Australian Dental Journal, August, 1978 provided by the public sector is a matter of some concern to many Australians. 2. Letter from Dr Nugent We are familiar with the findings of the “Survey of Dental Practitioners in South Australian Country Areas” which was quoted in Dr Nugent’s letter. In fact, one of the authors is a Council member of the Australian Dental Association South Australian Branch, and was a member of the committee which produced the report “Aspects of Dental Care for the Community” in October, 1976. While the survey provided valuable information for the South Australian Branch, we consider that it is an inadequate document upon which to base the conclusions drawn by Dr Nugent. The figures quoted by him were an estimate, by 40 country practitioners, of the average cost of treating “regular” patients in 1975 and not necessarily an estimate of the annual cost of dental care or the cost of providing care on the basis of need rather than demand. An examination of the quoted figures should convince all but the most sceptical members of the profession that the costs are unrealistically low. On the basis of an hourly rate of $35.25 as at February, 1975, we cannot seriously accept that the entire annual preventive, educative and restorative dental requirements per child for all South Australian children could be provided in 27
365
minutes for the 0.5 age group, and in 41 minutes for the 6-12 age group. In 1975, the School Dental Service provided an average of 2.25 restorations per country child (new and recall patients), in addition to examinations, fluoride applications, extractions, radiographs, endodontics, mouth guards, minor orthodontic appliance therapy and dental health education. In conclusion, Dr Nugent’s concern that “as the school dental programme is extended to cover more patients, the cost per patient is rising sharply” is not borne out by the facts. Using his own figures, the operational cost per patient of the School Dental Service in 1974-75 was $36.05 and, in 1975-76, was $36.91. In real terms there has been a decrease in the cost per child. Has Dr Nugent ever heard of inflation? The increase in capital costs reflect the rapid expansion in the number of clinics and would normally be amortized over 10 or 15 years in accounting terms but is written off at the time of acquisition with economic evaluation. DAVIDBLAIKIE, ROBERTWEIDENHOFER. Dental Health Branch, Department of Public Health, South Australia, 22-30 Bells Road, Somerton Park, S.A., 5044. June 26, 1978.
ORTHODONTICS A N D PREVENTION
Sir, I wish to comment on your Editorial on prevention in relation to orthodontic treatment (Australian Dental Journal, December 1977). Whilst Zachrisson and others have been suggesting for some time fluoride applications prior to banding, the prophylaxis before fitting or cementing may significantly remove much of the superficial fluoride. The obvious solution would be t o apply fluoride in a volatile solvent which would coat and dry the tooth preparatory to cementation, but despite efforts to stir up the dental chemical manufacturers, such a solution has not been forthcoming (such a solution could also have advantages in coating a cavity with fluoride prior to placing amalgam). Therefore, the next logical and practical step is t o include fluoride in the cement (or luting agent). Sodium fluoride completely ruins the zinc and psuedo-copper phosphates cements, which still reign supreme for retention plus lasting properties. Calcium fluoride, at about 10 per cent by volume, add.ed to these cements yields a most acceptable clinical mix and set but the calcium form probably is too bound t o be of much benefit for prevention. Therefore, one is left with the silico-phosphates which leach out suitable quantities of fluoride, and it has been suggested that this can probably be replaced by subsequent topical fluoride applications.
After more than four years of continuous use, I can highly recommend silico-phosphates, but I have not observed the effects of a phenomenon reported by British workers, who indicated that fluoride ions can move from silicate restorations for several millimetres under plaque, to aid remineralization-certainly not in long established decalcified areas. But these do not respond to C.S.P. (calcium sucrose phosphates) either, as compared to recent decalcification which one sees on those younger patients who are restricted from drinking milk by allergists - a practice which is becoming frighteningly common. Despite the fact that saliva is supposed to be super-saturated with calcium ions, most studies have probably been done on dental students, because there is a very small percentage of patients, who have not been drinking milk, and whose decalcified areas respond to milk “swish and swallow” procedures. As all conscientious clinicians would have observed, generalized decalcification is usually due to refined carbohydrates in a liquid form (soft drinks) as compared to the heavily restored posterior teeth associated with solid and semi-solid mediums (e.g., biscuits). This differentiation makes the search for the dietary offender a rather quick matter during the consultation. Having found it, most parents are only too happy to co-operate in reducing the carbohydrate intake and, in fact,
366
Australian Dental Journal, August, 1978
usually ask one to speak to the child. Maybe the dental profession should support recent trends of law-carbohydrate dieting (e.g., “Dr Aiken’s Diet Revolution”). It is my experience that if an orthodontist consistently insists on a low caries experience before undertaking mechanotherapy, he does not lose many friends either within the profession or the community because it can be strongly painted out, by an analogy, that it is more economic in time and money to get the mouth healthy beforehand. Still on the subject of cements, it is strange that those with stannous fluoride have not gained wider acceptance. Possibly this is due to the facts that tests on one of the earlier products indicated it did not have top physical qualities and that clinicians are wary of the staining properties. Logically, the European trend t o re-introduce heavy metals such as copper into cements for their apparent bacteriostatic effects is worthwhile following in view of the unfortunate experience with the bland carboxylates. As you suggest, sodium fluoride can be added to chlorhexidine, and up to two per cent without a deterioration of taste. However, even small concentrations of acidulated fluoride render it unacceptable for oral use. Chlorhexidine administered by toothbrush each visit (i.e., once per month) has not produced a sensitivity case in more than five years of use in my practice, nor has staining been
a problem at this frequency. It would be interesting
to know if the fluoride and chlorhexidine act synergistically on the bacterial population of the plaque. Certainly, the gingivae looks excellent two or three days after a chlorhexidine-fluoride toothbrushing. However, despite these clinical aids, the rash of home-application products coming on the market, and the most conscientious selection of patients for mechanotherapy, there are always a few who lose interest within treatment (which means less co-operation and increased treatment time) and cease maintaining good oral hygiene (which is said to hasten the breakdown of cements); such that the orthodontist has a perplexing problem as to whether to cease or continue treatment. “Nothing succeeds like success” and, for the sake of one’s reputation orthodontically, the decision is often made to press on since previous experience has shown that interest can be rekindled. Nevertheless, in most of these cases, the ravages are more gingival than caries with the use of fluorides mentioned earlier, and even this gingival condition improves immensely following removal of appliances.
