- Email: [email protected]
Caries detection
INQUIRY Dental Caries Caries detection Background.—Dental practitioners’ most important role is to help patients control their caries situation. Dentists have the expertise to detect caries lesions before they produce symptoms. The patient may visit the dentist’s office for a regular dental checkup or for a problem. During the visit the practitioner conducts a dental examination of the oral mucosa, periodontium, and teeth. Caries lesions that require treatment are detected through a careful visual-tactile inspection. Each tooth surface is evaluated according to a standardized, sequential pattern, noting deviations from normal appearance (color, luster, surface texture, and surface integrity). Because of the repetitiveness of this process, the diagnostic process becomes a ‘‘pattern-recognition’’ process and the teeth are scanned
for similarity to a set of clinical patterns or ‘‘caries scripts’’ representing the clinician’s cumulative experience with clinical patterns. When a matching caries script is identified, a corresponding treatment is selected, bypassing diagnostic considerations. If no matching script is identified, the clinician collects more data using ancillary diagnostic devices, most often bite-wing radiographs. The question that arises is whether caries-related treatment decisions lead to the best course of action. The process was dissected and evaluated for its appropriateness. Caries Detection and Management.—Caries-related treatment decisions are influenced by patient factors and dentist factors, which are the elements that produce the
Fig 1.—Conceptual model explaining how dentists make caries-related treatment decisions. Adapted from Bader & Shugars [14]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
258
Dental Abstracts
Table 1.—Diagnostic Results Obtained When Applying Bitewing Radiography (BW) for the Detection of Approximal Cavities in a Population of 10,000 Approximal Surfaces. Given for Different Values of the True, But Unknown, Prevalence of Approximal Cavitation. Sensitivity = 66%, Specificity = 95% [71] Cavity prevalence (n = 10,000) (%)
0.1 0.5 1 2.5 5
No. of BWD cavities
No. of BW– cavities
Total no. of cavities
No. of BWD intact surfaces
No. of BW– intact surfaces
Total no. of intact surfaces
6.6 33 66 165 330
3.4 17 34 85 170
10 50 100 250 500
585 497 495 487 475
9405 9453 9405 9263 9025
9990 9950 9900 9750 9500
(Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
dentist’s stock of caries scripts (Fig 1). Dentist factors can be altered through dental education and through the influence of experienced dental practitioners. Established practitioners are, however, unlikely to change how they detect caries unless a single professional standard is developed that eliminates the need for subjective interpretation and serves the public. Improved caries-related decisions rely on (1) the caries– lesion treatment options available and (2) matching treatment options to the caries lesions seen. Treatment may be operative or nonoperative. Cavitated lesions require restoration so the tooth surface is easier to clean and the pulpodentinal complex is protected. Treatment can halt the progression of cavitated lesions that are accessible to daily hygiene, so a highly motivated patient can be offered nonoperative treatment. Noncavitated lesions can be arrested or active. Nonoperative procedures can arrest noncavitated lesions, making further treatment unnecessary. Active noncavitated caries lesions are therefore addressed with the goal of arresting the process and achieving a good prognosis. The visual-tactile caries lesion detection methods are the only way to distinguish cavitated from noncavitated lesions and arrested from active lesions. Adding bite-wing radiographs reveals lesion depth but does not indicate surface integrity or activity status data. The sensitivity and specificity of bite-wing radiographs in detecting approximal
caries are 0.66 and 0.95, respectively (Table 1). If the 1% true cavity prevalence is chosen as an example, and a clinician restores all of the surfaces that are positive on bite-wing radiographs, Table 1 shows that 561 surfaces would be restored, but 88% of these would have been unnecessary and constitute overtreatment. If one considers true cavities, 34% would not be diagnosed and go untreated. Thus 529 decisional errors would be committed by relying on bite-wing radiographs. In contrast, the visual-tactile examination has a sensitivity and specificity of 0.52 and 0.98, respectively (Table 2). If the 1% true cavity prevalence is used, 250 surfaces positive on bite-wing radiographs would be restored, but 79% would have been unnecessary and 48 would be undiagnosed. A total of 246 decisional errors would be made, less than half of the number made by relying on bite-wing radiographs. So although bite-wing radiographs add information, they actually result in substantially more invasive treatment recommendations, more overtreatment, and fewer correct treatment recommendations. Adding together tests that have a low but discernible error probability produces more diagnostic and decisional errors. Regular Checkups.—The principles underlying the practice of participating in regular checkup visits or routine recall programs can be charted (Fig 2). During a routine checkup visit, dentists can detect caries lesions before patients would have noticed them. Treatment gives the tooth a longer lifespan compared to waiting until the damage was noted by the patient. However, detecting the caries lesion
