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Quantitative bactericidal effectiveness of an old and a new endodontic irrigant
JOURNAL OF ENDODONTICS ] VOL 1, NO 5, MAY 1975
Quantitative
bactericidal
effectiveness
of a n old a n d
a
ilow
endodontic irrigant H o w a r d Martin. DMD. Silver Sprinq, M d
The quantitative bactericidal e f f i c i e n c y of p o t e n t i a t e d a c i d 1,5 pentanedial and sodium hypochlorite as endodontic irriqatinq s o l u t i o n s w a s c o m p a r e d with t h e u s e of four test m i c r o o r g a n i s m s . P o t e n t i a t e d a c i d 1,5 p e n t a n e d i a l had a superior reductive action on t h e b a c t e r i a l p o p u l a t i o n s . It h a s potential as an endoclontic i r r i q a t i n q a q e n t b e c a u s e of its properties as a bactericide.
tentiated acid 1,5 pentanedial, have proved to be rapid acting, simple-touse, aqueous chemical systems for sterilization or disinfection. No studies regarding the quantification of the bactericidal efficiency of sodium hypochlorite or potentiated acid 1,5 pentanedial have been reported previously. The current study was designed to investigate the bactericidal efficacy of both agents as used in endodontic irrigation. METHODS A N D MATERIALS
The purpose of irrigation in endodontics is to "eliminate the bulk of bacteria in the canal. 'u Irrigation is an indispensable aid in achieving thorough debridement and in preparing and disinfecting the canal,'-' Ingle and Zeldow a showed that the irrigating solution should have antibacterial properties to he effective. Auerbach~ and Stewart ~ have shown that canals can be rendered free of bacterial growth in a high percentage of cases with irrigation. The favored irrigation agent currently is sodium hypochlorite (NoOCI), a slightly caustic, chlorinereleasing chemical. However, breakthroughs in understanding biocidal mechanisms 6 have been achieved recently. The aldehydes, especially po164
Sodium hypochlorite 5.5%* was compared to potentiated acid 1,5 pentanedial 2 % . t The test organisms were Streptococcus ]aecalis (ATCC 4279), Str mitis ( A T C C 6249), Staphylococcus aureus ( A T C C 25923 ), and Escherichia coli ( A T C C 25922)At The study was divided into two parts. The first part (experiments 13) tested the agents' quantitative bactericidal effects as they would be used in normally occurring endodontic irrigation procedures. The second part (experiment 4) determined the serial dilution effectiveness of potentiated acid 1,5 pentanedial against the test organisms. Experiment 1 Sixteen
extracted
human
molars
(eight maxillary and eight mandibular) were prepared by an incremental telescopic filing technique. 7 After mechanical preparation, the teeth were ultrasonically cleaned for five minutes. The apices were then sealed with Cavil to prevent leakage. Coldcuring acrylic molds were placed around all roots to the cementoenameI junction. The prepared teeth were then autoclaved for 30 minutes and allowed to cool to room temperature. An actively growing culture of each of the test organisms, with a predetermined number of organisms per milliliter, was then used for inoculation. A sterile B-D plastipak tuberculin syringe with a 28-gauge needle was used for insertion of the culture into the pulpal chamber. A n aliquot of 0.2 ml of the indicated medicament was placed in the same chamber. The molar was then refiled. At the end of the indicated time, a 0.001 loop of the material was removed from each canal and placed in fluid thioglycollate medium. The fluid thioglycollate medium was incubated at room temperature for one hour to provide for growth enhancement. An aliquot of the fluid thioglycollate was placed in sterile Petri dishes, mixed with plate count agar, and incubated at 35 C for 24 hours.
