Annotation Abrasion of Enamel and Cementum in Human Teeth Due to Toothbrushing Estimated by SEM ix LUSTMAN, J. ILERSHIKOVSTz, and 1. GF oAA DeJpartmtrnts of Oral Rehabilitation, Oral Surgerv, and Prevcntiic Dcntistty, School of Deuital Medicine fooinded by the Alp/ia Omega Fraternitny Thf Hebretcc University-Hadassah Medical School, Jerusalem, Israel
J. RFISSTFIN,
I.
different grotips was determined by the ManrnWhitney U test. After both brushing periods with toothpaste, all the enamel surfaces were free of scratches, due possibly to the high hardness degree of enamel. The cementum surfaces exhibited scratches (fig), the nuimber increasing with the brushing period (Table) (P < 0.01). Brushing with saline was much1 less abrasive thanTI W.iI toothpaste (P < 0.001). This is in accord with the literature that the toothpaste is principally responsible for abrasiveness. at least on mtse of a soft tooth brush (BJORN. LsINLHE and GRONDAHL, Odoniol Revy 17: 109-120, 1966), as was the case in our experiment.
J Dent Bes 57(1 ):42 January 1978.
In the present study. the abrasion effect of enamel- and cementum-brushing with and without toothpaste was measuired by scanning electron microscopy. Twelve unerupted third molar teeth, extracted fronm human beings, 20 to 40 years old, were collected and stored in saline. From each tooth, 3 blocks, 4 X 7 mm, which included enamel and adjacent cementum areas, were cut under cooling with a carborundulm disk. Horizontal brushing of the outer enamel and cementum surfaces was performed with a dentifrice slurry (2 parts dentifrice to 1 part water). The tooth samples were fixed, 3 at a time. on a motor-driven rotating disk (100 rotations per minute). The tooth paste* used contained CaCO, as abrasive and the toothbrush was a soft nylon brandt The samples were allotted to 3 groups: 2 groups were brushed with the paste slurry for 5 and 10 minutes respectively. The third group was brIshed with saline for 10 minutes (control). SE micrographs (>X 100) of the brushed samples were divided into 100 squares, 1 X 1 cm. Counting of scratches was carried out in 10 squares, chosen at random, of the micrograph of the surfaces (GERDIN and SERENEKE, Scen/sk Tand Tids
65:191, 1972). No defects, which might have occurred during the extraction procedure of the teeth, were observed in unbrushed enamel and cementum samples prior to the brushing procedure as examined by the above described method. Statistical evaluation of the differences of the mean counts of scratches between the Received for publication September 7, 1977. Accepted for publication December 8, 1977. * Solidox, Itzhar, Nahalath Itzhak, Israel. Py-Co-Pay Softex Nylon.
FiG-Scanning electron micrograph of cementum brushed for 10 minutes with toothbrush and toothpaste. (Origmag x100.) TABLE
NUMBER OF SCRATCHES IN CENMENTUM FOLLOWJNcG ToorHBRUSHING Number of Scratches
With Toothpaste N timber of Samples 12 'p
42
C
With Saline
Brushing Period
10 Minutes
5 Minutes
Mlean 32.7
Range
0-56
Mean
50.1'
Range 29-61
10 Minutes Range
Mean 17.2x
0-35
0.001.
J Dent Res January 1978f Downloaded from jdr.sagepub.com at UNIV OF MICHIGAN on January 8, 2015 For personal use only. No other uses without permission.
J. RFISSTFIN,
I.
different grotips was determined by the ManrnWhitney U test. After both brushing periods with toothpaste, all the enamel surfaces were free of scratches, due possibly to the high hardness degree of enamel. The cementum surfaces exhibited scratches (fig), the nuimber increasing with the brushing period (Table) (P < 0.01). Brushing with saline was much1 less abrasive thanTI W.iI toothpaste (P < 0.001). This is in accord with the literature that the toothpaste is principally responsible for abrasiveness. at least on mtse of a soft tooth brush (BJORN. LsINLHE and GRONDAHL, Odoniol Revy 17: 109-120, 1966), as was the case in our experiment.
J Dent Bes 57(1 ):42 January 1978.
In the present study. the abrasion effect of enamel- and cementum-brushing with and without toothpaste was measuired by scanning electron microscopy. Twelve unerupted third molar teeth, extracted fronm human beings, 20 to 40 years old, were collected and stored in saline. From each tooth, 3 blocks, 4 X 7 mm, which included enamel and adjacent cementum areas, were cut under cooling with a carborundulm disk. Horizontal brushing of the outer enamel and cementum surfaces was performed with a dentifrice slurry (2 parts dentifrice to 1 part water). The tooth samples were fixed, 3 at a time. on a motor-driven rotating disk (100 rotations per minute). The tooth paste* used contained CaCO, as abrasive and the toothbrush was a soft nylon brandt The samples were allotted to 3 groups: 2 groups were brushed with the paste slurry for 5 and 10 minutes respectively. The third group was brIshed with saline for 10 minutes (control). SE micrographs (>X 100) of the brushed samples were divided into 100 squares, 1 X 1 cm. Counting of scratches was carried out in 10 squares, chosen at random, of the micrograph of the surfaces (GERDIN and SERENEKE, Scen/sk Tand Tids
65:191, 1972). No defects, which might have occurred during the extraction procedure of the teeth, were observed in unbrushed enamel and cementum samples prior to the brushing procedure as examined by the above described method. Statistical evaluation of the differences of the mean counts of scratches between the Received for publication September 7, 1977. Accepted for publication December 8, 1977. * Solidox, Itzhar, Nahalath Itzhak, Israel. Py-Co-Pay Softex Nylon.
FiG-Scanning electron micrograph of cementum brushed for 10 minutes with toothbrush and toothpaste. (Origmag x100.) TABLE
NUMBER OF SCRATCHES IN CENMENTUM FOLLOWJNcG ToorHBRUSHING Number of Scratches
With Toothpaste N timber of Samples 12 'p
42
C
With Saline
Brushing Period
10 Minutes
5 Minutes
Mlean 32.7
Range
0-56
Mean
50.1'
Range 29-61
10 Minutes Range
Mean 17.2x
0-35
0.001.
J Dent Res January 1978f Downloaded from jdr.sagepub.com at UNIV OF MICHIGAN on January 8, 2015 For personal use only. No other uses without permission.
