Table 2.

Restoration failure and their relationship with dentists’ and tooth’s characteristics

VARIABLE	Restorations in study % (n) n=5,889	Restorations that failed % (n) n = 378
Practice Model
SP	74% (4,358)	5% (213)
LGP	22% (1,283)	12% (148)
PHS	4% (248)	7% (17)
Decade of dental school graduation
- 1979	29% (1,680)	6% (76)
- 1980–1989	45% (2,630)	6% (156)
- 1990–1999	13% (761)	7% (53)
- 2000–2008	14% (818)	8% (68)
Treatment
Repaired	25% (1,498)	7% (144)
Replaced	75% (4,391)	5% (234)
Tooth
Molar	54% (3,148)	7% (228)
Upper	25% (1,483)	8% (118)
Lower	28% (1,665)	7% (110)
Pre Molar	26% (1,515)	5% (81)
Upper	14% (816)	5% (37)
Lower	12% (699)	6% (44)
Anterior	21% (1,226)	6% (69)
Upper	16% (938)	5% (42)
Lower	5% (288)	9% (27)
Number of surfaces in repair/replacement
One	27% (1,589)	6% (87)
Two	32% (1,869)	7% (114)
Three	22% (1,294)	7% (81)
Four	9% (512)	9% (48)
Five	11% (625)	6% (48)
Material of the original restoration
Amalgam	53% (3,054)	6% (194)
Direct tooth-colored	37% (2,154)	6% (135)
Indirect tooth-colored	11% (606)	7% (43)
Missing information (n=81)
Repair/replacement material
Amalgam	21% (1,215)	10% (117)
Direct tooth-colored	58% (3,338)	6% (182)
Indirect tooth-colored	22% (1,252)	6% (71)
Missing information (n=92)
Reason for repair or replacement
Secondary/recurrent caries	43% (2,514)	7% (167)
Fracture/bulk fracture/missing	36% (2,095)	8% (157)
Degraded/ditched	8% (461)	4% (16)
Other	7% (399)	4% (16)
Margins or restoration discolored	3% (196)	3% (6)
Patient request	2% (127)	5% (6)
Pain sensitivity	1% (65)	9% (6)
Missing information (n=36)

SP = solo or small group practices

LGP = large group practices

PHS = public health care settings