1. Department of Dentistry, Ng Teng Fong General Hospital and Faculty of Dentistry, National University Health System, Singapore, Singapore
2. National Dental Research Institute Singapore, National Dental Centre Singapore and Duke-, Singapore Health Services, Singapore, Singapore
3. Department of Prosthodontics, Faculty of Dentistry, Universitas Trisakti, Jakarta, Indonesia
4. Department of Oral Medicine, Faculty of Dentistry, Universitas Trisakti, Jakarta, Indonesia