A COOLANT AND IRRIGANT FOR USE IN DENTAL SURGERY

Abstract: This invention relates to an irrigant for use in dental surgical procedures, the irrigant comprising an electrolytically activated aqueous solution, characterised in having a pH of between 6.75 and 10 with microcidal as well as anti-oxidising, dispersing and surfactant properties, rendering the irrigant bio-compatible and non-corrosive. The invention further relates to the use of an irrigant in dental surgical procedures, a method for irrigating dental surgical procedures, and a coolant for dental surgical rotary instruments when used in dental surgical procedures, including procedures such as the surgical removal of teeth, the treatment of alveolar osteitis, periodontal surgical procedures involving alveolar bone and first stage implant treatment surgery.

Description: TITLE: A COOLANT AND IRRIGANT FOR USE IN DENTAL SURGERY INTRODUCTION AND BACKGROUND TO THE INVENTION This invention relates to a coolant and irrigant for use in periodontal and surgical procedures involving alveolar bone, in surgical removal of teeth, during first stage implant surgery and in the treatment of post-extraction alveolar osteitis, as well as to a method for such surgical procedures, using such coolant and irrigant. Simple extraction is the preferred, easy method of removal of teeth. In certain cases, such as impacted teeth, fractured teeth, or ankylosed teeth this is not possible and it is then necessary to surgically remove these teeth. Surgery includes the steps of the incision of the periodontal tissues and periosteum; the reflection of a full thickness flap (of periodontium and periosteum); the removal of the overlying bone by means of motor or turbine driven rotary instruments; and the elevating of the tooth or root. The process is completed with the appositioning and suturing of the soft tissues. This procedure is typically followed by intense pain and swelling. The pain and swelling quite often lead to many days of bed rest and loss of productivity. One of the most common complications following the extraction of teeth is the infection of the tooth socket, commonly referred to as "dry socket". This condition is also known as alveolar osteitis, alveolitis sicca dolorosa, alveolalgia, postoperative osteϊtis or localised acute alveolar osteomyelitis. In this condition, the blood clot covering the alveoli disintegrates or disappears, with the subsequent release of a foul odour and severe pain, but no suppuration. The exact cause of "dry socket" is not known. The nature of the pain is quite severe and healing is relatively slow. There is no standard regimen of treatment for the condition. Many modalities and medicines have been suggested but there had been, until now, no satisfactory method or agent for treatment of post-extraction alveolar osteϊtis. In certain cases of advanced adult periodontitis surgical treatment is indicated. Such surgical treatment usually involves incision of the periodontal and mucosal tissues, reflection of a full thickness flap, resection and contouring of the alveolar bone, appositioning of the flap and suturing of the wound. Resection and contouring of the bone, when done by means of motor or turbine driven rotary instruments such as dental drills must always be accompanied by copious cooling and irrigation with sterile water or saline. Failure to do so will result in necrosis of bone, delaying healing. Even with proper cooling and irrigation, severe post-operative pain and slow healing is quite common after periodontal surgery. The use of osseo-integrated titanium implants in the jaws to support dental prostheses was pioneered by Branemark in Sweden. During the first stage of treatment, the bony mandible or maxilla is surgically exposed by incising the periodontium overlying the edentulous area and by reflecting a well-designed lap. The alveolar bone is then fenestrated in the exact position where the implant should be positioned by means of a sterile pilot drill driven by an electric motor, under sterile conditions. The pilot cavity is then reamed wider by means of another special bone-cutting drill. The surface area of this cavity is then counter sunk by means of a special countersinking drill. During the course of these drilling operations it is imperative that the drills and bone be cooled by a sterile, biocompatible solution. It is known that even the slightest increase in temperature or contamination by micro-organisms can lead to the eventual failure of the implant. After the completion of the drilling process the implant is inserted into the cavity, the periodontal tissues appositioned and sutured. The implants are normally left undisturbed for several