JOURNAL OF ENDODONTICS r VOL 1, NO 5, MAY 1975
Bacterial counts were then made with the aid of a Quebec colony counter. All counts were calculated to a per milliliter basis. 2 All procedures were identical to experiment 1 except that equal portions of culture and horse serum protein were prepared. An aliquot of this inoculum was placed in each of the sterile prepared molars. Experiment
Experiment 3 In this experiment, the culture was placed in the sterile prepared molars. The culture was then exposed to an equal amount of potentiated acid 1,5 pentanedial, without mechanical instrumentation. At the end of the indicated exposure time, a 0.001 loop of the material was removed from the molar and placed in tryptic soy broth. The broth was incubated at room temperature for one hour to enhance growth. An aliquot of the tryptic soy broth was then plated and mixed with plate count agar. The plates were incubated at 35 C for 24 hours. Counts were made with the aid of a Quebec colony counter. The controls were based on the inoculation of culture taken at the beginning and end of all" sessions with each organism. A buffer solution was used and bacterial counts were taken at the beginning and end of the experiments to determine quantification
maintenance. These ate included in experiment 3. Experiment 4 Only potentiated acid 1,5 pentanedial was used in this experiment. Ten milliliters of various concentrations of the medicament were inoculated separately by a 0.001 loop of actively growing culture of test bacteria and were mixed. At the end of the exposure time, 1 ml was transferred to 5 ml of tryptic soy broth. After one hour of incubation for enrichment, the entire contents of the tryptic soy broth were plated with the use of plate count agar. Incubation was at 35 C for 24 hours. All resulting percentage compositions refer to the material in addition to glass distilled water, that is, 90% is equal to 9 ml pentanedial and 1 ml glass distilled water. RESULTS Experiment
1
Table 1 shows the number of viable bacteria remaining at the specified time intervals, during mechanical filing of a 50% culture and 50% medicament inoculum, in the sterile prepared molars. Both solutions had efficient bactericidal actions under the test conditions. Experiment 2 Table 2 shows
the
number
of
viable bacteria remaining at the specified time intervals, during instrumentation with a 50% culture and horse serum and 50% medicament, in the sterile prepared molars. Overall, in the presence of horse serum protein, potentiated acid 1,5 pentanedial exerted a higher degree of immediate bactericidal action than did NaOC1.
Experiment 3 Table 3 shows the effectiveness of potentiated acid 1,5 pentanedial on the test organisms without manipulation. Abnormally large inoculums were used as a test under extreme conditions. All bacterial counts were definitely reduced within a six-minute period. Experiment 4 Table 4 shows the effectiveness of potentiated acid 1,5 pentanedial, in various concentrations, against the test organisms. It indicates that a 50% dilution would be as effective as a 100% concentration. DISCUSSION
The importance of debridement, medication, shaping, and obturation of the root canal to the success of endodontic procedures is unquestionable. However, an often underemphasized phase is irrigation. The objectives of irrigation are to aid in debridement, to serve as a lavage, and to reduce the bacterial count. Ingle and Zeldow a
Table I 9 Bactmqcidal effect with 50% culture and 50% medicammst and instrumentation. Time (in rain)
0.0 O.J
1.0 2.0 4.0
Str faecalis NaOC1
2,800,000 5,400 360 0 0
Pentanedial
3,200,000 730 360 0 0
Str mitis NaOCI
54,000 2,700 220 220 0
Pentanedial
50,000 37,000 29,000 1,000 220
E coli
Sta aureus NaOCI
Pentanedial
NaOCI
800,000 55,000 5,500 4,000 1,400
890,000 2,000 1,000 360 360
7,000 330 330 440 0
Pentanedial
24,000 330 220 220 0
All counts calculated to a per milliliter level.
