- Email: [email protected]
Soft drink acidity and enamel dissolution
epinephrine. This can be delivered as 2.2 cartridges of 1:100,000 epinephrine or 4.4 cartridges of 1:200,000 epinephrine. Drug and Practitioner Factors.—Local anesthetics each have a maximum recommended dose. Patients who receive a combination of two local anesthetics may experience toxicity because the effects of each drug are additive. The recommendations for such situations reflect how conservatively the practitioner wishes to make the maximum recommended dose calculation. Solo practitioners in an office in a remote location may choose a more conservative dose than practitioners based in hospitals in an operating room or those who work with dental anesthesiologists, monitors, equipment, and advanced emergency medications. Dosages.—To calculate the dose limit for an individual patient, body weight in pounds is converted to kilograms by dividing pounds by 2.2 lb/kg (Table 1). Little research addresses how long after giving the maximum recommended dose a dentist can administer more. The scientific data are
insufficient on this point. A conservative approach limits the dosage to the maximum recommended dose given once a day.
Clinical Significance.—Calculating maximum dose, in addition to the math, must include consideration of whether the patient is obese or emaciated, injection site, cardiovascular status, and medications being taken. Dentists typically practice in a solitary setting. Erring on the conservative side is a wise practice.
Weaver JM: Calculating the maximum recommended dose of local anesthetic. Calif Dent Assoc J 35:61-63, 2007 Reprints available from JM Weaver, The Ohio State Univ, College of Dentistry, Section of Oral and Maxillofacial Surgery, Pathology and Anesthesiology, 305 W 12th Avenue, Columbus, OH 43218
Preventive Dentistry Soft drink acidity and enamel dissolution Background.—Most people consider soft drinks to be harmless even though it has been shown that their principal nutritive element is sugar. Consuming diet drinks assuages fears of too much sugar intake, but both sugared and nonsugared drinks have pH values less than 3.5 and contain phosphoric acid and/or citric acid, both of which contribute to dental erosion. Exposing enamel to soft drinks even for short time periods diminishes enamel microhardness. The relationship between the pH of 20 popular soft drinks and the effect on enamel loss was investigated. Methods.—The 20 drinks included nine cola beverages, eight noncola beverages, two iced teas, and one root beer (Table). Both sugared and unsugared varieties of the drinks were tested. The pH of each drink was measured immediately after opening the can, and the pH of tap water was measured immediately after collection. Two hundred fifty-
300
Dental Abstracts
two slices from the buccal and lingual surfaces of freshly extracted teeth were stored in distilled water until they were divided into 21 groups of 12 each and immersed in the various beverages or tap water. The slices were weighed before immersion, then removed from immersion after 6 hours, dried, and weighed again. This process was repeated after 24 hours and after 48 hours. Results.—The pH values of the noncola drinks were significantly higher than those of the cola drinks. The sugared cola and noncola drinks had lower pH values than the nonsugared versions. The lowest pH was found for RC Cola (2.39) and the highest was found for Mug Root Beer (4.04), with tap water having a pH of 7.67. The mean percent of weight loss in the enamel slices increased with longer immersion times, so the greatest loss of weight occurred after 48 hours of immersion. The highest mean percent of weight loss was with Surge (7.85%) and the
Table.—Beverages Included in the Study, pH Values Upon Opening, and Mean Percent Weight Loss After 48 Hours of Immersion Beverage
Cola Coke Diet Coke Pepsi Diet Pepsi Dr. Pepper Diet Dr. Pepper Cherry Coke RC Cola Mr. Pibb Non-cola Mountain Dew Diet Mountain Dew Squirt Surge Slice Orange Sprite 7 Up Diet 7 Up Iced tea Lemon Brisk Lemon Nestea Root beer Mug root beer Control Tap water
pH
Mean percent weight loss at 48 hours
2.525 3.289 2.530 3.031 2.899 3.169 2.522 2.387 2.902
5.925 1.607 5.619 2.917 2.894 2.220 3.886 5.452 2.352
3.229 3.365 2.898 3.004 3.059 3.298 3.202 3.706
4.199 3.037 5.692 7.85 4.95 4.098 6.17 5.04
2.868 2.969
2.839 3.426
4.038
1.579
7.67
2.45
(Reprinted with permission from General Dentistry, March/April 2007. ª Academy of General Dentistry. All rights reserved. On the Web at www.agd.org. License # GD-1395-JJM.)