months and surgically exposed during second stage treatment and the dental prostheses fitted. Any failure of implant supported prostheses imply very serious, dire, clinical, practical, ethical, financial and legal consequences. In normal dental practice, sterile water is used as coolant and irrigant. This is fed via an external line, a cumbersome device. Under no circumstances should tap water be used for cooling and irrigation and even more importantly, (prior to this invention) no coolant should be delivered by means of a water line integrated in the dental unit. It is known that most dental unit water lines are heavily contaminated by bacteria in the form of a biofilm. Tap water also contains micro-organisms. OBJECT OF THE INVENTION It is accordingly an object of this invention to provide a novel, relatively inexpensive and safe coolant and irrigant for use in dental surgery, including procedures such as the surgical removal of teeth, the treatment of alveolar osteitis, periodontal surgical procedures involving alveolar bone, first stage implant treatment surgery, as well as to provide a method for the surgicai removal of teeth, periodontal surgical procedures involving alveolar bone, the treatment of alveolar osteitis and first stage implant surgery, using such medium. The term "dental surgical procedures" for purposes of this specification shall be interpreted as to include the surgical removal of teeth, periodontal surgical procedures involving alveolar bone, first stage implant treatment surgery and the treatment of alveolar osteitis, and cognate terms shall have corresponding meanings. SUMMARY OF THE INVENTION According to a first aspect of the invention there is provided as an irrigant for use in dental surgical procedures, the irrigant comprising an electrolytically activated aqueous solution.. According to a second aspect of the invention there is provided the use of an aqueous solution as an irrigant in dental surgical procedures, the aqueous solution being characterised in that it is electrolytically activated. According to a third aspect of the invention there is provided a method for irrigating dental surgical procedures, the method including the step of irrigating the wound and the dental surgical instruments with an aqueous solution as hereinbefore defined. The method may comprise of the surgical removal of teeth, the method including the step of irrigating such teeth and associated alveolar bone and rotary instruments with such aqueous solution. Alternatively, the method may comprise of the treating of post-extraction alveolar osteϊtis, the method including the step of applying such aqueous solution to affected alveoli. Alternatively, the method may comprise of a periodontal surgical procedure involving alveolar bone, the method including the step of irrigating at least some of the rotary instruments and the alveolar bone with the aqueous solution. Alternatively, the method may comprise of first stage implant treatment surgery, the method including the step of irrigating at least some of the dental surgical instruments, the alveolar bone, the basal bone and the implant components with aqueous solution. According to a fourth aspect of the invention there is provided a coolant for dental surgical rotary instruments when used in dental surgical procedures, including procedures such as the surgical removal of teeth, the treatment of alveolar osteitis, periodontal surgical procedures involving alveolar bone and first stage implant treatment surgery, the coolant comprising an aqueous solution substantially as hereinbefore defined. The aqueous solution may consist of a mixture of an electrolytically activated, anion-containing solution and/or an electrolytically activated, cation-containing solution. The aqueous solution may consist of a mixture of the electrolytically activated, anion-containing solution and the electrolytically activated, cation-containing solution in the proportions and the state as produced by a suitable electrolytic device, capable of producing separate electrolytically activated, anion-containing and electrolytically activated, cation-containing solutions. The aqueous solution preferably consists of a mixture in a ratio of about 4 to 5 volumes of the electrolytically activated, anion-containing solution to about 1 volume of the electrolytically activated, cation-containing solution, when prepared from a n aqueous solution of a chloride or halide salt, and it would preferably consist of a mixture in a ratio of about 2 to 3 volumes of the electrolytically activated, anion-containing solution to about 1 volume of the electrolytically activated, cation-containing solution, when prepared from an aqueous