakova N, Reshetnikov A. Oxygen alkaline dental’s cleaners from tooth plaque, food debris, stains of blood, and pus: A narrative review of the history of inventions.J Int Soc Prevent Communit Dent 2019;9:427-433
|How to cite this URL:|
Urakov A, Urakova N, Reshetnikov A. Oxygen alkaline dental’s cleaners from tooth plaque, food debris, stains of blood, and pus: A narrative review of the history of inventions. J Int Soc Prevent Communit Dent [serial online] 2019 [cited 2019 Dec 13 ];9:427-433
Available from: http://www.jispcd.org/text.asp?2019/9/5/427/268333
During the latter half of the twentieth century, people in all countries in the world achieved impressive progress in health that leads to a significant increase in life expectancy, which has increased the growth in the number and proportion of older persons in society. This also caused an increase in the service life of teeth and dental structures, which increased the proportion of worn and painted hard tissues of the mouth in their total volume. With increasing service of teeth and dentures, they are more and more covered with plaque, food residues, blood stains, and pus. At the same time, known means of personal hygiene of the oral cavity are not able to recover urgently to restore the original whiteness and purity of the surfaces of the teeth and dental structures. Therefore, in the elderly, regardless of their use of personal hygiene products, the surface of the teeth and dental structures is contaminated. This worsens their appearance, causes bad breath, and contributes to the development of stomatitis and periodontal disease., The existing patent and scientific literature emphasizes that the condition of teeth and dental constructions can be improved by improving the quality of personal oral hygiene. Among personal hygiene products, toothbrushes, toothpastes, toothpicks, chewing stick, and oral irrigators are most often used., These hygiene products, methods of their application, and devices are regularly upgraded and improved. All of them are aimed at emergency mechanical cleaning of the surface of teeth, dentures, and other dental structures from food pollutants. However, their effectiveness is still not high enough, especially in the elder.,
At the same time, the successes achieved in the field of physical–chemical pharmacology with emergency dissolution of thick pus, sulfur plugs, and blood clot, give hope for the presence of physical–chemical reserves of dissolution of plaque and food residues in the oral cavity. The fact is that in the field of hygienic dentistry little attention was paid to physical and chemical factors of local interaction of hygienic solutions in the oral cavity. In particular, there are no systematic studies devoted to the study of such factors of local interaction as alkaline, osmotic, temperature activity, and the presence of oxygen gas at excessive pressure in the action of hygiene products on dental plaque.
It has been proven that the high-precision local mechanical and hydrodynamic effects, liquid form, the presence of friction properties, local hyperthermia, the increase of the local pH above 7.0 (local hyper alkalinity), increasing the specific gravity, and oxygen gas saturation under high pressure (hyperoxygenation) are the most important physical–chemical factors for effective dissolution and removal of thick pus, cerumen, and blood clots.,, However, the importance of these physical and chemical factors for bleaching blood stains, pus, and removing plaque and other contaminants from the surface of teeth and dentures in the home is not fully understood. There is not enough information about the achievements in this area in specialists and in the adult population, which hinders the progress and optimization of oral hygiene. At the same time, it is known that oral hygiene skills are formed under the influence of public opinion, dentists, and family members.,
The aim of this study was to show the prospects of giving certain physical and chemical properties to various dental products to increase the speed and efficiency of plaque removal by analogy with the inventions that provide rapid dissolution and removal of thick pus, sulfur plugs, and blood stains.