165
IOURNAL
attributed the high percentage of negative cultures of Auerbach ~ and Stewart 5 to the antibacterial aspects of their irrigating solutions. Shapiro and others 8 used benzalkonium chloride as an irrigant; it yielded 75% negative cultures. However, it was used in conjunction with camphorated parachlorophenol which added to the effectiveness of the irrigating solution. Ingle and Zeldow a reported only 4.6% negative cultures with sterile water irrigation as compared to 78% for Auerbach 4 and 76% for Stewart. ~ This clearly shows the importance of the bactericidal component of irrigating solutions, and its importance in endodontic irrigation. A new microbiocide, potentiated acid 1,5 pentanediaI, was compared to sodium hypochlorite 5.5% as an endodon,tic irrigating solution. Potentiated acid 1,5 pentanedial is a stable compound that has a two-year shelf life9 as compared to a three-month shelf life for NaOC1. Alkaline pentanedial solutions, such as Cidex, previously used as disinfecting agents, have only a two-week shelf life after
'166
being activated with a buffer. The biocidal activity of potentiated acid 1,5 penlanedial is due to its aklylating properties. 10 The activator, a mixture of nonionic ethoxylates of isomeric linear alcohols, increases the wetability of bacterial walls and allows for faster penetration of the medicament. Its surface tension also is low for easier penetration. 11 The biocidal activity of sodium hypochlorite is due to its ability to release about 1% available chlorine to form hypoehlorous acid. 2 The p H of NaOC1 is 11.7 while the pH of potentiated acid 1,5 pentanedial is 5.8. Potentiated acid 1,5 pentanedial is active over a wide pH range; this may be an important benefit when one considers the varied pH conditions that may be encountered in the presence of inflammatory tissue. Since potentiated acid 1,5 pentanedial does coagulate blood, the removal of hemorrhagic tissue should be made less difficult2 2 Experiment 1 simulated conditions where organisms alone would be encountered under irrigation and filing conditions. Experiment 2 simulated
OF ENDODONTICS
I V O L I, N O
5, M A Y
1975
conditions where organisms in addition to serum proteins would be encountered under irrigation and filing conditions. Experiment 3 simulated conditions where no mechanical advantage would be used; contact alone was employed. Experiment 4 tested potentiated acid 1,5 pentanedial when diluted. An extremely heavy plaque of organisms was used as a more stringent test. 13 The ability of bactericidal agents to maintain their activity in the presence of serum proteins is extremely important in root canal therapy. Chlorine-releasing compounds are extensively inactivated by proteinaceous material. Therefore, the full germicidal potential of NaOC1 cannot be rea/ized until thorough debridement has been accomplished. 14 Table 2 illustrates that potentiated acid 1,5 pentanedial was minimally affected by serum proteins. Ayerst laboratories 15 reported that a five-minute exposure regardless of the suspending medium seemed adequate for a complete inhibition of the growth of ten test bacteria (some of which are found in
JOURNAL OF ENDODONTICS I VOL 1, NO 5, MAY 1975
Table 4 9 Serial dilution effect of 2% potentiated acid 1,5 pontan~ltal for a one-mlntate exposure.
Dilution ( % ) concentration 100
Str faecalis .
.
Str mitis .
Sta aureus
E coil
.
90
.
80
-
-
+
-
70
-
-
+
-
60
-
+
+ +
-
50
+
+
+ +
+
40
+
+
+ + +
-
30 20
+++
++
+++
+
+++ ++++ ++++
+++ +++ ++++
+++ ++++ ++++
++ ++ ++++
10 0
.
.
root canals). A buffer and a protein solution were tested. Potentiated acid 1,5 pentanedial should be m o r e bactericidal than N a O C I , u n d e r practical conditions, when serum proteins are present. Shih and associates '14 study on the bactericidal efficiency of N a O C 1 did not m a k e sufficient use of serum proteins for organic material simulation nor was there any quantification of bactericidal ability. Table 3 shows the i m p o r t a n c e of contact for effectiveness. Table 4 shows that as long as contact exists, a 1% solution of potentiated acid 1,5 pentanedial should be sufficient to maintain bacterial efficacy. E n g s t r 6 m Jq; claimed that enterococci were difficult to eradicate in endodontic treatment. Both test medicaments in the current study were able to destroy effectively the representative Str /aecalis. Sta aureus is one of the more difficult organisms .to eliminate from the canal. G o l d m a n and Pearson, lr in postdebridement studies, showed that staphylococci appeared in 17% of the test teeth tested with Sta aureus as the d o m i n a n t coccus. Potentiated acid 1,5 pentanedial was superior to N a O C 1 in the elimination of this resistant bacterial form. Str mitis was chosen since Myers and associates is showed that it was one of the most c o m m o n organisms involved in culture reversals from negative to positive. Potentiated acid
.
