Report of a Consultancy Project undertaken on behalf of the Department of Health & Children and the Regional Health Boards by the Oral Health Services Research Centre, University College Cork, Ireland 1 Table of Contents User Group 5 OHSRC Project Team 6 Summary 7 Chapter 1 – The Consultancy Research Programme 1.0 Introduction 10 1.1 Water Fluoridation 11 1.2 Fluoride Mouthrinsing 11 1.3 Fluoride Toothpaste 12 1.4 Other forms of systemic fluoride supplementation 12 1.5 Combinations of the above including matters relating to intake 13 1.6 Research Plan 13 Chapter 2 – Fluoride Use in Ireland: A Situation Analysis 2.0 Introduction 16 2.1 Structure 16 2.2 Process and Outcome 19 2.2.1 Situation Analysis Questionnaire 20 2.3 Recommendations 22 Chapter 3 – Fluoride Intake & Absorption 3.0 Introduction 26 3.1 Fluoride Intake 26 3.1.1 Diet 27 3.1.1.1 Development of methods for monitoring the diet of 2 to 3 year old children 27 3.1.1.2 Development of standard fluoride analytical methods 28 3.1.1.3 Fluoride levels in powdered infant formula 28 3.1.1.4 Infant feeding practices 29 3.1.1.5 Fluoride content of beverages 29 3.1.2 Oral health care products 30 3.1.2.1 Mouthrinses 30 3.1.2.2 Toothpastes 30 3.1.2.3 Fluoride containing dental materials 31 3.2 Fluoride Absorption 32 3.2.1 Saliva 32 3.2.2 Plasma 33 3.2.3 Urine 33 3.2.4 Tooth Enamel/Fluorosis 34 3.2.5 Fingernails 34 3.3 Other Related Projects 35 2 Chapter 4 – Fluoride Acculation in Bone 4.0 Introduction 37 4.1 Association between Fluoridation of Water Supplies and the Incidence of Fracture neck of femur 37 4.2 Femoral Bone Fluoride and Risk of Fracture neck of Femur 39 References 40 3 Appendix 1 Situation Analysis 42 Appendix 2 The approach adopted to Lot 2 contract 76 Appendix 3 The evidence base for topical fluorides 90 Appendix 4 Dietary fluoride Intake in 2-3 year old children 96 Appendix 5 Development of standard fluoride analytical methods: pilot study 101 Appendix 6 Fluoride levels in powdered infant formula with fluoridated water 103 Appendix 7 Fluoride intake in infants 105 Appendix 8 The properties of common beverages relevant to dental health 108 Appendix 9 The properties of over-the-counter mouthrinses on Sale in the Republic of Ireland 116 Appendix 10 EU flint project - abstracts of 11 published papers 137 Appendix 11 Fluoride containing restorative materials 146 Appendix 12 A study of the relationship between oral hygiene habits, salivary fluoride levels and dental caries 155 Appendix 13 Dental fluorosis in primary teeth of 5-year-olds in Ireland 159 Appendix 14 Fluoride levels in fingernail clippings from fluoridated and non-fluoridated communities 161 Appendix 15 Fluoride ingestion from tea amongst adults in Ireland 165 4 USER GROUP Dr Joe Mullen, Principal Dental Surgeon, North Western Health Board, Health Centre, Markievicz House, Barrack Street, Sligo. Dr. Leo Burke, Principal Dental Surgeon, South Eastern Health Board, Community Care Area, Athy Road, Kildare Dr. Pat Costello, Principal Dental Surgeon, Western Health Board, Dental Department, Shantalla Clinic, Galway Dr. Stephen McDermott, Principal Dental Surgeon, East Coast Area Health Board, Glenside Road, Wicklow. Dr. John Jones, Principal Dental Surgeon, Southern Health Board, Dental Clinic, Moyderwell, Tralee, Co. Kerry. Dr. Maria Kenny, Principal Dental Surgeon, Mid Western Health Board Health Centre, Arden Road, Tullamore, Co. Offaly. Dr. Joe Greene, Principal Dental Surgeon, Mid Western Health Board, Dental Clinic, Bindon Street, Ennis, Co. Clare. Dr. Fergal Connolly, Principal Dental Surgeon, North Eastern Health Board, Dental Department, Cavan General Hospital, Cavan. Dr. Kay O’Leary, South Eastern Health Board, Community Care Centre, Cork Road, Waterford. 5 OHSRC Project Team Project Manager: Professor Denis O’Mullane Oral Health Services Research Centre University Dental School and Hospital Wilton, Cork Deputy Project Manager: Dr. Helen Whelton, OHSRC Other Members of the Lot 2 Team: Mr. Paul Beirne, Health Research Board Fellow Ms. Elspeth Cameron, OHSRC, University Dental School and Hospital Dr. Kevin Cashman, Department of Food Science, Food Technology and Nutrition, UCC Ms. Niamh Cronin, University Dental School and Hospital Ms. Evelyn Crowley, Research Fellow Dr. David Cocker, Analytical Chemistry, UCC Ms. Cait Fitzgerald, Postgraduate student, Department of Food Science, Food Technology and Nutrition, UCC Professor Albert Flynn, Department of Food Science, Food Technology and Nutrition, UCC Ms. Mairead Harding, Southern Health Board, University Dental School and Hospital Ms. Mairead Kiely, Department of Food Science, Food Technology and Nutrition, UCC Ms. Rose Kingston, Postgraduate student, OHSRC Ms. Jennifer Leyden, OHSRC, University Dental School and Hospital Ms. Eileen MacSweeney, Head Laboratory Technician, OHSRC Ms. Fiona MacSweeney, University Dental School and Hospital Ms. Sinead McDonnell, Registrar in Paediatric Dentistry, UCC Ms. Deirdre Sadlier, Director