Material and Methods
A thorough search for patents for inventions and information on new devices, drugs, and methods for dissolving and removing dense biological masses using certain physical and chemical factors of local interaction was carried out from 1999 to 30 January 2019, and was conducted using the databases, such as Google Patent, Google Scholar, Scopus, and PubMed. In addition, we studied the references and conducted a citation search. A systematic review was conducted in accordance with the quality standards described in the AMSTAR measurement tool and the PRISMA 2009 checklist. The search strategy was based on the PICO model., Two coauthors independently selected, evaluated and extracted data. The inconsistencies in the reviews were resolved by consensus. The flowchart for selecting articles was a spiral in which each spiral turn was an iteration., The key words used in this search were as follows
toothbrushes, toothpicks, dental plaque, toothpaste, solution for mouthwash, tool for cleaning teeth and dentures, tooth whiteners, bleach tooth, bleach dentures, bleach blood, bleach bruising, whitening products, whitening methods of blood stains, and solvents of thick pus. The inclusion criteria of the study were limited to medicines, as well as devices and methods of their use for oral hygiene, providing urgent discoloration and removal of blood stains, thick pus, food residues, and plaque because of physical–chemical properties. The exclusion criteria of the study were the absence of inventions intended for urgent discoloration, dissolution, and removal of dense biological masses, including plaque. The risk of individual bias in judgments was reduced by relying on the essence of the invention as a generally accepted criterion of novelty. A total of 27,150 sources of information were studied, in which only 24 inventions were evaluated for review.
It has been shown that the degree of purity in the oral cavity depends on many factors, such as the age and general health of the person, the compliance with the rules of personal hygiene, the care of health, the state of the chewing apparatus, the type and quality of food, and the devices and means of oral hygiene., The latter factors become most important in old age and especially in the presence of dentures, as older people often brush their teeth not very carefully due to the risk of injury and breakages of dentures, reduced dexterity, visual impairment, and physical limitations associated with conditions such as stroke, Parkinson’s disease, or severe arthritis.,
Unfortunately, the problem of individual cleaning of teeth from plaque is still not finally resolved. It has been shown that toothpicks, toothbrushes, and toothpastes are widely used for this purpose, and in recent years oral irrigators have been used for this purpose. However, no known solution yet provides at home the achievement of absolute purity in the oral cavity.
It has been shown that similar hygienic problems have been successfully solved in purulent peritonitis, pancreonecrosis, pleurisy, otitis media, and thrombosis of vascular catheters and veins, in bruises, hematomas, and bleeding because of specially developed solutions that provide emergency dissolution of thick pus, ear plugs, blood clots, blood stains, and bloody crusts due to special physical and chemical properties.
Physical–chemical properties solvents of thick pus
Numerous studies from around the world have shown that thick pus, sulfur plugs, blood clots, and dry blood crusts can be rapidly dissolved and discolored by solutions of hydrogen peroxide, if the solutions will have special physical and chemical properties.,,,
It can be argued now that the development of medical alkaline cleaners (solvents of dense biological masses) and new medical technologies for the use of drugs began with the invention of original pus solvents and ways to use them to remove pus in purulent peritonitis, purulent pleural empyema, and infected pancreonecrosis.,, Therefore, in 2008, patents for the following inventions were granted in Russia: “Hyper-gassed and hyper-osmotic antiseptic mixture” (RU Patent 2331441) and the “Method of peritoneal dialysis using a gasified solution” (RU Patent 2336833). For the first time, it was proposed to use an “aqueous antiseptic solution comprising 2.7%–3.3% hydrogen peroxide, 0.9%–10.0% sodium chloride, and gas of carbon dioxide at an overpressure of 0.2 ATM at 8°C.”
The novelty was that the solution at local interaction with pus literally “blows up” a monolithic piece of thick pus. The reason for this local effect was the process of cold boiling. The fact is that gas bubbles appeared in the solution not only around the pus but also inside the purulent mass. Therefore, pieces of porous purulent mass floated up in the solution. All this accelerated and increased the efficiency of removing the thick pus outwards.
Then in 2009 the patent for softening agent for thick and viscous pus was granted. This drug was the first alkaline bleach thick biological masses, because it was first proposed a combination of hydrogen peroxide and sodium bicarbonate: “the proposed tool is an aqueous antiseptic solution containing 2.7%–3.3% hydrogen peroxide and 5.0%–10.0% sodium bicarbonate” (RU Patent 2360685).
