Scanning electron microscopic examination of ultrasonic and effervescent methods of surface contaminant removal from complete dentures Frank J. Raab, D.D.S.,* C. Ann Taylor, and Barbara L. Mann, Ph.D.**** Veterans’
Affairs
Medical
Center, Dayton,
Ph.D.,**
John
A. Bucher,
D.M.D.,***
Ohio
Dentures were examined by scanning electron microscopy to evaluate removal of surface contaminants such as plaque, calculus, microflora, and cigarette smoke. Ten complete dentures were obtained during patient appointments and prepared for SEM examination. Samples from 10 control surfaces, 10 surfaces cleaned with effervescent cleansers, and 10 surfaces ultrasonically cleaned were photographed at ~6000. One photograph of each sample was evaluated in random order by five judges for a total of 150 observations. Photographs were compared with one of a clean denture sample. Statistical analysis of the results validated the superiority of the ultrasonic method for cleaning dentures. (J PROSTAETDENT 1991;65:256-8.)
D enture hygiene has long been recognized as vital to the health of oral tissues. Methods for the physical removal of surface contaminants have included brushing with abrasive preparations, soaking dentures in effervescent solutions, and ultrasonic treatment. Physical removal in the form of brushing with abrasive scrub preparations has been demonstrated to be effective only when strict care is observed by the patient not to miss any denture surfaces.’ However, overzealous or improper use of abrasive techniques can result in damage to the denture. The bubbling action of effervescent solutions is purported to carry contaminants away from the denture surface. Ultrasonic cleaning is another form of physical removal. Plaque index studies evaluating the effectiveness of ultrasonic treatment report data varying from support of ultrasonic effectiveness,2 to finding it no more effective than effervescent-type cleaners,3 to disputing its effectiveness as a cleaning method.4 Recently, Gwinnett and Caputo5 used scanning electron microscopy (SEM) to evaluate surface plaque and microflora removal from finished dentures incubated in Streptococcus mutans. In their experiments, ultrasonic cleaning was more effective than effervescent methods in removing microorganisms from denture material, but their conclusions were limited by the in vitro nature of their study. In this clinical investigation, patients’ dentures were examined by SEM to evaluate removal of surface contami-
*Graduate
resident,
Department
of Periodontics,
University of Minn. **Electron microscopist, Department of Anatomy, Wright State University, School of Medicine, Dayton, Ohio. ***Staff prosthodontist, Dental Service (160). ****Associate Professor, Department of Mathematics and Statistics, Wright State University.
Minnesota, School of Dentistry, Minneapolis,
10/l/23200
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
nants such as plaque, calculus, microflora, and cigarette smoke. Comparisons were made between the efficacy of effervescent-type and ultrasonic cleaning methods.
MATERIAL
AND METHODS
Ten complete dentures were obtained from patients, and questionnaires were collected from each patient with each sample denture. Information was recorded concerning the manner and frequency of denture cleaning, age of the dentures, how the dentures were stored, and whether the patient smoked. The dentures collected were transferred directly from the patient’s mouth to 10% formalin. To examine any effects that fixation before cleaning might have, an additional set of samples stored in physiologic saline were prepared from one of the collected dentures and compared with the samples of the same denture stored in formalin. A Carborundum disk and high-speed lathe were used to prepare three samples from each collected denture. One specimen from each denture was left uncleaned to allow a basis for comparison of the two cleaning methods. The second specimen was cleaned with an effervescent denture cleaner (Extra Strength Efferdent; Warner-Lambert, Morris Plains, N.J.). Manufacturer’s directions were followed; dentures were soaked in the solution until bubbling ceased and solution cleared. The third specimen was placed in a 50 ml beaker of sterile water and then cleaned for 90 seconds in an L & R TransisterAJltrasonic T-28 cleaning unit (L dzR Mfg. Co., Irvine, Calif.). For additional comparison, a sample from a newly processed and polished piece of denture acrylic resin was also prepared. Each of the samples were dehydrated in a graded series of ethanol. Liquid carbon dioxide was used to “critical point” dry the samples, which were then luted to the electron microscope studs with silver paint. The samples were sputter-coated with gold/palladium by use of a Polaron E5100 coating unit (DuPont Co., Newtown, Conn.). Obser-
255
RAABETAL
Fig. 1. Newly processed and polished acrylic resin. (Original SEM X5000.)