solution of a bicarbonate or carbonate salt . The anion-containing solution and/or the cation-containing solution may be prepared by means of electrolysis of an aqueous solution of a salt. The salt may be sodium chloride or sodium bicarbonate, or sodium carbonate. In particular, it may be non-iodised sodium chloride or potassium chloride or the bicarbonate or carbonate salt of sodium or potassium. The anion-containing solution, produced in the anodic chamber of the electrolytic device, is referred to hereinafter as the "anolyte solution" or the "anolyte" and the cation-containing solution, produced in the cathodic chamber of the electrolytic device, is referred to hereinafter as the "catholyte solution" or the "catholyte". The electrolytic device may include an electrolytic cell with predetermined design, geometrical and fluid flow relationships, ensuring optimum fluid flow and recirculation patterns. The cell may have a relatively small, annular, cross-sectional total open area for fluid flow, preferably of about 90 mm 2 , thus causing turbulent fluid flow there through, so as to ensure maximum exposure of the solutions to the electric field. The cell may be a through flow, electrolytic cell with two co-axial cylindrical electrodes, with a tubular ceramic diaphragm located co-axially between the two electrodes, so as to separate an annular inter-electrode space into a co¬ axial, annular cathoiytic and an annular anolytic chamber arrangement. The electrolytic cell is preferably suitable to operate under predetermined operational parameters, including a relatively low current of about 1 to 15 A and preferably of about 5 to 7 A, and a relatively high voltage of about 1 to 48 V, preferably of about 6 to 18 V, and more preferably of 12 V, thus providing a relatively high voltage gradient or electric field strength at the interface between the electrode surface and electrolyte, estimated to be about 10 6 V/cm. The microcidal solution for use in the dental unit may be produced from an aqueous NaCI or NaHCO 3 or Na 2 CO 3 solution, the concentration of which may vary between 0,01 % to 1 % and more specifically between 0.05 % and 0.5% and preferably between 0.1 % and 0.4%, electrolysed to produce cationic and anionic radicals. The anolyte solution may have a redox potential of about + 200 to + 1 100 mV and more specifically about + 600 to + 850 mV and preferably equal or more than + 713mV and a TDS of about 2-4 g/l. The anolyte solution may have a pH of about 6.75 to 8.5, preferably about 7.0 to 7.6, and a conductivity of about 0.1 to 10 mS/cm and more specifically of about 0.1 5 to 4.08 mS/cm, being produced at a current of about 5 Amperes, a voltage of about 12V and a flow rate of about 200 to 500 ml/min and more specifically about 300 to 350 ml/min. The anolyte solution may include species such as CIO; CIO-; HCIO; OH-; HO 2 " ; H 2 O 2 ; O 3 ; S 2 O 8 2" ; and Cl 2 O 6 2' . The above radicals in the anolyte solution have been found to have a suitable synergistic anti-microbial effect against viral organisms, spore and cyst-forming bacteria, fungi and yeast, which compares favourably with sodium hypochlorite and have been found to be particularly effective against Prevotella intermedia, Porphyromonas gingivalis, Streptococcus mutans and Enterococcus faecalis. The catholyte solution may have a pH of about 9.0 - 12.0 and a redox potential of about -864 mV and a conductivity of about 5.92 to 6.03 mS/cm. The catholyte solution may include species such as NaOH; KOH; Ca(OH) 2 ; Mg(OH) 2 ; HO ; H 3 0 2 ; HO 2 " ; H 2 O 2 " ; O 2 " ; OH ' ; and O 2 2' . It is believed that in addition to the normal mechanisms of action involved in elimination of micro-organisms, the oxidising free radicals and other constituents, such as micro-bubbles, present in the anolyte solution act synergistically at a bacterial cellular level, also aiding in the elimination of the micro-organisms in an electrostatic manner. The efficacy of the mixed anolyte and catholyte solution as an irrigating medium for use in specific procedures, such as in the treatment of cavities and/or root canals, may depend upon the concentration of the mixed anolyte and catholyte solution in the receiving water, as measured by the pH, oxidation-reduction potential (ORP), conductivity and TDS of the mixed anolyte and catholyte solution, the exposure time, such as the contact time between the cavity and/or root canal, and the mixed anolyte and catholyte solution and the temperature during application. DETAILED DESCRIPTION OF THE INVENTION Preferred embodiments of the invention will now be described by means of four non-limiting examples. EXAMPLE 1 : Twenty patients requiring the surgical removal