The new formulation provides the solution with a pH of 8.5. In turn, the optimal alkaline properties provide chemical saponification of the purulent mass at the boundary of the media separation and diffusion penetration of the solution into the purulent mass without damaging the living tissues surrounding the purulent masses in the body cavity. The presence of 3 ± 0.3% peroxide provides, as a result of the catalase reaction, the interstitial release of molecular oxygen, the formation of gas bubbles in the thickness of liquefied pus, the destruction of the “monolithic” structure of the purulent mass, the adhesion of bubbles with liquefied and pulverized particles of pus, the separation of these particles from the bulk of pus, their movement upward (ascent), and mixing the solution with liquefied and crushed particles of pus.
In 2012, a patent was granted for the invention “Method and means for removal of sulfur plug” (RU Patent 2468776). The essence of this invention is that a drug heated to 42°C is introduced into the sulfur plug with help of injections, which is an aqueous solution comprising 0.3%–0.5% hydrogen peroxide and 1.7%–2.3% sodium bicarbonate. The solution was injected inside sulfur plug up to its complete infiltration. The novelty of this method lies in the high accuracy, which provides injection of the drug solution directly into the sulfur plug. In addition, the novelty is a formulation that provides a moderate “cold boiling” of the solution in the presence of the enzyme catalase and eliminates a powerful explosion inside the outer ear cavity.
At the same time, in 2012 a patent was granted for the invention “Means for sanation of fistulas in infected pancreatic necrosis” (RU Patent 2455010). The essence of this tool is that it has a pH of 6.7–6.9, has hyperosmotic activity within 340–370 mosmol/l of water, and has a significant buffer capacity. The introduction of the proposed solution into the cavity of the purulent focus eliminates the alkalinity and aggressiveness of the juice flowing from the pancreas to the purulent inflammatory focus in pancreonecrosis.
Physical–chemical properties of blood bleaches
Almost in parallel with the development of a group of drugs, diluting thick pus and sulfur plugs, it was the development of a group of funds intended for dissolving blood clots, drying crusts of blood, and bleaching spots and traces of blood.,, Thus, in 2009, a patent was granted for the first invented “Method of express removal of blood stains from clothing” (RU Patent 2371532), in which it was proposed to use an aqueous solution with a pH of > 7.0 at a certain osmotic activity and a certain temperature ranging from 26 to 42°C. It was shown that because of the alkaline, temperature, and osmotic activity, this solution allows to urgently remove blood stains due to the hemolysis of red blood cells.
In 2015, a patent was granted for the first drug intended for urgent discoloration of blood traces by intradermal or subcutaneous injections of a solution containing a combination of hydrogen peroxide and sodium bicarbonate. This drug was called “Bleach bruising” (RU Patent 2539380). The novelty of this tool was the high speed of discoloration of blood traces inside the skin. This effect was provided by the injection of a solution of the drug-bleach of bruises inside the skin in the area of the bruise. Then in 2016, the patents were granted for “Bleaching agent” (RU Patent 2589682), “Agent for intradermal bruise whitening” (RU Patent 2573382), “Method of skin discoloration in the area of bruising” (RU Patent 2582215), and “Method for skin discoloration in bruising area” (RU Patent 2586278). The developed bleaching agents are aqueous solutions for injection, which contain 0.01%–0.03% hydrogen peroxide, 1.7% or 1.8% sodium bicarbonate, and 0.125%–0.250% lidocaine hydrochloride as the main ingredients. These funds are used heated from 37 to 42°C. Their injections are made inside the skin until the formation of the entire area of the bruise of a continuous drug infiltration of the skin with a kind of colorless lemon crust. After that, immediately begin to produce vibrational hyperthermal massaging of the skin in the infiltrated area until complete resorption of the infiltrate.