1,5 pentanedial was superior to N a O C I in the elimination of this organism. SUMMARY
A n evaluation and a comparison were m a d e of an old endodontic irrigant and a proposed new one. Sodium hypochlorite was c o m p a r e d under varying conditions with potentiated acid 1,5 pentanedial to determine their quanti,tative bactericidal effects on f o u r microorganisms commonly encountered in endodontic procedures. Both agents were bactericidal but potentiated acid 1,5 pentanedial was more germicidal in the presence of serum proteins. A 1% solution of potentiated acid 1,5 pentanedial would be an efficient bactericidal irrigating solution. *Clorox, Clorox Co., Oakland, Calif. "~Sonacide, Wave Energy Systems, Inc. 1600 Madison Ave, New York, NY. r by England Laboratories, Beltsville, Md. The author thanks Dr. J. P. Norris for his assistance in this study. Dr. Martin is a professional lecturer in endodontics, School of Dentistry, Georgetown University, Washington, DC. Requests for reprints should be directed to Dr. Howard Martin, 909 Pershing Dr, Silver Spring, Md 20910. References
1. Luebke, R. Pulp cavity debridement and disinfection. Dent Clin North Am 11:603 Nov 1967.
2. Penick, E., and Osetek, E. Intracanal drugs and chemicals in endodontic therapy. Dent Clin North Am 14:743 Oct 1970. 3. Ingle, J., and Zeldow, B. An evaluation of mechanical instrumentation and the negative culture in endodontic therapy. J A D A 57:471 Oct 1958. 4. Auerbach, M. Antibiotics vs. instrumentation in endodontics. NY State Dent J 19:225 May 1953. 5. Stewart, G. Importance of chemomechanical preparation of the root canal. Oral Surg 8:993 Sept 1955. 6. Boucher, R. M.: Last, A. J.; and Smith, D. K. Biocidal mechanisms of saturated dialdehydes. Proc West Pharmacol Soc 16:282 Feb 1973. 7. Martin, H. A telescopic technique for endodontics. J District Columbia Dent Soc 49:12 Summer 1974. 8. Shapiro, S.: Heling, B.; and Erb, A. Benzalkonium chloride in root canal therapy. J Oral Med 21:123 July 1966. 9. Boucher, R. M. Potentiated acid 1,5 pentanedial solution--a new chemical sterilizing and disinfecting agent. Am J Hosp Pharm 31:546 June 1974. 10. Bruch, C.; Bruch, M.; and Benarde, M. Disinfection. New York, Marcel Dekker Inc., 1970, chapter 6. 11. Stonehill, A.; Krop, S.; and Boric, P. Buffered glutaraldehyde, a new chemical sterilizing solution. Am J Hosp Pharm 20:458, 1963. 12. Last, A. Physical effects of Sonacide on blood and medical surgical instruments. Ontario Research Foundation Report. June 1973. 13. Treanor, H., Jr., and Goldman, M. Bactericidal efficiency of intracanal medications. Oral Surg 33:791 May 1972. 14. Shih, M.; Marshall, F.; Rose, S. Bactericidal efficiency of sodium hypochlorite as an endodontic irrigant. Oral Surg 29:613 April 1970. 15. Baker, H., and Sidorowicz, A. Potentiated acid 1,5 pentanedial evaluation. Intramural report. Montreal, Canada, Ayerst Laboratories, Feb 1974. 16. Engstr6m, B. Significance of enterococci in root canal treatment. Odontol Revy 15:87 No. 2, 1964. 17. Goldman, M., and Pearson, A. Postdebridement bacterial flora and antibiotic sensitivity. Oral Surg 28:897 Dec 1969. 18. Myers, J.; Marshall, F.; and Rosen, S. Incidence and identity of microorganisms present in root canals at filling following culture reversals. Oral Surg 28 :889 Dec 1969. 167
Quantitative
bactericidal
effectiveness
of a n old a n d
a
ilow
endodontic irrigant H o w a r d Martin. DMD. Silver Sprinq, M d
The quantitative bactericidal e f f i c i e n c y of p o t e n t i a t e d a c i d 1,5 pentanedial and sodium hypochlorite as endodontic irriqatinq s o l u t i o n s w a s c o m p a r e d with t h e u s e of four test m i c r o o r g a n i s m s . P o t e n t i a t e d a c i d 1,5 p e n t a n e d i a l had a superior reductive action on t h e b a c t e r i a l p o p u l a t i o n s . It h a s potential as an endoclontic i r r i q a t i n q a q e n t b e c a u s e of its properties as a bactericide.