of teeth volunteered for this study. They were randomly assigned to one of two groups, Group A and Group B, each including ten patients. The same procedures were followed for both groups except for the coolant medium. In both groups local anaesthesia was administered, full thickness flaps designed, incisions made, flaps reflected, bone removed with rotary burs driven by electrical motors, teeth elevated, flaps repositioned and sutured. Group A (Saline) In Group A the burs of rotary instruments were cooled by sterile saline delivered with a sterile chip syringe. Group B (Electrolytically Activated Solution "STEDS") In Group B the burs were cooled with electrolytically activated water ("STEDS") delivered as an integrated spray through the normal integrated dental unit water lines, confirmed to be free of biofilm contamination. STEDS was produced from a specially manufactured electrolytical reactor, comprising a through flow, electrolytical cell having two co-axial cylindrical electrodes with a co-axial diaphragm between them so as to separate an annular inter-electrode space into cathodic and anodic chambers. The STEDS produced included two separate solutions, namely catholyte and anolyte solutions. The anolyte solution had a pH of about 7.4 and a redox potential of about +1170 mV. The catholyte solution had a pH of about 9,5 and a redox potential of about -980mV. RESULTS All patients were recalled and re-examined at 24 hours, 48 hours, 72 hours and one week post operatively. All complaints, signs and symptoms were categorised and classified according to a specially developed scale. Group A In Group A all patients experienced severe pain, swelling and discomfort at 24 hours, 48 hours, as well as at 72 hours. At one week, 4 of the patients were still experiencing severe symptoms with the other 6 patients experiencing none. Group B In Group B 4 patients experienced mild pain and discomfort at 24 hours. The other 6 experienced no pain. At 48 hours only one patient experienced mild discomfort. At 72 hours all patients were classified fully recovered. It was concluded that electrolytically activated water is superior to sterile saline as coolant and irrigant medium for the surgical removal of teeth. EXAMPLE 2 : Twenty patients who reported for treatment of alveolar osteϊtis volunteered for this study. Informed consent was obtained and the patients randomly assigned to one of two groups, Group A and B. Group A (Saline) In Group A, treatment consisted of the surgical curettage and lavage with sterile saline, under local anaesthesia. Group B (Electrolytically Activated Solution "STEDS") In Group B, treatment consisted of surgical curettage and lavage, using electrolytically activated solution ("STEDS"), also under local anaesthesia. The anolyte and catholyte solutions were used alternately. STEDS was produced from a specially manufactured electrolytical reactor, comprising a through flow, electrolytical cell having two co-axial cylindrical electrodes with a co-axial diaphragm between them so as to separate an annular inter-electrode space into cathodic and anodic chambers. The STEDS produced included two separate solutions, namely catholyte and anolyte solutions. The anolyte solution had a pH of about 7.4 and a redox potential of about +1170 mV. The catholyte solution had a pH of about 9,5 and a redox potential of about -980mV. RESULTS All patients were re-examined at 24 hours, 48 hours, 72 hours and one week post-operatively and signs, symptoms and experience of pain and discomfort noted according to a special scale. Group A In Group A, all patients were still experiencing severe pain at 24 as well as 48 hours. At 72 hours, five of the ten patients in Group A was still experiencing severe pain and discomfort. At one week post operatively three patients were still experiencing moderate to severe pain. Group B In Group B, at 24 hours seven patients were totally free of pain and discomfort and were diagnosed as completely healed from alveolar osteϊtis. The remaining three patients were still experiencing mild to moderate pain but at 48 hours they were also free from pain and were classified as healthy. It was concluded that treatment with electrolytically activated water is an effective, novel, safe and inexpensive method for the treatment of alveolar osteitis. EXAMPLE 3 Sixteen patients requiring periodontal surgery comprising of flap dissection, crown lengthening and or alveolar bone re-contouring procedures volunteered for this study. They were randomly assigned to one of two groups, Group A and Group B. One operator performed all sixteen operations. In Group A the rotary instruments were cooled with sterile saline and in Group B with