In 2017, the patents were granted for “Method for emergency bleaching and blood crust removal from skin in place of squeezed out acne” (RU Patent 2631593), “Means for intravital skin whitening near blue eyes” (RU Patent 2639485), and “Method for whitening of bruise under eye” (RU Patent 2639485). The essence of these inventions is that for discoloration of blood traces on the skin and inside the skin (with bruises), it is proposed to the skin in the “right” place to apply a swab moistened with a warm solution of hydrogen peroxide, sodium bicarbonate, and a local anesthetic that easily penetrates through intact skin. In other words, a technology has been developed to discolor blood traces in conditions that exclude skin piercing, with an injection needle, additional damage to blood vessels, interstitial bleeding, bleeding, bruising, inflammation, abscesses, and sepsis.
Almost at the same time and a little later, in 2016–2019, in addition to these inventions, a group of drugs and methods for discoloration of a portion of blood, as well as the skin and the nail plate in the field of hematoma was invented. Therefore, in 2018 a patent was granted for the invention of “Bleaching opener of dried blood for wrapping bandages adhered to a wound” (RU Patent 2653465). The developed drug comprised 0.75–1% hydrogen peroxide, 1.2% sodium bicarbonate, 0.5% lidocaine hydrochloride, and bidistilled water. The use of the invention provides optimal osmotic, alkaline, buffer, foam-forming, washing, anesthetic, and whitening activity solution needed when sanitizing wounds for effective and safe softening of the bandage, bloodless, and painless removal of it from the wound and whitening of the wound and skin around it in terms of surface anesthesia. At the same time, in 2018, a patent was granted for “Decolorant of blood” (RU Patent 2647371). The drug includes at temperature 42°C hydrogen peroxide - 3±0,3%, sodium bicarbonate––in an amount that ensures saturation of the fluid and the preservation of the sediment at a temperature of 42°C, water for injection––the rest. The drug was designed to remove of fresh and old blood spots on clothing, bloodstained bandages, cotton-gauze dressings, surgical gloves, tools, hair, skin, and mucous membranes in places of injuries, bruises, abrasions, and surgical incisions.
In 2017 and 2018, the patents were granted for the “Method for whitening of sore under nail” (RU Patent 2631592) and for the “Method for blue nail treatment” (RU Patent 2641386). In 2019, the patent was granted for the “Method of emergency bleaching of the skin hematoma under the eye” (RU Patent 2679334). The essence of these methods is that a solution of 3% hydrogen peroxide and 10% sodium bicarbonate at a temperature of 37–42°C is first introduced into the hematoma cavity in a volume that provides discoloration of the tissues, and then this solution is used outside as a compress.
Physical–chemical properties of bleaching cleaners of teeth and dentures
In 2017–2019, the purposeful giving of certain physical and chemical properties to devices and means used for removal of plaque from the surface of teeth and dental structures was started. At the same time, two patents were first obtained for inventions that radically changed the traditional design of the toothpick. The essence of the first invention is that it was proposed to produce a toothpick that is not in the form of an awl, and in the form of a shovel, whose bayonet has a width of 1–4 mm, and its surface is completely covered with a sponge with a thickness of not more than 1.5 mm. To the outer surface of the sponge on one plane of the bayonet is firmly glued cleaning layer made of a darker than the sponge, solid fine-grained abrasive material designed for cleaning highly contaminated surfaces. The invention was called “Toothpick in a fur coat” (RU Patent 2622676). Toothpick in a fur coat removes stains of household, food, and medicinal dyes from the surface of the teeth and installed dental structures.
The essence of the second invention is that it was proposed to perform a toothpick from white edible materials monolithic in the form of an elongated spatula. The fact that was invented disposable (edible) toothpick for astronauts (RU Patent 2672798).