tentiated acid 1,5 pentanedial, have proved to be rapid acting, simple-touse, aqueous chemical systems for sterilization or disinfection. No studies regarding the quantification of the bactericidal efficiency of sodium hypochlorite or potentiated acid 1,5 pentanedial have been reported previously. The current study was designed to investigate the bactericidal efficacy of both agents as used in endodontic irrigation. METHODS A N D MATERIALS
The purpose of irrigation in endodontics is to "eliminate the bulk of bacteria in the canal. 'u Irrigation is an indispensable aid in achieving thorough debridement and in preparing and disinfecting the canal,'-' Ingle and Zeldow a showed that the irrigating solution should have antibacterial properties to he effective. Auerbach~ and Stewart ~ have shown that canals can be rendered free of bacterial growth in a high percentage of cases with irrigation. The favored irrigation agent currently is sodium hypochlorite (NoOCI), a slightly caustic, chlorinereleasing chemical. However, breakthroughs in understanding biocidal mechanisms 6 have been achieved recently. The aldehydes, especially po164
Sodium hypochlorite 5.5%* was compared to potentiated acid 1,5 pentanedial 2 % . t The test organisms were Streptococcus ]aecalis (ATCC 4279), Str mitis ( A T C C 6249), Staphylococcus aureus ( A T C C 25923 ), and Escherichia coli ( A T C C 25922)At The study was divided into two parts. The first part (experiments 13) tested the agents' quantitative bactericidal effects as they would be used in normally occurring endodontic irrigation procedures. The second part (experiment 4) determined the serial dilution effectiveness of potentiated acid 1,5 pentanedial against the test organisms. Experiment 1 Sixteen
extracted
human
molars
(eight maxillary and eight mandibular) were prepared by an incremental telescopic filing technique. 7 After mechanical preparation, the teeth were ultrasonically cleaned for five minutes. The apices were then sealed with Cavil to prevent leakage. Coldcuring acrylic molds were placed around all roots to the cementoenameI junction. The prepared teeth were then autoclaved for 30 minutes and allowed to cool to room temperature. An actively growing culture of each of the test organisms, with a predetermined number of organisms per milliliter, was then used for inoculation. A sterile B-D plastipak tuberculin syringe with a 28-gauge needle was used for insertion of the culture into the pulpal chamber. A n aliquot of 0.2 ml of the indicated medicament was placed in the same chamber. The molar was then refiled. At the end of the indicated time, a 0.001 loop of the material was removed from each canal and placed in fluid thioglycollate medium. The fluid thioglycollate medium was incubated at room temperature for one hour to provide for growth enhancement. An aliquot of the fluid thioglycollate was placed in sterile Petri dishes, mixed with plate count agar, and incubated at 35 C for 24 hours.