Fig.
2. Untreated denture. (Original SEM X5000.)
Table I. Summary of mean values of judges’ scores Cleaning method
COl%KOl
Mean values
7.8
Effervescent
5.58
Ultrasonic 3.38
3. Denture cleaned by effervescence. (Original SEM X5000.)
Fig.
4. Denture cleaned by ultrasonics. (Original SEM X5000.)
Fig.
Table II. Source
Patient Treatment Judge
vations were made with a Phillips 500 scanning electron microscope (PhiUips Electronic Instruments, Mawah, NJ.). Photographs were made of representative regions of each sample at X80 and x5000 with Polaroid type 55 P/N film. The same region (lingual to the molars) of each denture was used for the photographs. Samples tram the 10 control surfaces, 10 surfaces cleaned with effervescent cleansers, and 10 surfaces cleaned in the ultrasonic unit were photographed at X5000. One photograph of each sample was evaluated in random order by five judges for a total of 150 observations. Each judge was given
Analysis of variance
Error TUt 8.1
df
9 2 4 134 149
Sum of squrrres
Mean
square
587.1733 65.2415 488.4133 244.2067 10.7733 2.6933 620.0133 4.6269 17Q6.3733
pValue
F
14.10 52.78 0.58
0.0001 0.0001 0.6761
a photograph of a clean denture surface (Fig. 1) for comparison. Photographs were graded on a scale from 1 (clean denture surface) to 10 based on the percent of sample area covered by foreign material. The judges did not know which method of cleaning the photographs represented. The analysis of variance (ANOVA) used was a three-way
FEBRUARY
Ieel
VOLUME
65
NUb%BRR
Z
SEM
STUDY
OF DENTURE
CLEANING
METHODS
Fig. 5. Denture stored in saIine before cleaning by effervescence. (Original SEM X5000.)
Fig. 6. Denture stored in saline before cleaning by ultrasonics. (Original SEM x5000.)
Fig. 7. Denture stored in formalin before cleaning by effervescence. (Original SEM X 500.)
Fig. 8. Denture stored in formalin before cleaning by ultrasonics. (Original SEM x 5000.)
cross-classification model with the three factors patients, judge, and treatment.
effectiveness of the ultrasonic method for cleaning the denture surface (Figs. 2 through 8). Whether the samples were stored in formalin or saline appeared to have no effect on the cleaning results (Figs. 5 through 8).
RESULTS The mean scores for the control group, the effervescent group, and the ultrasonic group are presented in Table I. The ultrasonic method scored better than the effervescent method in cleaning the denture surface. The ANOVA is presented in Table II. Treatments were significantly different from each other and from the controls, with a large F and p 0.0001. Tukey’s multiple comparison demonstrated that all three treatments were significantly different at o 0.05. Judges did not differ significantly with each other (p 0.0001). A residual analysis revealed no serious violations of the ANOVA assumptions. Photographs of representative regions demonstrated the
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
DISCUSSION Efficient cleaning of the denture surfaces is important in the maintenance of good oral hygiene for the denture patient. Traditionally, the denture wearer has used either effervescent cleaners or brushed the denture with use of a denture paste. Brushing combined with effervescent cleaning has not been found to reduce the level of recoverable microorganisms from denture surfaces.6 With an in vitro study, Palenick and Miller7 demonstrated the superiority of ultrasonic techniques over alkaline and peroxide immersion-type denture cleaners on denture surfaces with
257
RAAB ET AL
adherent plaque. The SEM examination in this study confirms previous reports that the ultrasonic method is the most effective technique for cleaning the denture surface.6*7 Ultrasonically cleaned samples achieved superior results in the removal of plaque, debris, and stains in most samples tested. Many handicapped patients, such as those who are debilitated by strokes, lack the physical dexte$ty to clean their dentures properly. The ultrasonic cleaning technique offers a rapid, inexpensive, effortless method of cleaning dentures for the handicapped patient. Whether ultrasonic cleaning methods can be more favorably used by all denture wearers needs to be verified by a more comprehensive clinical investigation.