Table 2.—Diagnostic Results Obtained When Applying Visual-Tactile (VT) Methods for the Detection of Approximal Cavities in a Population of 10,000 Approximal Surfaces. Given for Different Values of the True, But Unknown, Prevalence of Approximal Cavitation. Sensitivity = 52%, Specificity = 98% [71] Cavity prevalence (n = 10,000) (%)
0.1 0.5 1 2.5 5
No. of VTD cavities
No. of VT– cavities
Total no. of cavities
No. of VTD intact surfaces
No. of VT– intact surfaces
Total no. of intact surfaces
5.2 26 52 130 260
4.8 24 48 120 240
10 50 100 250 500
200 199 198 195 190
9790 9751 9702 9555 9310
9990 9950 9900 9750 9500
(Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
Volume 55
Issue 5
2010
259
Fig 2.—The principles underlining screening: three possible scenarios depending on earlier disease detection and treatment effect. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
earlier does not benefit the patient unless the treatment postpones an extraction or similar invasive procedure. The ‘‘longer survival time’’ simply reflects earlier detection, called lead-time bias. The dentist claims that regular dental checkups benefit the patient by providing better oral health conditions than
would be present without the checkups. However, evidence of a beneficial effect has not been obtained, principally because the current studies are observational rather than randomized controlled clinical trials. Dentists do not acknowledge that routine recall or checkup visits can also cause harm, just as any other screening program can. Patients should be informed of both the benefits and the
Fig 3.—Development over three decades in the dft/DFT counts among Swedes aged 10 to 80 years. Data from Huguson et al [165]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
Fig 4.—Development over three decades in the number of natural teeth present among Swedes aged 10 to 80 years. Data from Huguson et al [165]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
260
Dental Abstracts
Fig 5.—Changes in the propensity of dentists in the Norwegian Dental Public Service to restore approximal surfaces among 15year-olds as a function of the radiographic finding and the year of examination. Data from Gimmestad et al [166]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
hazards of these screenings so they can decide whether or not to attend. It is important to be open and fair about both the intended and the unintended consequences of participating in any program of recall visits to ensure informed consent. Professionalism.—Dentists generally control the demand for and use of dental services. If screening visits are not needed or used for selfish purposes, patients should be so informed. Most patients do not have the knowledge or expertise to review the dentist’s performance and evaluate the need for and quality of the work provided. Dentists and patients essentially enter into a social contract that implies that professionals are committed to being competent persons of integrity, morality, and altruism who have the promotion of the public’s good at heart. To maintain its status as a profession, dentistry must also maintain the public’s trust that the dentist is working for their good and will not exploit the dental monopoly or the patient’s vulnerability. It must be recognized that dentists derive their personal income from providing services to the public, giving a basis for a conflict of interest. A problem is developing as dentists exercise more commercialism and include elective treatments such as cosmetic procedures as a greater proportion of the total volume of dental services provided, although they are not indicated for dental health per se. To counter this commercialism, states or insurance companies may impose more rules and regulations or codes of conduct and ethics
Fig 6.—Changes in the propensity of dentists in the Danish Dental Public Service to restore approximal surfaces among 17-year-olds as a function of the radiographic finding and the year of examination. Data from Heidmann et al [167]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