of the Irish Dental Health Foundation Ms. Maria Tobin, OHSRC, University Dental School and Hospital Undergraduate Students who participated in the HRB Summer Scholarship Summer Schemes: Abdul Hakeem Al Masroori Elizabeth Moloney Patrick O’Beirne 6 SUMMARY Introduction In 1999 the Oral Health Services Research Centre (OHSRC) undertook a consultancy research project on behalf of the Department of Health and Children in collaboration with the Health Boards to investigate the current use of fluorides in the promotion of health and in particular oral health in the Republic of Ireland and to make recommendations on their use in the future. This contract was Lot 2 of a series of ten consultancy contracts in the Oral Health area which were awarded at the time. Background to use of fluoride in Ireland for the control of dental caries Following the enactment of the Health (Fluoridation of Water Supplies) Act 1960 water fluoridation was introduced in Dublin in 1964 and in Cork in 1965. Over the next 10 years or so fluoride was added to the domestic water supplies of the main urban areas in the Republic of Ireland. At present 73% of the population resides in communities served with fluoridated water supplies. During the late 60s and early 70s a number of fluoride tablet programmes were initiated in a number of non fluoridated communities with a view to providing the benefits of systemic fluoride to those children residing in mostly rural communities where fluoridation of water supplies was not feasible. However, with increasing knowledge of the methods of action of fluoride in the control of dental caries and also due to concerns about the appropriate dosage to be used by children of different ages as well as problems with compliance of participants, use of fluoride tablets declined during the 90s and their use has been largely discontinued at this time. In 1969 fluoride toothpastes were first introduced in the Republic of Ireland and over the subsequent 10/15 years they represented an increasing proportion of the toothpaste market in the Republic of Ireland. It is now estimated that over 95% of toothpastes sold over the counter contain fluoride. In 1968 the first fluoride mouthrinsing programme was introduced in the Republic of Ireland and currently approximately 30,000 Primary School children participate in fluoride mouthrinsing programmes Following the discovery of the relationship between fluoride in domestic water supplies and the incidence of dental caries in the 1940s, efforts were made by researchers to develop products which could be applied by dentists and auxiliary dental workers to individual patients in dental clinics. These products, such as gels, varnishes and filling materials, containing high levels of fluoride, were first introduced to Ireland in the mid 1960s. They continue to be used by clinicians in Ireland. Many studies have shown that certain food products contain high levels of fluoride, these include tea and fish. When the decision was taken to introduce water fluoridation in Ireland, the evidence at the time showed that the benefit (i.e. reduction in dental caries) would be accompanied by a slight increase in the questionable and very mild grades of fluorosis. At the time it was considered that this risk of fluorosis was acceptable taking into account the benefit to be derived in the form of a reduction in the incidence of dental caries likely to lead to an overall improvement in oral health. 7 In the late 70s and continuing throughout the 80s however, the dental research community and dental public health workers began to raise concerns about the increased exposure of the population to fluoride from different sources as outlined above. Forum on Water Fluoridation During the course of the work undertaken under Lot 2 the Forum on Water Fluoridation was established by the Minister for Health & Children in September 2001. A number of the aims of Lot 2 overlapped those of the Forum on Water Fluoridation hence, the reader of this report will be frequently referred to the Report of the Forum on Water Fluoridation (www.fluoridationforum.ie) EU Project “Fluoride Ingestion from Toothpaste” FLINT When bidding for the Lot 2 Consultancy contract the Oral Health Services Research Centre (OHSRC) highlighted the fact that it had recently been successful in obtaining funding under the EU BIOMED 2 Research & Technical Programme to investigate methods of measuring fluoride ingestion from toothpaste and of measuring enamel fluorosis. The aims and objectives of this project are very closely linked with those of the Lot 2 consultancy project and also with the aims of the Forum on Water Fluoridation. The reader of this report should be aware of this interlinking of the activities of the OHSRC. In April 2004 the results of the FLINT multicentered project were published in a special supplement of Community Dentistry and Oral Epidemiology. (Ketley, O’Mullane and Holbrook, 32, Supplement 1, 1-76, April 2004).