lowest was with Mug Root Beer (1.58%). The mean percent weight loss of all the drinks was 4.09%. The difference in
mean percent weight loss between the various drinks was not statistically significant. As a group, noncola drinks had a significantly higher mean percent weight loss than the cola, iced tea, or root beer groups. The diet versions of the drinks showed a consistently lower mean percent weight loss than the sugared versions. Percent weight loss increased as the pH values decreased, demonstrating a weak linear relationship. The noncola drinks had both a significantly higher pH and a significantly higher mean percent weight loss than the cola drinks. Discussion.—The various categories of soft drinks showed a significant difference in pH, with sugared soft drinks having lower pH values than diet versions. As the time of immersion in the drinks increased, the enamel slices showed greater evidence of dissolution. The noncola drinks produced a significantly greater mean percent weight loss than was seen with the cola drinks. pH and percent weight loss demonstrated only a weak negative relationship. pH value did not affect the mean percent weight loss significantly.
Clinical Significance.—Few patients are aware of how acidic the popular and heavily consumed beverages reported here actually are. Awareness of the values reported will better equip clinicians to counsel patients on reducing caries.
Jain P, Nihill P, Sobkowski J, et al: Commercial soft drinks: pH and in vitro dissolution of enamel. Gen Dent March–April:150-154, 2007 Reprints available from Jo Posselt, Academy of General Dentistry; e-mail: [email protected]
Toothbrush wear and plaque removal Background.—Both manual and powered toothbrushes have shown themselves effective in disrupting the plaque biofilm on tooth surfaces. This action is an important contributor to reducing the incidence of dental caries and chronic periodontal disease. Once bristles become worn, however, in vitro and in vivo studies have shown that the toothbrushes’ ability to remove plaque is diminished. Thus it has been recommended that brushes with splayed bristles be replaced, generally every 2 to 3 months. The actual difference in plaque removal efficiency between a new and a 3-month-old brush was evaluated, and the
relationship between brush head wear and plaque removal using a powered rotation-oscillation toothbrush was quantified. Methods.—Thirty-four adults attending a dental clinic took part in this crossover study. Each subject was randomly assigned to use a new brush or a 3-month-old brush before the first visit, then the order was reversed for the second visit. The subjects were scored for presence of plaque after 48 hours of not performing any oral hygiene. Then they used either a new powered rotation–oscillation brush or
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2007
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insufficient on this point. A conservative approach limits the dosage to the maximum recommended dose given once a day.
Clinical Significance.—Calculating maximum dose, in addition to the math, must include consideration of whether the patient is obese or emaciated, injection site, cardiovascular status, and medications being taken. Dentists typically practice in a solitary setting. Erring on the conservative side is a wise practice.
Weaver JM: Calculating the maximum recommended dose of local anesthetic. Calif Dent Assoc J 35:61-63, 2007 Reprints available from JM Weaver, The Ohio State Univ, College of Dentistry, Section of Oral and Maxillofacial Surgery, Pathology and Anesthesiology, 305 W 12th Avenue, Columbus, OH 43218
Preventive Dentistry Soft drink acidity and enamel dissolution Background.—Most people consider soft drinks to be harmless even though it has been shown that their principal nutritive element is sugar. Consuming diet drinks assuages fears of too much sugar intake, but both sugared and nonsugared drinks have pH values less than 3.5 and contain phosphoric acid and/or citric acid, both of which contribute to dental erosion. Exposing enamel to soft drinks even for short time periods diminishes enamel microhardness. The relationship between the pH of 20 popular soft drinks and the effect on enamel loss was investigated. Methods.—The 20 drinks included nine cola beverages, eight noncola beverages, two iced teas, and one root beer (Table). Both sugared and unsugared varieties of the drinks were tested. The pH of each drink was measured immediately after opening the can, and the pH of tap water was measured immediately after collection. Two hundred fifty-
300