Shannon IL, McCrary BR, Starcke EW. Removal of salivary deposits by commercial denture cleaners. Gen Dent 1976:24:30-A Myers HM, Krol AJ. Effectiveness of a sonic-action denture cleaning program. J PROSTHET DENT 1974;32:613-8. Budtz-Jorgensen E. Materials and methods for cleaning dentures.J ~7.
PROSTHET DENT 1979;42:619-23.
Gwinnett AJ, Caputo L. The effectiveness of ultrasonic denture cleaning: a scanning electron microscope study. J PROSTHET DENT 1983;
6
50~20-5. Dills SS, Olshan AM, Goldner S, Brogdon C. Comparison of the anti-
microbial capability of an abrasive paste and chemical-soak denture cleaners. J PROSTHET DENT 1988;60:467-70. 7. Palenik CJ, Miller CH. In vitro testing of three denture-cleaning systems. J PROSTHET DENT 1984;51:751-4. Reprint requests to: DR. FRANK RAAB 161 MCCARRON ST. 811 ROSEVILLE, MN 55113
REFERENCES 1. Lindquist L, Andrup B, Hedegard B. Proteshygien II. Klinisk vadering av ett hygienprogram for patienter med protessto mutitt. Tandlakartidningen 1975;61:872.
Cephalometrically predicted removable prosthodontics Hercules C. Karkazis, Dr. Dent., M.Sc.D.*
occlusal
D.D.S., Dr. Dent.,* and Gregory
plane: Implications
L. Polyzois,
in
D.D.S.,
University of Athens, School of Dentistry, Athens, Greece Although the determination of the occlusal plane is crucial in clinical removable prosthodontics, none of the existing methods gives su5cient guidelines for that purpose. The aim of this investigation was to check the hypothesis that the angulation of the occlusal plane is generally related to the skeletal base of the maxillae. Statistical analysis revealed (1) no strong linear correlation (p->O.OS) between the following variables: (a) the length of Cook’s plane to Cook’s occlusal plane angle, (b) the length of the maxillary plane to the maxillary occlusal plane angle, and (c) the PO Na AN6 angle to the occlusal Frankfort plane angle; (2) no parallelism between the occlusal and HIP plane with a mean angle of 4.57 degrees, SD 2.57 degrees, and range of 0 to 9.5 degrees; and (3) no correlation between the predicted and clinically determined occlusal planes (r0.267, t1.797, p 70.05). (J PROSTHET DENT 1991;65:258-64.
T
he function and esthetics of removable prostheses are dependent on the correct orientation of the occlusal plane. Many theories and methods have been proposed over the years to facilitate correlation of the artificial occlusal plane to the natural 0ne.l Lateral cephalometric radiography has been used for the study of the relationships between the natural occlusal
Presented at the European Prosthodontic Association meeting, Oslo, Norway. *Assistant Professor, Department of Prosthodontics. 10/l/22689
258
plane and other cranial landmarks2 and recently for prediction of the occlusal plane orientation in complete and partial denture fabrication.3-5 However, none of these methods provides evidence for widespread clinical application. The objective of this investigation was to check the hypothesis that the angulation
of the occlusal plane is gener-
ally related to the skeletal base of the maxillae. An attempt was made to: 1. Study the relationship between the length of Cook’s plane running from the anterior nasal spine (ANS) to the hamular notch (HN) and the angulation of the occlusal plane relative to Cook’s plane; 2. Explore the possible correlation between the length of
FEBRUARY
lBB1
VOLUME
66
NUMBER
2
Affairs
Medical
Center, Dayton,
Ph.D.,**
John
A. Bucher,
D.M.D.,***
Ohio
Dentures were examined by scanning electron microscopy to evaluate removal of surface contaminants such as plaque, calculus, microflora, and cigarette smoke. Ten complete dentures were obtained during patient appointments and prepared for SEM examination. Samples from 10 control surfaces, 10 surfaces cleaned with effervescent cleansers, and 10 surfaces ultrasonically cleaned were photographed at ~6000. One photograph of each sample was evaluated in random order by five judges for a total of 150 observations. Photographs were compared with one of a clean denture sample. Statistical analysis of the results validated the superiority of the ultrasonic method for cleaning dentures. (J PROSTAETDENT 1991;65:256-8.)