on dentists. The heart of what professionalism must defend is the economic privilege that follows from dentistry’s monopoly over its knowledge base. Unless current trends change, dental professionals will become servants providing for the needs of the state, which will dictate performance and costs. Professional status is delegated to a discipline by the state and cannot be achieved unless the state is convinced that the discipline is of value to the public or to a vital state interest. Delegation is totally based on trust. Reinforcement of the institutional ethics that deal with the economic, political, social, and ideological circumstances that create the moral dilemmas associated with work is essential. For dentistry to survive as a profession, the dental associations must organize to ensure a disciplinary dental practice that exercises responsible and accountable discretion in making decisions, which should be evidence based. Systems to enforce the detailed codes of practice ethics are needed. The public should see dentistry serving as their advocate when dental practitioners abuse their privileged position for selfish reasons. Another challenge facing dentistry regarding professionalism involves current developments in oral disease patterns. Epidemiologic evidence clearly shows that the population prevalence, extent, and severity of dental caries have fallen significantly in most populations and in diverse populations. In addition, tooth retention among older persons, who traditionally have pronounced tooth loss, has improved. The age at which the decayed or filled deciduous teeth/permanent teeth (dft/DFT) experience peaks has
Volume 55
Issue 5
2010
261
increased from 30 years to 60 years (Fig 3). Tooth retention among 60- to 80-year-olds has increased (Fig 4). In addition, the progression of caries has declined substantially. These dramatic, widespread improvements should be observed to see if there are parallel changes in the dental services given to the public. Increasingly, dentists should be offering nonperative, and less profitable, caries management procedures. Restorative treatments should gradually disappear from the dentist’s armamentarium if this trend continues. Considering data from Norway and Denmark, cariesrelated treatment practices offered by dentists employed in public dental services have changed (Figs 5 and 6). The responsiveness of these public entities is in contrast to the wishes of private dental services to maintain a high income while working a reasonable number of hours. The profession must choose between the commercial way, making itself a for-profit business, and the professional healthcare-oriented way, serving the public adequately and ethically in relation to altered population disease profiles.
Clinical Significance.—The evidence indicates that it is time to rely more on a diligently performed clinical visual-tactile caries examination and phase out the use of unneeded bitewing radiographs and other diagnostic methods to detect additional caries lesions. The assessment of lesion activity and surface integrity is the key to identifying lesions that can be treated according to biologically and ethically sound principles. The International Caries Detection and Assessment System (ICDAS) was developed for researchers and epidemiologists and has limited applicability to the dental practice setting. The Nyvad criteria, however, are simple to use and provide a direct relationship between clinical presentation and optimal treatment options. The criteria are a good fit for the caries script matching approach to caries detection used daily by dental clinicians. The best caries diagnostic test is that which serves patients by ensuring the best long-term oral health outcomes. Randomized controlled clinical trials are needed to clearly define which method of detecting caries lesions is best.
Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010 Reprints available from V Baelum, Dept of Epidemiology, School of Public Health, Aarhus Univ, Bartholins Alle 2, DK-8000 Aarhus C, Denmark; e-mail: [email protected]
Dental Education Chinese and North American dentistry Background.—There is little information available that outlines the dental education and professional development of dentists in various countries. Such knowledge would be helpful in promoting international activities among practicing dentists worldwide. The differences in dental education and professional development between North America and mainland China were evaluated along with the consequences of the approaches.
In mainland China, all dental schools are publicly funded. North American dental schools can be public universities, private schools with no direct state funding, or private but state-related, receiving a per capita enrollment subsidy from the state. The basic 5-year program in China costs about US $5000. Graduates of a 4-year public dental program in the United States average $105,000 and private school graduates $118,000.
Educational Model.—Chinese dental schools use a research-based stomatologic approach for their educational model. The schools are organized into departments and associated clinics. The dental school and research institution are considered a single entity. In contrast, for most North American dental schools an affiliated faculty/ school is associated with a university. The faculty is an independent unit within the university, and dentistry is considered a specialty area of medicine.
