1Department of Oral Sciences, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
2Department of Oral Rehabilitation, Faculty of Dentistry, University of Otago, Dunedin, New Zealand
3Department of Preventive and Social Medicine, Dunedin School of Medicine, University of Otago, Dunedin, New Zealand
4Institute for Environmental Science and Research, Christchurch, New Zealand