B. MQLLENHAUER. 299 Upper Heidelberg Road, Ivanhoe. Vic.. 3079. June 7, ‘1978.-
UNERUPTED THIRD MOLARS
Sir, May I use your columns to air an old controversy? In general practice one is constantly faced with the problem of treatment planning for young teenagers who have all their permanent teeth erupted except the third molars, but with mild to moderate crowding already present. Many of these young patients decline active orthodontic treatment. So the problem then becomes - is it helpful to extract their unerupted eights? In the past, I have confidently recommended such extractions (or removal of lower eights and upper sevens, where radiographs show the unerupted eight should eventually erupt into the vacated seven position). My advice has been on the lines that this won’t make the crowding any better but it should prevent it getting worse. Over the years, I have certainly gained the impression that the patients who have had these extractions done mostly suffer no further anterior crowding; whilst similar patients, who do not have
them carried out, become more crowded. Young patients themselves sometimes tell me that their anterior teeth became crowded as their wisdom teeth erupted. Some even claim they feel pressure symptoms in their lower incisors as their eights erupt. So I have been led to the belief that eruption of third molars can cause anterior crowding - or at least can exacerbate the crowding already present. Yet I am assured by many colleagues that this is not so. I understand the scientific studies reveal no relationship between imbricated lower incisors and the presence or absence of lower third molars. It is a “myth”, I am told, that removing unerupted third molars in young teenagers can prevent imbrication of their incisors. So I write in the hope of sparking discussion of this perennial problem and thereby gleaning more information. DAVIDR. HANNAH. 452 Riverton Drive East, Riverton, W.A., 6155. June 8, 1978.
365
minutes for the 0.5 age group, and in 41 minutes for the 6-12 age group. In 1975, the School Dental Service provided an average of 2.25 restorations per country child (new and recall patients), in addition to examinations, fluoride applications, extractions, radiographs, endodontics, mouth guards, minor orthodontic appliance therapy and dental health education. In conclusion, Dr Nugent’s concern that “as the school dental programme is extended to cover more patients, the cost per patient is rising sharply” is not borne out by the facts. Using his own figures, the operational cost per patient of the School Dental Service in 1974-75 was $36.05 and, in 1975-76, was $36.91. In real terms there has been a decrease in the cost per child. Has Dr Nugent ever heard of inflation? The increase in capital costs reflect the rapid expansion in the number of clinics and would normally be amortized over 10 or 15 years in accounting terms but is written off at the time of acquisition with economic evaluation. DAVIDBLAIKIE, ROBERTWEIDENHOFER. Dental Health Branch, Department of Public Health, South Australia, 22-30 Bells Road, Somerton Park, S.A., 5044. June 26, 1978.
ORTHODONTICS A N D PREVENTION
Sir, I wish to comment on your Editorial on prevention in relation to orthodontic treatment (Australian Dental Journal, December 1977). Whilst Zachrisson and others have been suggesting for some time fluoride applications prior to banding, the prophylaxis before fitting or cementing may significantly remove much of the superficial fluoride. The obvious solution would be t o apply fluoride in a volatile solvent which would coat and dry the tooth preparatory to cementation, but despite efforts to stir up the dental chemical manufacturers, such a solution has not been forthcoming (such a solution could also have advantages in coating a cavity with fluoride prior to placing amalgam). Therefore, the next logical and practical step is t o include fluoride in the cement (or luting agent). Sodium fluoride completely ruins the zinc and psuedo-copper phosphates cements, which still reign supreme for retention plus lasting properties. Calcium fluoride, at about 10 per cent by volume, add.ed to these cements yields a most acceptable clinical mix and set but the calcium form probably is too bound t o be of much benefit for prevention. Therefore, one is left with the silico-phosphates which leach out suitable quantities of fluoride, and it has been suggested that this can probably be replaced by subsequent topical fluoride applications.