The dental programs in mainland China offer a 5-year baccalaureate degree conferred on undergraduate medical and dental students (Bachelor of Dental Surgery, BDS), a 7-year masters degree after BDS training with 2 years of graduate training (Master of Dental Surgery, MDS), or an 8-year doctor’s degree that adds 3 years onto the BDS program (Doctor of Dental Surgery, DDS). Typically the 4-year dental school curriculum in North America consists of basic science and preclinical instruction for 2 years plus
262
Dental Abstracts
for similarity to a set of clinical patterns or ‘‘caries scripts’’ representing the clinician’s cumulative experience with clinical patterns. When a matching caries script is identified, a corresponding treatment is selected, bypassing diagnostic considerations. If no matching script is identified, the clinician collects more data using ancillary diagnostic devices, most often bite-wing radiographs. The question that arises is whether caries-related treatment decisions lead to the best course of action. The process was dissected and evaluated for its appropriateness. Caries Detection and Management.—Caries-related treatment decisions are influenced by patient factors and dentist factors, which are the elements that produce the
Fig 1.—Conceptual model explaining how dentists make caries-related treatment decisions. Adapted from Bader & Shugars [14]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
258
Dental Abstracts
Table 1.—Diagnostic Results Obtained When Applying Bitewing Radiography (BW) for the Detection of Approximal Cavities in a Population of 10,000 Approximal Surfaces. Given for Different Values of the True, But Unknown, Prevalence of Approximal Cavitation. Sensitivity = 66%, Specificity = 95% [71] Cavity prevalence (n = 10,000) (%)
0.1 0.5 1 2.5 5
No. of BWD cavities
No. of BW– cavities
Total no. of cavities
No. of BWD intact surfaces
No. of BW– intact surfaces
Total no. of intact surfaces
6.6 33 66 165 330
3.4 17 34 85 170
10 50 100 250 500
585 497 495 487 475
9405 9453 9405 9263 9025
9990 9950 9900 9750 9500
(Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
dentist’s stock of caries scripts (Fig 1). Dentist factors can be altered through dental education and through the influence of experienced dental practitioners. Established practitioners are, however, unlikely to change how they detect caries unless a single professional standard is developed that eliminates the need for subjective interpretation and serves the public. Improved caries-related decisions rely on (1) the caries– lesion treatment options available and (2) matching treatment options to the caries lesions seen. Treatment may be operative or nonoperative. Cavitated lesions require restoration so the tooth surface is easier to clean and the pulpodentinal complex is protected. Treatment can halt the progression of cavitated lesions that are accessible to daily hygiene, so a highly motivated patient can be offered nonoperative treatment. Noncavitated lesions can be arrested or active. Nonoperative procedures can arrest noncavitated lesions, making further treatment unnecessary. Active noncavitated caries lesions are therefore addressed with the goal of arresting the process and achieving a good prognosis. The visual-tactile caries lesion detection methods are the only way to distinguish cavitated from noncavitated lesions and arrested from active lesions. Adding bite-wing radiographs reveals lesion depth but does not indicate surface integrity or activity status data. The sensitivity and specificity of bite-wing radiographs in detecting approximal
caries are 0.66 and 0.95, respectively (Table 1). If the 1% true cavity prevalence is chosen as an example, and a clinician restores all of the surfaces that are positive on bite-wing radiographs, Table 1 shows that 561 surfaces would be restored, but 88% of these would have been unnecessary and constitute overtreatment. If one considers true cavities, 34% would not be diagnosed and go untreated. Thus 529 decisional errors would be committed by relying on bite-wing radiographs. In contrast, the visual-tactile examination has a sensitivity and specificity of 0.52 and 0.98, respectively (Table 2). If the 1% true cavity prevalence is used, 250 surfaces positive on bite-wing radiographs would be restored, but 79% would have been unnecessary and 48 would be undiagnosed. A total of 246 decisional errors would be made, less than half of the number made by relying on bite-wing radiographs. So although bite-wing radiographs add information, they actually result in substantially more invasive treatment recommendations, more overtreatment, and fewer correct treatment recommendations. Adding together tests that have a low but discernible error probability produces more diagnostic and decisional errors. Regular Checkups.—The principles underlying the practice of participating in regular checkup visits or routine recall programs can be charted (Fig 2). During a routine checkup visit, dentists can detect caries lesions before patients would have noticed them. Treatment gives the tooth a longer lifespan compared to waiting until the damage was noted by the patient. However, detecting the caries lesion