Simultaneously with the modernization of toothpicks in 2017 was invented “Friction toothpaste” (RU Patent 2626669). The essence of this invention is that a solution of 9.5%–10% sodium bicarbonate and 0.5%–1.5% hydrogen peroxide in a ratio of 5/1 mass was mixed with crystalline sodium bicarbonate at a temperature of 25–26°C. The sodium bicarbonate powder (baking soda) comprised soft crystals of 0.05–0.20 mm in size, which did not dissolve in an aqueous solution of 9.5%–10% sodium bicarbonate and 0.5%–1.5% hydrogen peroxide at a temperature of 25–26°C. As a result, a thick paste is formed in which the soft crystals of sodium bicarbonate have abrasive, friction, adhesive, erasing, absorption, and adhesive activity against the rough and soft surface of the “tooth” dirt, but not against the smooth and hard surface of the tooth enamel and smooth surface of the gum mucosa. Moreover, a solution of 0.5%–1.5% hydrogen peroxide and 9.5%–10% sodium bicarbonate softens and dissolves plaque, food residues, and blood clots, covering the tooth surface in the open areas and in the “deaf” cavities and recesses (in particular, under the elements of dental fasteners such as braces). The dissolution of these biological masses is because of alkaline hydrolysis of proteins and saponification of fats. The process of destruction is “exploding” (in a cold “boiling”) the surface layer of plaque, pus, blood clot, and other biological masses, as it occurs at the boundary of the separation of interacting media. The mechanical process involves scratching the treated surface with sodium bicarbonate crystals. Scratching occurs under the influence of the applied external force of pressure and due to the presence of the claimed means of friction activity.
On the contrary, in order to reduce the local physical and chemical aggressiveness of solutions that are used for long-term irrigation of the oral cavity (e.g., in many hours of surgery or in intubation and resuscitation of patients), it was decided to replace the “active gases” in the water, such as oxygen and carbon dioxide, with an inert gas helium. So was invented “Aerated mouthwash” (RU Patent 2635992). According to the invention, in the mouthwash, including sodium chloride, sodium hydrogen phosphate, sodium dihydrogen phosphate, hydrogen peroxide, water, and gas to create an overpressure of 0.2 ATM at 8°C, helium is used as the gas and lysozyme as the antimicrobial component. This tool can be used for long-term sanitation of the oral cavity in intensive care patients, since such a drug excludes the development of bronchitis, pneumonia, caries, and local inflammation in the oral tract.
Finally, in 2018, a patent was granted for the invention “Bleaching cleanser of dentures” (RU Patent 2659952): “Invention consists in that the whitening cleanser of dentures is prepared on water for injection and it contains 2.0–10.0 wt% of sodium bicarbonate, 3 ± 0.3 wt% of hydrogen peroxide and oxygen gas at an overpressure of 0.2 ATM at 8°C. Agent is heated to a temperature of 37–42°C.” The claimed means provides cleaning, deodorization, bleaching, and disinfection of dentures and surgical instruments with traces of blood and pus because of hyperthermic softening, alkaline saponification, cavitation loosening, dissolution, and oxidative decolorization of various biological masses.
In recent years, such electrical devices as oral irrigators have been used to remove plaque from the surface of the teeth in the oral cavity. However, to date, the use of these devices does not provide fast and effective cleaning of all surfaces of teeth, dentures, and other dental structures. In our opinion, the low efficiency of irrigators is explained by the fact that these devices are still not equipped with special solutions.
Analysis of the recommended liquids showed that the known means do not have an internal overpressure and the “desired” temperature. Another disadvantage of the known means is that they do not provide an optimal local temperature when introducing funds with the help of an irrigator. The fact is that to remove plaque with the help of an irrigator, the working fluid is initially introduced into the irrigator tank, which currently does not heat this liquid, but cools it. Then the liquid continues to cool in other elements of the design of the irrigator. The fact is that all parts of the irrigator are at room temperature, so they all take heat from the solution. At the same time, the container is made without the function of a thermostat, and the inner surface of the container, pump, flexible hose and the tip of the irrigator is not covered with thermal insulation material. Because of this, the fluid gives up some of its heat to the parts of the irrigator in all the way of the flow from the tank to the mouth. In this regard, there is a progressive decrease in the temperature of the liquid. In particular, all the design details of the irrigator often have a room temperature in the range of 24–26°C. In addition, the irrigator emits a jet of liquid, which before falling to the surface of the teeth inside the mouth flies some part of its way through the air, which also has a temperature of about 26°C. At the same time, the jet of liquid is even more cooled because of cold air and evaporation of moisture in the air. Under these conditions, the liquid is poured into the container of the irrigator at a temperature of 37–42°C, and the liquid gets to the surface of the teeth and dental structures in the oral cavity at a temperature of 31–36°C, that is, the liquid is on the surface of the teeth cold.