JOURNAL OF ENDODONTICS r VOL 1, NO 5, MAY 1975
Bacterial counts were then made with the aid of a Quebec colony counter. All counts were calculated to a per milliliter basis. 2 All procedures were identical to experiment 1 except that equal portions of culture and horse serum protein were prepared. An aliquot of this inoculum was placed in each of the sterile prepared molars. Experiment
Experiment 3 In this experiment, the culture was placed in the sterile prepared molars. The culture was then exposed to an equal amount of potentiated acid 1,5 pentanedial, without mechanical instrumentation. At the end of the indicated exposure time, a 0.001 loop of the material was removed from the molar and placed in tryptic soy broth. The broth was incubated at room temperature for one hour to enhance growth. An aliquot of the tryptic soy broth was then plated and mixed with plate count agar. The plates were incubated at 35 C for 24 hours. Counts were made with the aid of a Quebec colony counter. The controls were based on the inoculation of culture taken at the beginning and end of all" sessions with each organism. A buffer solution was used and bacterial counts were taken at the beginning and end of the experiments to determine quantification
maintenance. These ate included in experiment 3. Experiment 4 Only potentiated acid 1,5 pentanedial was used in this experiment. Ten milliliters of various concentrations of the medicament were inoculated separately by a 0.001 loop of actively growing culture of test bacteria and were mixed. At the end of the exposure time, 1 ml was transferred to 5 ml of tryptic soy broth. After one hour of incubation for enrichment, the entire contents of the tryptic soy broth were plated with the use of plate count agar. Incubation was at 35 C for 24 hours. All resulting percentage compositions refer to the material in addition to glass distilled water, that is, 90% is equal to 9 ml pentanedial and 1 ml glass distilled water. RESULTS Experiment
1
Table 1 shows the number of viable bacteria remaining at the specified time intervals, during mechanical filing of a 50% culture and 50% medicament inoculum, in the sterile prepared molars. Both solutions had efficient bactericidal actions under the test conditions. Experiment 2 Table 2 shows
the
number
of
viable bacteria remaining at the specified time intervals, during instrumentation with a 50% culture and horse serum and 50% medicament, in the sterile prepared molars. Overall, in the presence of horse serum protein, potentiated acid 1,5 pentanedial exerted a higher degree of immediate bactericidal action than did NaOC1.
Experiment 3 Table 3 shows the effectiveness of potentiated acid 1,5 pentanedial on the test organisms without manipulation. Abnormally large inoculums were used as a test under extreme conditions. All bacterial counts were definitely reduced within a six-minute period. Experiment 4 Table 4 shows the effectiveness of potentiated acid 1,5 pentanedial, in various concentrations, against the test organisms. It indicates that a 50% dilution would be as effective as a 100% concentration. DISCUSSION
The importance of debridement, medication, shaping, and obturation of the root canal to the success of endodontic procedures is unquestionable. However, an often underemphasized phase is irrigation. The objectives of irrigation are to aid in debridement, to serve as a lavage, and to reduce the bacterial count. Ingle and Zeldow a
Table I 9 Bactmqcidal effect with 50% culture and 50% medicammst and instrumentation. Time (in rain)
0.0 O.J
1.0 2.0 4.0
Str faecalis NaOC1
2,800,000 5,400 360 0 0
Pentanedial
3,200,000 730 360 0 0
Str mitis NaOCI
54,000 2,700 220 220 0
Pentanedial
50,000 37,000 29,000 1,000 220
E coli
Sta aureus NaOCI
Pentanedial
NaOCI
800,000 55,000 5,500 4,000 1,400
890,000 2,000 1,000 360 360
7,000 330 330 440 0
Pentanedial
24,000 330 220 220 0
All counts calculated to a per milliliter level.