Table 2.—Diagnostic Results Obtained When Applying Visual-Tactile (VT) Methods for the Detection of Approximal Cavities in a Population of 10,000 Approximal Surfaces. Given for Different Values of the True, But Unknown, Prevalence of Approximal Cavitation. Sensitivity = 52%, Specificity = 98% [71] Cavity prevalence (n = 10,000) (%)
0.1 0.5 1 2.5 5
No. of VTD cavities
No. of VT– cavities
Total no. of cavities
No. of VTD intact surfaces
No. of VT– intact surfaces
Total no. of intact surfaces
5.2 26 52 130 260
4.8 24 48 120 240
10 50 100 250 500
200 199 198 195 190
9790 9751 9702 9555 9310
9990 9950 9900 9750 9500
(Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
Volume 55
Issue 5
2010
259
Fig 2.—The principles underlining screening: three possible scenarios depending on earlier disease detection and treatment effect. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
earlier does not benefit the patient unless the treatment postpones an extraction or similar invasive procedure. The ‘‘longer survival time’’ simply reflects earlier detection, called lead-time bias. The dentist claims that regular dental checkups benefit the patient by providing better oral health conditions than
would be present without the checkups. However, evidence of a beneficial effect has not been obtained, principally because the current studies are observational rather than randomized controlled clinical trials. Dentists do not acknowledge that routine recall or checkup visits can also cause harm, just as any other screening program can. Patients should be informed of both the benefits and the
Fig 3.—Development over three decades in the dft/DFT counts among Swedes aged 10 to 80 years. Data from Huguson et al [165]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
Fig 4.—Development over three decades in the number of natural teeth present among Swedes aged 10 to 80 years. Data from Huguson et al [165]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
260
Dental Abstracts
Fig 5.—Changes in the propensity of dentists in the Norwegian Dental Public Service to restore approximal surfaces among 15year-olds as a function of the radiographic finding and the year of examination. Data from Gimmestad et al [166]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
hazards of these screenings so they can decide whether or not to attend. It is important to be open and fair about both the intended and the unintended consequences of participating in any program of recall visits to ensure informed consent. Professionalism.—Dentists generally control the demand for and use of dental services. If screening visits are not needed or used for selfish purposes, patients should be so informed. Most patients do not have the knowledge or expertise to review the dentist’s performance and evaluate the need for and quality of the work provided. Dentists and patients essentially enter into a social contract that implies that professionals are committed to being competent persons of integrity, morality, and altruism who have the promotion of the public’s good at heart. To maintain its status as a profession, dentistry must also maintain the public’s trust that the dentist is working for their good and will not exploit the dental monopoly or the patient’s vulnerability. It must be recognized that dentists derive their personal income from providing services to the public, giving a basis for a conflict of interest. A problem is developing as dentists exercise more commercialism and include elective treatments such as cosmetic procedures as a greater proportion of the total volume of dental services provided, although they are not indicated for dental health per se. To counter this commercialism, states or insurance companies may impose more rules and regulations or codes of conduct and ethics
Fig 6.—Changes in the propensity of dentists in the Danish Dental Public Service to restore approximal surfaces among 17-year-olds as a function of the radiographic finding and the year of examination. Data from Heidmann et al [167]. (Courtesy of Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010.)