D enture hygiene has long been recognized as vital to the health of oral tissues. Methods for the physical removal of surface contaminants have included brushing with abrasive preparations, soaking dentures in effervescent solutions, and ultrasonic treatment. Physical removal in the form of brushing with abrasive scrub preparations has been demonstrated to be effective only when strict care is observed by the patient not to miss any denture surfaces.’ However, overzealous or improper use of abrasive techniques can result in damage to the denture. The bubbling action of effervescent solutions is purported to carry contaminants away from the denture surface. Ultrasonic cleaning is another form of physical removal. Plaque index studies evaluating the effectiveness of ultrasonic treatment report data varying from support of ultrasonic effectiveness,2 to finding it no more effective than effervescent-type cleaners,3 to disputing its effectiveness as a cleaning method.4 Recently, Gwinnett and Caputo5 used scanning electron microscopy (SEM) to evaluate surface plaque and microflora removal from finished dentures incubated in Streptococcus mutans. In their experiments, ultrasonic cleaning was more effective than effervescent methods in removing microorganisms from denture material, but their conclusions were limited by the in vitro nature of their study. In this clinical investigation, patients’ dentures were examined by SEM to evaluate removal of surface contami-
*Graduate
resident,
Department
of Periodontics,
University of Minn. **Electron microscopist, Department of Anatomy, Wright State University, School of Medicine, Dayton, Ohio. ***Staff prosthodontist, Dental Service (160). ****Associate Professor, Department of Mathematics and Statistics, Wright State University.
Minnesota, School of Dentistry, Minneapolis,
10/l/23200
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
nants such as plaque, calculus, microflora, and cigarette smoke. Comparisons were made between the efficacy of effervescent-type and ultrasonic cleaning methods.
MATERIAL
AND METHODS
Ten complete dentures were obtained from patients, and questionnaires were collected from each patient with each sample denture. Information was recorded concerning the manner and frequency of denture cleaning, age of the dentures, how the dentures were stored, and whether the patient smoked. The dentures collected were transferred directly from the patient’s mouth to 10% formalin. To examine any effects that fixation before cleaning might have, an additional set of samples stored in physiologic saline were prepared from one of the collected dentures and compared with the samples of the same denture stored in formalin. A Carborundum disk and high-speed lathe were used to prepare three samples from each collected denture. One specimen from each denture was left uncleaned to allow a basis for comparison of the two cleaning methods. The second specimen was cleaned with an effervescent denture cleaner (Extra Strength Efferdent; Warner-Lambert, Morris Plains, N.J.). Manufacturer’s directions were followed; dentures were soaked in the solution until bubbling ceased and solution cleared. The third specimen was placed in a 50 ml beaker of sterile water and then cleaned for 90 seconds in an L & R TransisterAJltrasonic T-28 cleaning unit (L dzR Mfg. Co., Irvine, Calif.). For additional comparison, a sample from a newly processed and polished piece of denture acrylic resin was also prepared. Each of the samples were dehydrated in a graded series of ethanol. Liquid carbon dioxide was used to “critical point” dry the samples, which were then luted to the electron microscope studs with silver paint. The samples were sputter-coated with gold/palladium by use of a Polaron E5100 coating unit (DuPont Co., Newtown, Conn.). Obser-
255
RAABETAL
Fig. 1. Newly processed and polished acrylic resin. (Original SEM X5000.)