165
IOURNAL
attributed the high percentage of negative cultures of Auerbach ~ and Stewart 5 to the antibacterial aspects of their irrigating solutions. Shapiro and others 8 used benzalkonium chloride as an irrigant; it yielded 75% negative cultures. However, it was used in conjunction with camphorated parachlorophenol which added to the effectiveness of the irrigating solution. Ingle and Zeldow a reported only 4.6% negative cultures with sterile water irrigation as compared to 78% for Auerbach 4 and 76% for Stewart. ~ This clearly shows the importance of the bactericidal component of irrigating solutions, and its importance in endodontic irrigation. A new microbiocide, potentiated acid 1,5 pentanediaI, was compared to sodium hypochlorite 5.5% as an endodon,tic irrigating solution. Potentiated acid 1,5 pentanedial is a stable compound that has a two-year shelf life9 as compared to a three-month shelf life for NaOC1. Alkaline pentanedial solutions, such as Cidex, previously used as disinfecting agents, have only a two-week shelf life after
'166
being activated with a buffer. The biocidal activity of potentiated acid 1,5 penlanedial is due to its aklylating properties. 10 The activator, a mixture of nonionic ethoxylates of isomeric linear alcohols, increases the wetability of bacterial walls and allows for faster penetration of the medicament. Its surface tension also is low for easier penetration. 11 The biocidal activity of sodium hypochlorite is due to its ability to release about 1% available chlorine to form hypoehlorous acid. 2 The p H of NaOC1 is 11.7 while the pH of potentiated acid 1,5 pentanedial is 5.8. Potentiated acid 1,5 pentanedial is active over a wide pH range; this may be an important benefit when one considers the varied pH conditions that may be encountered in the presence of inflammatory tissue. Since potentiated acid 1,5 pentanedial does coagulate blood, the removal of hemorrhagic tissue should be made less difficult2 2 Experiment 1 simulated conditions where organisms alone would be encountered under irrigation and filing conditions. Experiment 2 simulated
OF ENDODONTICS
I V O L I, N O
5, M A Y
1975
conditions where organisms in addition to serum proteins would be encountered under irrigation and filing conditions. Experiment 3 simulated conditions where no mechanical advantage would be used; contact alone was employed. Experiment 4 tested potentiated acid 1,5 pentanedial when diluted. An extremely heavy plaque of organisms was used as a more stringent test. 13 The ability of bactericidal agents to maintain their activity in the presence of serum proteins is extremely important in root canal therapy. Chlorine-releasing compounds are extensively inactivated by proteinaceous material. Therefore, the full germicidal potential of NaOC1 cannot be rea/ized until thorough debridement has been accomplished. 14 Table 2 illustrates that potentiated acid 1,5 pentanedial was minimally affected by serum proteins. Ayerst laboratories 15 reported that a five-minute exposure regardless of the suspending medium seemed adequate for a complete inhibition of the growth of ten test bacteria (some of which are found in
JOURNAL OF ENDODONTICS I VOL 1, NO 5, MAY 1975
Table 4 9 Serial dilution effect of 2% potentiated acid 1,5 pontan~ltal for a one-mlntate exposure.
Dilution ( % ) concentration 100
Str faecalis .
.
Str mitis .
Sta aureus
E coil
.
90
.
80
-
-
+
-
70
-
-
+
-
60
-
+
+ +
-
50
+
+
+ +
+
40
+
+
+ + +
-
30 20
+++
++
+++
+
+++ ++++ ++++
+++ +++ ++++
+++ ++++ ++++
++ ++ ++++
10 0
.
.
root canals). A buffer and a protein solution were tested. Potentiated acid 1,5 pentanedial should be m o r e bactericidal than N a O C I , u n d e r practical conditions, when serum proteins are present. Shih and associates '14 study on the bactericidal efficiency of N a O C 1 did not m a k e sufficient use of serum proteins for organic material simulation nor was there any quantification of bactericidal ability. Table 3 shows the i m p o r t a n c e of contact for effectiveness. Table 4 shows that as long as contact exists, a 1% solution of potentiated acid 1,5 pentanedial should be sufficient to maintain bacterial efficacy. E n g s t r 6 m Jq; claimed that enterococci were difficult to eradicate in endodontic treatment. Both test medicaments in the current study were able to destroy effectively the representative Str /aecalis. Sta aureus is one of the more difficult organisms .to eliminate from the canal. G o l d m a n and Pearson, lr in postdebridement studies, showed that staphylococci appeared in 17% of the test teeth tested with Sta aureus as the d o m i n a n t coccus. Potentiated acid 1,5 pentanedial was superior to N a O C 1 in the elimination of this resistant bacterial form. Str mitis was chosen since Myers and associates is showed that it was one of the most c o m m o n organisms involved in culture reversals from negative to positive. Potentiated acid
.