Nevertheless, we believe that the irrigator can significantly speed up and improve the cleaning of teeth and dentures. A review of the known inventions showed that for this purpose it is necessary to pour into the reservoir of the irrigator specially developed solutions of alkaline bleach, which should be heated to a temperature that provides solutions with the “necessary” degree of hyperthermia on the treated surface, that is, with local interaction. Most likely, irrigation future irrigation fluid will be a variant of alkaline bleach. Most likely, it will be an aqueous solution that will include water for injection, 2.0%–10.0% sodium bicarbonate, 2.7%–3.3% hydrogen peroxide, and a gas under overpressure in several atmospheres. This irrigation liquid will be in a hermetically sealed container, and before pouring into the reservoir of the irrigator it will be heated above 43°C.
The proposed composition of the irrigation fluid will provide a very rapid softening, loosening of biological masses (plaque with fragments of saliva, blood, and pus) on the surface of the teeth and dental constructions, dissolution and whitening of plaque without coloring, and aggressive action on soft and hard tissues of the oral cavity and without burning.
Thus, giving an aqueous solution of certain physical and chemical properties changes its biological activity. In particular, because of hyperthermal, alkaline, oxidative activity, and gas saturation at excessive pressure, the solution turns into a means of liquefying and discoloring dense biological masses. Dissolving in water as ingredients of hydrogen peroxide, sodium bicarbonate, and oxygen gas under excessive pressure gives the solution the ability to urgently to dissolve and whiten pus, blood clots, spots and dry crusts of blood, and plaque.
The physical–chemical properties of liquid cleaners, such as alkalinity, hyperthermia, and hyper oxygenation under high pressure, play an important role in local dissolution, discoloration, plaque removal, blood, and pus stains and in teeth whitening, dentures, and other dental designs because of alkaline saponification and the formation of gas bubbles in cold boiling. This area of research requires the involvement of different specialists. However, physical–chemical oral hygiene is a realistic goal that can be achieved in the near future, and advances in this area can improve the aesthetic result, health and reduce the cost of dental care for people of all ages.
Limitations of study could have been present due to the inclusion only inventions based on physical and chemical factors of local interaction. In addition, the included inventions were pioneering and scanty in this field. These methodological considerations should be expanded in the future.
The following public domain resources were used in the search inventions: Google Patent, Google Scholar, Scopus, and PubMed.
We thank Anton Kasatkin and Tatiana Urakova for their criticism and constructive suggestions.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
|1||Razak PA, Richard KM, Thankachan RP, Hafiz KA, Kumar KN, Sameer KM. Geriatric oral health: A review article. J Int Oral Health 2014;6:110-6.|
|2||Peter S Essentials of Preventive a Community Dentistry. 2nd ed. New Delhi, India: Arya Medi Publishing House Pvt. Ltd; 2004.|
|3||World Health Organization. WHO Oral Health Country/Area Profile. Available from: https://www.who.int/oral_health/databases/malmo/en/. [Last accessed on 2019 Jul 8].|
|4||Schou L, Wright K. [Danish public awareness of general health and international perspectives]. Tandlaegebladet 1982;86:511-6.|
|5||Petersen PE, Holst D. Utilization of dental health services. In: Cohen L, Gift HC., editors. Disease Prevention and Oral Health Promotion. Copenhagen, Denmark: Munksgaard; 1995.|