eiectro-emically activated aqueous solutions. The patients were clinically re-assessed at 24 hours, 1 week later and six weeks post-operatively and at these times the patients were also asked to complete a specially developed questionnaire using a visual analog scale, to quantify their individual subjective experiences of pain. The results were statistically computed and analyzed using students t-test. In Group A all patients suffered severe post-operative pain at 24 hours and 6 of the 8 patients also suffered the same condition at one week post-operatively. Two patients were still suffering moderate pain at 6 weeks post-operatively. In Group B all patients were suffering only mild post-operative pain at 24 hours post-operatively. At one week post-operatively all patients were found to be totally pain free. It was concluded that electrolytically activated water when used as irrigant in periodontal surgical procedures involving alveolar bone resulted in significantly lower levels of post-operatively pain and swelling than when sterile saline was used. EXAMPLE 4 : Nine healthy patients needing implant supported prostheses volunteered for this study and were randomly divided into three Groups namely, Groups A, B and C, comprising three patients each. Informed consent was obtained from the patient and treatment carried out. Group A (Saline) In Group A first stage surgery was carried out in the conventional way using sterile saline delivered via an external line fitted to an electric motor driven instrument. Group B (Electrolytically Activated Solution "STEDS") In Group B first stage surgery was carried out using electrolytically activated water ("STEDS") delivered via an external line fitted to the electric motor driven instrument. Group C In Group C first stage surgery was carried out using electrolytically activated water ("STEDS") delivered directly into and through the electric motor which formed an integral part of a dental unit used in the surgery. This unit was confirmed to be free of biofilm contamination. In Group C, the electrolytically activated water had, in other words, been delivered via the normal dental water lines. Both in Group B and Group C, the STEDS was produced from a specially manufactured electrolytical reactor, comprising a through flow, electrolytical cell having two co-axial cylindrical electrodes with a co-axial diaphragm between them so as to separate an annular inter-electrode space into cathodic and anodic chambers. The STEDS produced included two separate solutions, namely catholyte and anolyte solutions. The anolyte solution had a pH of about 7.4 and a redox potential of about +1170 mV. The catholyte solution had a pH of about 9,5 and a redox potential of about -980mV. In both Groups B and C these two solutions were used alternately. RESULTS First stage surgery was completed as usual and the patients followed up at 24 hours, 1 week, 1 month, 3 months and 6 months. Group A At 24 hours all three patients in Group A experienced severe pain. Groups B and C Patients in Groups B and C experienced no pain. At six months post- operatively second stage surgery was performed and prostheses made and fitted. Three months after that, all implants were found to be stable and functioning and the same was found one year after treatment had been completed. It was concluded that the use of electrolytically activated water was at least as good, possibly better than conventional coolant and irrigants. What was significant was that the use of electrolytically activated water in an integrated dental unit water line was equally effective as when used in an external separate special sterile water line and that it was equally effective as sterile saline delivered in such an external separate water line. This represents a significant saving in equipment and costs.

Claims: CLAIMS 1. An irrigant for use in dental surgical procedures, the irrigant comprising an electrolytically activated aqueous solution, the solution being characterised in having a pH of between 6.75 and 10 with microcidal as well as anti-oxidising, dispersing and surfactant properties, rendering the irrigant bio-compatible and non-corrosive. 2. An irrigant as claimed in claim 1 , characterised in being selected from the group consisting of a mixture of an anion-containing solution and a cation-containing solution; an anion-containing solution, having been generated from a cation-containing solution or a mixture of an anion- containing solution and a cation-containing solution; and a cation- containing solution, having been generated from an anion-containing solution, a cation-containing solution or a mixture of an anion- containing solution and a cation-containing solution. 