Dental Abstracts
two slices from the buccal and lingual surfaces of freshly extracted teeth were stored in distilled water until they were divided into 21 groups of 12 each and immersed in the various beverages or tap water. The slices were weighed before immersion, then removed from immersion after 6 hours, dried, and weighed again. This process was repeated after 24 hours and after 48 hours. Results.—The pH values of the noncola drinks were significantly higher than those of the cola drinks. The sugared cola and noncola drinks had lower pH values than the nonsugared versions. The lowest pH was found for RC Cola (2.39) and the highest was found for Mug Root Beer (4.04), with tap water having a pH of 7.67. The mean percent of weight loss in the enamel slices increased with longer immersion times, so the greatest loss of weight occurred after 48 hours of immersion. The highest mean percent of weight loss was with Surge (7.85%) and the
Table.—Beverages Included in the Study, pH Values Upon Opening, and Mean Percent Weight Loss After 48 Hours of Immersion Beverage
Cola Coke Diet Coke Pepsi Diet Pepsi Dr. Pepper Diet Dr. Pepper Cherry Coke RC Cola Mr. Pibb Non-cola Mountain Dew Diet Mountain Dew Squirt Surge Slice Orange Sprite 7 Up Diet 7 Up Iced tea Lemon Brisk Lemon Nestea Root beer Mug root beer Control Tap water
pH
Mean percent weight loss at 48 hours
2.525 3.289 2.530 3.031 2.899 3.169 2.522 2.387 2.902
5.925 1.607 5.619 2.917 2.894 2.220 3.886 5.452 2.352
3.229 3.365 2.898 3.004 3.059 3.298 3.202 3.706
4.199 3.037 5.692 7.85 4.95 4.098 6.17 5.04
2.868 2.969
2.839 3.426
4.038
1.579
7.67
2.45
(Reprinted with permission from General Dentistry, March/April 2007. ª Academy of General Dentistry. All rights reserved. On the Web at www.agd.org. License # GD-1395-JJM.)
lowest was with Mug Root Beer (1.58%). The mean percent weight loss of all the drinks was 4.09%. The difference in
mean percent weight loss between the various drinks was not statistically significant. As a group, noncola drinks had a significantly higher mean percent weight loss than the cola, iced tea, or root beer groups. The diet versions of the drinks showed a consistently lower mean percent weight loss than the sugared versions. Percent weight loss increased as the pH values decreased, demonstrating a weak linear relationship. The noncola drinks had both a significantly higher pH and a significantly higher mean percent weight loss than the cola drinks. Discussion.—The various categories of soft drinks showed a significant difference in pH, with sugared soft drinks having lower pH values than diet versions. As the time of immersion in the drinks increased, the enamel slices showed greater evidence of dissolution. The noncola drinks produced a significantly greater mean percent weight loss than was seen with the cola drinks. pH and percent weight loss demonstrated only a weak negative relationship. pH value did not affect the mean percent weight loss significantly.
Clinical Significance.—Few patients are aware of how acidic the popular and heavily consumed beverages reported here actually are. Awareness of the values reported will better equip clinicians to counsel patients on reducing caries.
Jain P, Nihill P, Sobkowski J, et al: Commercial soft drinks: pH and in vitro dissolution of enamel. Gen Dent March–April:150-154, 2007 Reprints available from Jo Posselt, Academy of General Dentistry; e-mail: [email protected]
Toothbrush wear and plaque removal Background.—Both manual and powered toothbrushes have shown themselves effective in disrupting the plaque biofilm on tooth surfaces. This action is an important contributor to reducing the incidence of dental caries and chronic periodontal disease. Once bristles become worn, however, in vitro and in vivo studies have shown that the toothbrushes’ ability to remove plaque is diminished. Thus it has been recommended that brushes with splayed bristles be replaced, generally every 2 to 3 months. The actual difference in plaque removal efficiency between a new and a 3-month-old brush was evaluated, and the
relationship between brush head wear and plaque removal using a powered rotation-oscillation toothbrush was quantified. Methods.—Thirty-four adults attending a dental clinic took part in this crossover study. Each subject was randomly assigned to use a new brush or a 3-month-old brush before the first visit, then the order was reversed for the second visit. The subjects were scored for presence of plaque after 48 hours of not performing any oral hygiene. Then they used either a new powered rotation–oscillation brush or
Volume 52
Issue 5
2007
301