1,5 pentanedial was superior to N a O C I in the elimination of this organism. SUMMARY
A n evaluation and a comparison were m a d e of an old endodontic irrigant and a proposed new one. Sodium hypochlorite was c o m p a r e d under varying conditions with potentiated acid 1,5 pentanedial to determine their quanti,tative bactericidal effects on f o u r microorganisms commonly encountered in endodontic procedures. Both agents were bactericidal but potentiated acid 1,5 pentanedial was more germicidal in the presence of serum proteins. A 1% solution of potentiated acid 1,5 pentanedial would be an efficient bactericidal irrigating solution. *Clorox, Clorox Co., Oakland, Calif. "~Sonacide, Wave Energy Systems, Inc. 1600 Madison Ave, New York, NY. r by England Laboratories, Beltsville, Md. The author thanks Dr. J. P. Norris for his assistance in this study. Dr. Martin is a professional lecturer in endodontics, School of Dentistry, Georgetown University, Washington, DC. Requests for reprints should be directed to Dr. Howard Martin, 909 Pershing Dr, Silver Spring, Md 20910. References
1. Luebke, R. Pulp cavity debridement and disinfection. Dent Clin North Am 11:603 Nov 1967.
2. Penick, E., and Osetek, E. Intracanal drugs and chemicals in endodontic therapy. Dent Clin North Am 14:743 Oct 1970. 3. Ingle, J., and Zeldow, B. An evaluation of mechanical instrumentation and the negative culture in endodontic therapy. J A D A 57:471 Oct 1958. 4. Auerbach, M. Antibiotics vs. instrumentation in endodontics. NY State Dent J 19:225 May 1953. 5. Stewart, G. Importance of chemomechanical preparation of the root canal. Oral Surg 8:993 Sept 1955. 6. Boucher, R. M.: Last, A. J.; and Smith, D. K. Biocidal mechanisms of saturated dialdehydes. Proc West Pharmacol Soc 16:282 Feb 1973. 7. Martin, H. A telescopic technique for endodontics. J District Columbia Dent Soc 49:12 Summer 1974. 8. Shapiro, S.: Heling, B.; and Erb, A. Benzalkonium chloride in root canal therapy. J Oral Med 21:123 July 1966. 9. Boucher, R. M. Potentiated acid 1,5 pentanedial solution--a new chemical sterilizing and disinfecting agent. Am J Hosp Pharm 31:546 June 1974. 10. Bruch, C.; Bruch, M.; and Benarde, M. Disinfection. New York, Marcel Dekker Inc., 1970, chapter 6. 11. Stonehill, A.; Krop, S.; and Boric, P. Buffered glutaraldehyde, a new chemical sterilizing solution. Am J Hosp Pharm 20:458, 1963. 12. Last, A. Physical effects of Sonacide on blood and medical surgical instruments. Ontario Research Foundation Report. June 1973. 13. Treanor, H., Jr., and Goldman, M. Bactericidal efficiency of intracanal medications. Oral Surg 33:791 May 1972. 14. Shih, M.; Marshall, F.; Rose, S. Bactericidal efficiency of sodium hypochlorite as an endodontic irrigant. Oral Surg 29:613 April 1970. 15. Baker, H., and Sidorowicz, A. Potentiated acid 1,5 pentanedial evaluation. Intramural report. Montreal, Canada, Ayerst Laboratories, Feb 1974. 16. Engstr6m, B. Significance of enterococci in root canal treatment. Odontol Revy 15:87 No. 2, 1964. 17. Goldman, M., and Pearson, A. Postdebridement bacterial flora and antibiotic sensitivity. Oral Surg 28:897 Dec 1969. 18. Myers, J.; Marshall, F.; and Rosen, S. Incidence and identity of microorganisms present in root canals at filling following culture reversals. Oral Surg 28 :889 Dec 1969. 167