After more than four years of continuous use, I can highly recommend silico-phosphates, but I have not observed the effects of a phenomenon reported by British workers, who indicated that fluoride ions can move from silicate restorations for several millimetres under plaque, to aid remineralization-certainly not in long established decalcified areas. But these do not respond to C.S.P. (calcium sucrose phosphates) either, as compared to recent decalcification which one sees on those younger patients who are restricted from drinking milk by allergists - a practice which is becoming frighteningly common. Despite the fact that saliva is supposed to be super-saturated with calcium ions, most studies have probably been done on dental students, because there is a very small percentage of patients, who have not been drinking milk, and whose decalcified areas respond to milk “swish and swallow” procedures. As all conscientious clinicians would have observed, generalized decalcification is usually due to refined carbohydrates in a liquid form (soft drinks) as compared to the heavily restored posterior teeth associated with solid and semi-solid mediums (e.g., biscuits). This differentiation makes the search for the dietary offender a rather quick matter during the consultation. Having found it, most parents are only too happy to co-operate in reducing the carbohydrate intake and, in fact,
366
Australian Dental Journal, August, 1978
usually ask one to speak to the child. Maybe the dental profession should support recent trends of law-carbohydrate dieting (e.g., “Dr Aiken’s Diet Revolution”). It is my experience that if an orthodontist consistently insists on a low caries experience before undertaking mechanotherapy, he does not lose many friends either within the profession or the community because it can be strongly painted out, by an analogy, that it is more economic in time and money to get the mouth healthy beforehand. Still on the subject of cements, it is strange that those with stannous fluoride have not gained wider acceptance. Possibly this is due to the facts that tests on one of the earlier products indicated it did not have top physical qualities and that clinicians are wary of the staining properties. Logically, the European trend t o re-introduce heavy metals such as copper into cements for their apparent bacteriostatic effects is worthwhile following in view of the unfortunate experience with the bland carboxylates. As you suggest, sodium fluoride can be added to chlorhexidine, and up to two per cent without a deterioration of taste. However, even small concentrations of acidulated fluoride render it unacceptable for oral use. Chlorhexidine administered by toothbrush each visit (i.e., once per month) has not produced a sensitivity case in more than five years of use in my practice, nor has staining been
a problem at this frequency. It would be interesting
to know if the fluoride and chlorhexidine act synergistically on the bacterial population of the plaque. Certainly, the gingivae looks excellent two or three days after a chlorhexidine-fluoride toothbrushing. However, despite these clinical aids, the rash of home-application products coming on the market, and the most conscientious selection of patients for mechanotherapy, there are always a few who lose interest within treatment (which means less co-operation and increased treatment time) and cease maintaining good oral hygiene (which is said to hasten the breakdown of cements); such that the orthodontist has a perplexing problem as to whether to cease or continue treatment. “Nothing succeeds like success” and, for the sake of one’s reputation orthodontically, the decision is often made to press on since previous experience has shown that interest can be rekindled. Nevertheless, in most of these cases, the ravages are more gingival than caries with the use of fluorides mentioned earlier, and even this gingival condition improves immensely following removal of appliances.
B. MQLLENHAUER. 299 Upper Heidelberg Road, Ivanhoe. Vic.. 3079. June 7, ‘1978.-
UNERUPTED THIRD MOLARS
Sir, May I use your columns to air an old controversy? In general practice one is constantly faced with the problem of treatment planning for young teenagers who have all their permanent teeth erupted except the third molars, but with mild to moderate crowding already present. Many of these young patients decline active orthodontic treatment. So the problem then becomes - is it helpful to extract their unerupted eights? In the past, I have confidently recommended such extractions (or removal of lower eights and upper sevens, where radiographs show the unerupted eight should eventually erupt into the vacated seven position). My advice has been on the lines that this won’t make the crowding any better but it should prevent it getting worse. Over the years, I have certainly gained the impression that the patients who have had these extractions done mostly suffer no further anterior crowding; whilst similar patients, who do not have
them carried out, become more crowded. Young patients themselves sometimes tell me that their anterior teeth became crowded as their wisdom teeth erupted. Some even claim they feel pressure symptoms in their lower incisors as their eights erupt. So I have been led to the belief that eruption of third molars can cause anterior crowding - or at least can exacerbate the crowding already present. Yet I am assured by many colleagues that this is not so. I understand the scientific studies reveal no relationship between imbricated lower incisors and the presence or absence of lower third molars. It is a “myth”, I am told, that removing unerupted third molars in young teenagers can prevent imbrication of their incisors. So I write in the hope of sparking discussion of this perennial problem and thereby gleaning more information. DAVIDR. HANNAH. 452 Riverton Drive East, Riverton, W.A., 6155. June 8, 1978.