Fig.
2. Untreated denture. (Original SEM X5000.)
Table I. Summary of mean values of judges’ scores Cleaning method
COl%KOl
Mean values
7.8
Effervescent
5.58
Ultrasonic 3.38
3. Denture cleaned by effervescence. (Original SEM X5000.)
Fig.
4. Denture cleaned by ultrasonics. (Original SEM X5000.)
Fig.
Table II. Source
Patient Treatment Judge
vations were made with a Phillips 500 scanning electron microscope (PhiUips Electronic Instruments, Mawah, NJ.). Photographs were made of representative regions of each sample at X80 and x5000 with Polaroid type 55 P/N film. The same region (lingual to the molars) of each denture was used for the photographs. Samples tram the 10 control surfaces, 10 surfaces cleaned with effervescent cleansers, and 10 surfaces cleaned in the ultrasonic unit were photographed at X5000. One photograph of each sample was evaluated in random order by five judges for a total of 150 observations. Each judge was given
Analysis of variance
Error TUt 8.1
df
9 2 4 134 149
Sum of squrrres
Mean
square
587.1733 65.2415 488.4133 244.2067 10.7733 2.6933 620.0133 4.6269 17Q6.3733
pValue
F
14.10 52.78 0.58
0.0001 0.0001 0.6761
a photograph of a clean denture surface (Fig. 1) for comparison. Photographs were graded on a scale from 1 (clean denture surface) to 10 based on the percent of sample area covered by foreign material. The judges did not know which method of cleaning the photographs represented. The analysis of variance (ANOVA) used was a three-way
FEBRUARY
Ieel
VOLUME
65
NUb%BRR
Z
SEM
STUDY
OF DENTURE
CLEANING
METHODS
Fig. 5. Denture stored in saIine before cleaning by effervescence. (Original SEM X5000.)
Fig. 6. Denture stored in saline before cleaning by ultrasonics. (Original SEM x5000.)
Fig. 7. Denture stored in formalin before cleaning by effervescence. (Original SEM X 500.)
Fig. 8. Denture stored in formalin before cleaning by ultrasonics. (Original SEM x 5000.)
cross-classification model with the three factors patients, judge, and treatment.
effectiveness of the ultrasonic method for cleaning the denture surface (Figs. 2 through 8). Whether the samples were stored in formalin or saline appeared to have no effect on the cleaning results (Figs. 5 through 8).
RESULTS The mean scores for the control group, the effervescent group, and the ultrasonic group are presented in Table I. The ultrasonic method scored better than the effervescent method in cleaning the denture surface. The ANOVA is presented in Table II. Treatments were significantly different from each other and from the controls, with a large F and p 0.0001. Tukey’s multiple comparison demonstrated that all three treatments were significantly different at o 0.05. Judges did not differ significantly with each other (p 0.0001). A residual analysis revealed no serious violations of the ANOVA assumptions. Photographs of representative regions demonstrated the
THE
JOURNAL
OF PROSTHETIC
DENTISTRY
DISCUSSION Efficient cleaning of the denture surfaces is important in the maintenance of good oral hygiene for the denture patient. Traditionally, the denture wearer has used either effervescent cleaners or brushed the denture with use of a denture paste. Brushing combined with effervescent cleaning has not been found to reduce the level of recoverable microorganisms from denture surfaces.6 With an in vitro study, Palenick and Miller7 demonstrated the superiority of ultrasonic techniques over alkaline and peroxide immersion-type denture cleaners on denture surfaces with
257
RAAB ET AL
adherent plaque. The SEM examination in this study confirms previous reports that the ultrasonic method is the most effective technique for cleaning the denture surface.6*7 Ultrasonically cleaned samples achieved superior results in the removal of plaque, debris, and stains in most samples tested. Many handicapped patients, such as those who are debilitated by strokes, lack the physical dexte$ty to clean their dentures properly. The ultrasonic cleaning technique offers a rapid, inexpensive, effortless method of cleaning dentures for the handicapped patient. Whether ultrasonic cleaning methods can be more favorably used by all denture wearers needs to be verified by a more comprehensive clinical investigation.