3. An irrigant as claimed in claim 2, characterised in consisting of a mixture of electrolytically activated, anion-containing solution and electrolytically activated, cation-containing solution in the proportions and the state as generated by a electrolytic device, capable of producing separate electrolytically activated, anion-containing and electrolytically activated, cation-containing solutions, the irrigant consisting of a mixture in a ratio of about 4 to 5 volumes of the electrolytically activated, anion-containing solution to about 1 volume of the electrolytically activated, cation-containing solution, when prepared from an aqueous solution of a chloride or halide salt. 4. An irrigant as claimed in claim 2, characterised in consisting of a mixture of electrolytically activated, anion-containing solution and electrolytically activated, cation-containing solution in the proportions and the state as generated by a electrolytic device, capable of producing separate electrolytically activated, anion-containing and electrolytically activated, cation-containing solutions, the irrigant consisting of a mixture in a ratio of about 2 to 3 volumes of the electrolytically activated, anion-containing solution to about 1 volume of the electrolytically activated, cation-containing solution, when prepared from an aqueous solution of a bicarbonate or carbonate salt . 5. An irrigant as claimed in claim 3 or 4, characterised in having been produced by means of electrolysis of a dilute saline solution of about 0,01 % to 1 %, thus minimising the formation of trihalomethanes and therefore the carcinogenic potential of the solution. 6. An irrigant as claimed in claim 3 or 4, characterised in the anion-containing solution having a redox potential of about + 200 to + 1 200 mV, a TDS of about 2-4 g/l a pH of about 6.75 to 10 and a conductivity of about 0.1 to 10 mS/cm mS/cm, produced at a current of about 2 to 1 5 Amperes, a voltage of about 2 to 48V and a flow rate of about 200 to 500 ml/min. 7. An irrigant as claimed in claim 6, characterised in the anion-containing solution having any one or more of species selected from the group consisting of C ; HCIO; HCI; Hθ2*; HO*; CIO"; H2O2; 1 O2; Ci*; HC.Q2; CIO2; Q*; CIO; CIO ' ; HCIO; OH ' ; H 2 0 2 ; S 2 0 8 2' ; CI0 3 ' ; Cl 2 0 6 2' ; HO 2 ' and 0 3 . 8. . An irrigant as claimed in claim 3 or 4, characterised in the cation-containing solution having a pH of about 9.0 - 12.0, a redox potential of about -864 mV and a conductivity of about 5.92 to 6.03 mS/cm. 9. An irrigant as claimed in claim 8, characterised in the cation containing solution having any one or more of the species selected from the group consisting of NaOH; KOH; Ca(OH) 2 ; Mg(OH) 2 ; HO ' ; H 3 0 2 ; H0 2 " ; H 2 0 2 ": 0 2 ' ; OH " ; O 2 2' . NaOH; HO2*; OH*; H2O2; H* and OH*. 10. The use of an irrigant in dental surgical procedures, the irrigant being characterised in that it is electrolytically activated. 1 1 . A method for irrigating dental surgical procedures, the method including the step of irrigating the wound and the dental surgical instruments with an irrigant as claimed in claim 1 . 12. The method as claimed in claim 1 1 , the method comprising the surgical removal of teeth, the method including the step of irrigating such teeth and at least some of the associated alveoli and rotary instruments with such irrigant. 13. The method as claimed in claim 1 1 , the method comprising the treating of post-extraction alveolar osteϊtis, the method including the step of applying such irrigant to an affected alveoli. 14. The method as claimed in claim 1 1 , the method comprising a periodontal surgical procedure involving alveolar bone, the method including the step of irrigating at least some of the rotary instruments and the alveolar bone with the irrigant. 15. The method as claimed in claim 1 1 , the method comprising first stage implant treatment surgery, the method including the step of irrigating at least some of the dental surgical instruments, the alveolar bone, the basal bone and the implant components with such irrigant. 16. A coolant for dental surgical rotary instruments when used in dental surgical procedures, including procedures such as the surgical removal of teeth, the treatment of alveolar osteitis, periodontal surgical procedures involving alveolar bone and first stage implant treatment surgery, the coolant comprising an irrigant as claimed in claim 1.

Inventors: MARAIS JACOBUS THEODORUS, MARAIS, JACOBUS, THEODORUS
Applicants: MARAIS JACOBUS THEODORUS, RADICAL WATERS IP PTY LTD, MARAIS, JACOBUS, THEODORUS, RADICAL WATERS IP (PTY) LTD
Application year: 2001
Main classification: A61K6
IPC codes: A61C1, A61K6, A61L2