Table 2.
Descriptive background data. Background data for the treatment group, the reference group and for patients excluded from the treatment group. Data obtained at the initial examination and from Questionnaire 1 (Q1)
| Treatment group (n = 20) | Reference group (n = 20) | Excluded from treatment group (n = 10) | Data from | |
|---|---|---|---|---|
| Women, n (%) | 14 (70) | 16 (80) | 8 (80) | |
| Age (years) in September 2000, mean (s.d.) | 46·9 (6·7) | 44·7 (6·5) | 52·6 (7·0) | |
| Education (years), mean (s.d.) | 11·5 (3·6) | 11·3 (2·8) | 10·3 (2·6) | Initial ex. |
| Reported smoking at initial examination, n (%) | 4 (20) | 7 (35) | 3 (30) | Initial ex. |
| On sick leave or disability pension, n (%) | 9 (45) | 7 (35) | 9 (90) | Q1 |
| Regular dental care, n/valid n† (%) | 17/18 (94) | 20/20 (100) | 6/7 (86) | Q1 |
| Used medication last 12 months, n (%) | ||||
| Analgesics | 13 (65) | 13 (65) | 7 (70) | Q1 |
| Antidepressants | 6 (30) | 3 (15) | 2 (20) | |
| Vitamins/dietary supplements | 13 (65) | 13 (65) | 8 (80) | |
| Participants' assessments of risks associated with dental amalgam, n (%) | ||||
| Very high | 17 (85) | 15 (75) | 10 (100) | Q1 |
| Medium | 3 (15) | 4 (20) | – | |
| Low | – | – | – | |
| Very low | – | – | – | |
| Missing | – | 1 (5) | – | |
| Number of amalgam surfaces, mean (s.d.) | 36·8 (11·1) | 38·0 (11·3) | 27·2 (16·3) | Initial ex. |
| Concentration of mercury, mean (s.d.) | ||||
| Blood (nmol L−1) | 23·5 (10·4) | 27·5 (12·5) | 33·0 (22·1) | Initial ex. |
| Urine (nmol L−1) | 24·0 (17·6) | 22·0 (16·4) | 21·0 (19·7) | |
| Urine (nmol per mmol creatinine) | 2·7 (1·9) | 2·6 (2·7) | 2·4 (2·3) | |
| Self-reported health complaints, mean (s.d.) | ||||
| Intra-oral index | 8·4 (6·6) | 13·0 (12·0) | 11·2 (7·2) | Q1 |
| Extra-oral index | 6·9 (8·4) | 11·0 (9·3) | 9·2 (8·0) | |
| General index | 41·5 (16·0) | 47·3 (21·2) | 42·3 (15·0) | |
†
Five patients did not answer the question but had started removal of amalgam restorations.