Shannon IL, McCrary BR, Starcke EW. Removal of salivary deposits by commercial denture cleaners. Gen Dent 1976:24:30-A Myers HM, Krol AJ. Effectiveness of a sonic-action denture cleaning program. J PROSTHET DENT 1974;32:613-8. Budtz-Jorgensen E. Materials and methods for cleaning dentures.J ~7.
PROSTHET DENT 1979;42:619-23.
Gwinnett AJ, Caputo L. The effectiveness of ultrasonic denture cleaning: a scanning electron microscope study. J PROSTHET DENT 1983;
6
50~20-5. Dills SS, Olshan AM, Goldner S, Brogdon C. Comparison of the anti-
microbial capability of an abrasive paste and chemical-soak denture cleaners. J PROSTHET DENT 1988;60:467-70. 7. Palenik CJ, Miller CH. In vitro testing of three denture-cleaning systems. J PROSTHET DENT 1984;51:751-4. Reprint requests to: DR. FRANK RAAB 161 MCCARRON ST. 811 ROSEVILLE, MN 55113
REFERENCES 1. Lindquist L, Andrup B, Hedegard B. Proteshygien II. Klinisk vadering av ett hygienprogram for patienter med protessto mutitt. Tandlakartidningen 1975;61:872.
Cephalometrically predicted removable prosthodontics Hercules C. Karkazis, Dr. Dent., M.Sc.D.*
occlusal
D.D.S., Dr. Dent.,* and Gregory
plane: Implications
L. Polyzois,
in
D.D.S.,
University of Athens, School of Dentistry, Athens, Greece Although the determination of the occlusal plane is crucial in clinical removable prosthodontics, none of the existing methods gives su5cient guidelines for that purpose. The aim of this investigation was to check the hypothesis that the angulation of the occlusal plane is generally related to the skeletal base of the maxillae. Statistical analysis revealed (1) no strong linear correlation (p->O.OS) between the following variables: (a) the length of Cook’s plane to Cook’s occlusal plane angle, (b) the length of the maxillary plane to the maxillary occlusal plane angle, and (c) the PO Na AN6 angle to the occlusal Frankfort plane angle; (2) no parallelism between the occlusal and HIP plane with a mean angle of 4.57 degrees, SD 2.57 degrees, and range of 0 to 9.5 degrees; and (3) no correlation between the predicted and clinically determined occlusal planes (r0.267, t1.797, p 70.05). (J PROSTHET DENT 1991;65:258-64.
T
he function and esthetics of removable prostheses are dependent on the correct orientation of the occlusal plane. Many theories and methods have been proposed over the years to facilitate correlation of the artificial occlusal plane to the natural 0ne.l Lateral cephalometric radiography has been used for the study of the relationships between the natural occlusal
Presented at the European Prosthodontic Association meeting, Oslo, Norway. *Assistant Professor, Department of Prosthodontics. 10/l/22689
258
plane and other cranial landmarks2 and recently for prediction of the occlusal plane orientation in complete and partial denture fabrication.3-5 However, none of these methods provides evidence for widespread clinical application. The objective of this investigation was to check the hypothesis that the angulation
of the occlusal plane is gener-
ally related to the skeletal base of the maxillae. An attempt was made to: 1. Study the relationship between the length of Cook’s plane running from the anterior nasal spine (ANS) to the hamular notch (HN) and the angulation of the occlusal plane relative to Cook’s plane; 2. Explore the possible correlation between the length of
FEBRUARY
lBB1
VOLUME
66
NUMBER
2