|6||Wu CD, Darout IA, Skaug N. Chewing sticks: Timeless natural toothbrushes for oral cleansing. J Periodontal Res 2001;36:275-84.|
|7||Malik AS, Shaukat MS, Qureshi AA, Abdur R. Comparative effectiveness of chewing stick and toothbrush: A randomized clinical trial. N Am J Med Sci 2014;6:333-7.|
|8||Soini H, Routasalo P, Lauri S, Ainamo A. Oral and nutritional status in frail elderly. Spec Care Dent 2003;23:209-15.|
|9||Urakov AL. The change of physical-chemical factors of the local interaction with the human body as the basis for the creation of materials with new properties. Epitőanyag––J Silic Based Compos Mater 2015;67:2-6.|
|10||Urakov AL, Urakova NA, Gadelshina AA. New medicines: The bleachers of bruises, blue nails, hematomas, blood stains and bloody crusts. Australas Med J 2017;10:942-3.|
|11||Urakov A, Urakova N, Reshetnikov A, Kopylov M, Chernova L. Solvents of pus-medicines with physical-chemical aggressive action. IOP Conf Ser: J Phys: Conf Ser 2017;790:012033.|
|12||Shea BJ, Grimshaw JM, Wells GA, Boers M, Andersson N, Hamel C, et al. Development of AMSTAR: A measurement tool to assess the methodological quality of systematic reviews. BMC Med Res Methodol 2007;7:10.|
|13||Moher D, Liberati A, Tetzlaff J, Altman DG.; PRISMA Group. Preferred reporting items for systematic reviews and meta-analyses: The PRISMA statement. PLoS Med 2009;6:e1000097.|
|14||Miller SA, Forrest JL. Enhancing your practice through evidence-based decision making: PICO, learning how to ask good questions. J Evidence-Based Dent Pract 2001;1:136-41.|
|15||Eriksen MB, Frandsen TF. The impact of patient, intervention, comparison, outcome (PICO) as a search strategy tool on literature search quality: A systematic review. J Med Libr Assoc 2018;106:420-31.|
|16||Boehm B. Spiral development: Experience, principles, and refinements. Spiral Development Workshop. In: Wilfred J, Hansen J., editors. 2000. Available from: http://www.sei.cmu.edu/reports/00sr008.pdf. [Last accessed on 2000 Feb 9].|
|17||Alshamrani A, Bahattab A. A comparison between three SDLC models waterfall model, spiral model, and incremental/iterative model. Int J Comput Sci 2015;12:106-11.|
|18||Casula I, Bonfanti L, Ganda A, Anzaldi T, Marchesini E, Bianchi ME, et al. Eating and oral hygiene habits in a population of young adults: An observational study. Ital J Dent Med 2017;2:90-100.|
|19||Bizhang M, Schmidt I, Chun YP, Arnold WH, Zimmer S. Toothbrush abrasivity in a long-term simulation on human dentin depends on brushing mode and bristle arrangement. PLoS One 2017;12:e0172060.|
|20||Molenda MA, Sroa N, Campbell SM, Bechtel MA, Mitch Opremcak E. Peroxide as a novel treatment for ecchymoses. J Clin Aesthet Dermatol 2010;3:36-8.|
|21||Urakov AL, Urakova NA. Original means of hygiene for the prevention of postoperative adhesions, effective liquefy thick purulent masses of cerumen and lacrimal stones. Mod Probl Sci Educ 2013;1. Available from: https://www.science-education.ru/ru/article/view?id=7607. [Last accessed on 2019 Jan 30].|
|22||Urakov A, Urakova N, Chernova L. Possibility of dissolution and removal of thick pus due to the physical-chemical characteristics of the medicines. J Mater Sci Eng B. 2013;3:714-20.|
|23||Urakov AL, Nikityuk DB. Solvents of pus: New drugs for the treatment of purulent diseases. Adv Curr Nat Sci 2015;1:1096-01. Available from: https://www.natural-sciences.ru/en/article/view?id=35015. [Last accessed on 2019 Jan 30].|
|24||Urakov A, Urakova N, Kasatkin A, Chernova L. Physical-chemical aggressiveness of solutions of medicines as a factor in the rheology of the blood inside veins and catheters. J Chem Chem Eng 2014;8:61-5.|