on dentists. The heart of what professionalism must defend is the economic privilege that follows from dentistry’s monopoly over its knowledge base. Unless current trends change, dental professionals will become servants providing for the needs of the state, which will dictate performance and costs. Professional status is delegated to a discipline by the state and cannot be achieved unless the state is convinced that the discipline is of value to the public or to a vital state interest. Delegation is totally based on trust. Reinforcement of the institutional ethics that deal with the economic, political, social, and ideological circumstances that create the moral dilemmas associated with work is essential. For dentistry to survive as a profession, the dental associations must organize to ensure a disciplinary dental practice that exercises responsible and accountable discretion in making decisions, which should be evidence based. Systems to enforce the detailed codes of practice ethics are needed. The public should see dentistry serving as their advocate when dental practitioners abuse their privileged position for selfish reasons. Another challenge facing dentistry regarding professionalism involves current developments in oral disease patterns. Epidemiologic evidence clearly shows that the population prevalence, extent, and severity of dental caries have fallen significantly in most populations and in diverse populations. In addition, tooth retention among older persons, who traditionally have pronounced tooth loss, has improved. The age at which the decayed or filled deciduous teeth/permanent teeth (dft/DFT) experience peaks has
Volume 55
Issue 5
2010
261
increased from 30 years to 60 years (Fig 3). Tooth retention among 60- to 80-year-olds has increased (Fig 4). In addition, the progression of caries has declined substantially. These dramatic, widespread improvements should be observed to see if there are parallel changes in the dental services given to the public. Increasingly, dentists should be offering nonperative, and less profitable, caries management procedures. Restorative treatments should gradually disappear from the dentist’s armamentarium if this trend continues. Considering data from Norway and Denmark, cariesrelated treatment practices offered by dentists employed in public dental services have changed (Figs 5 and 6). The responsiveness of these public entities is in contrast to the wishes of private dental services to maintain a high income while working a reasonable number of hours. The profession must choose between the commercial way, making itself a for-profit business, and the professional healthcare-oriented way, serving the public adequately and ethically in relation to altered population disease profiles.
Clinical Significance.—The evidence indicates that it is time to rely more on a diligently performed clinical visual-tactile caries examination and phase out the use of unneeded bitewing radiographs and other diagnostic methods to detect additional caries lesions. The assessment of lesion activity and surface integrity is the key to identifying lesions that can be treated according to biologically and ethically sound principles. The International Caries Detection and Assessment System (ICDAS) was developed for researchers and epidemiologists and has limited applicability to the dental practice setting. The Nyvad criteria, however, are simple to use and provide a direct relationship between clinical presentation and optimal treatment options. The criteria are a good fit for the caries script matching approach to caries detection used daily by dental clinicians. The best caries diagnostic test is that which serves patients by ensuring the best long-term oral health outcomes. Randomized controlled clinical trials are needed to clearly define which method of detecting caries lesions is best.
Baelum V: What is an appropriate caries diagnosis? Acta Odontol Scand 68:65-79, 2010 Reprints available from V Baelum, Dept of Epidemiology, School of Public Health, Aarhus Univ, Bartholins Alle 2, DK-8000 Aarhus C, Denmark; e-mail: [email protected]
Dental Education Chinese and North American dentistry Background.—There is little information available that outlines the dental education and professional development of dentists in various countries. Such knowledge would be helpful in promoting international activities among practicing dentists worldwide. The differences in dental education and professional development between North America and mainland China were evaluated along with the consequences of the approaches.
In mainland China, all dental schools are publicly funded. North American dental schools can be public universities, private schools with no direct state funding, or private but state-related, receiving a per capita enrollment subsidy from the state. The basic 5-year program in China costs about US $5000. Graduates of a 4-year public dental program in the United States average $105,000 and private school graduates $118,000.
Educational Model.—Chinese dental schools use a research-based stomatologic approach for their educational model. The schools are organized into departments and associated clinics. The dental school and research institution are considered a single entity. In contrast, for most North American dental schools an affiliated faculty/ school is associated with a university. The faculty is an independent unit within the university, and dentistry is considered a specialty area of medicine.
The dental programs in mainland China offer a 5-year baccalaureate degree conferred on undergraduate medical and dental students (Bachelor of Dental Surgery, BDS), a 7-year masters degree after BDS training with 2 years of graduate training (Master of Dental Surgery, MDS), or an 8-year doctor’s degree that adds 3 years onto the BDS program (Doctor of Dental Surgery, DDS). Typically the 4-year dental school curriculum in North America consists of basic science and preclinical instruction for 2 years plus
262
Dental Abstracts