The ball mill as a means of investigating the mechanical failure of dental materials.
OBJECTIVE
The main purpose of this paper is to present a new method of predicting clinical performance using mechanical loading in a ball mill.


METHODS
A series of four experiments (two involving a hybrid composite and one each on orthodontic brackets and bands) is described in which the ball mill was used to subject specimens to mechanical fatigue.


RESULTS
A reproducibility study using composite beam specimens showed no significant difference between the Mean Survival Time (MST) in all the three experimental runs (P = 0.42). When subjected to thermal cycling, the MST of the cycled group was 155.0 min compared to 247.0 min for the control group (P < 0.01). The MST of untreated and sandblasted brackets was 7.9 h and 14 h respectively (P < 0.01). There is also a significant difference (P < 0.001) in the MST of sandblasted bands when compared to the untreated bands.


CONCLUSIONS
The ball mill proved to be a convenient and reproducible means of producing mechanical fatigue and may be useful in predicting the clinical performance of dental materials.
Abu Kasim
N H
NH
Dental Materials Science Unit, Dental School, Newcastle upon Tyne, UK.
Millett
D T
DT
McCabe
J F
JF
D017438:Bisphenol A-Glycidyl Methacrylate / Q000737:chemistry; D003188:Composite Resins / Q000737:chemistry; D003764:Dental Materials / Q000737:chemistry*; D017220:Dentin-Bonding Agents / Q000737:chemistry; D004867:Equipment Design; D005544:Forecasting; D005899:Glass Ionomer Cements / Q000737:chemistry; D008277:Magnesium Oxide / Q000737:chemistry; D008422:Materials Testing / Q000295:instrumentation*; D009967:Orthodontic Appliances; D016910:Orthodontic Brackets; D011076:Polycarboxylate Cement / Q000737:chemistry; D015203:Reproducibility of Results; D019279:Resin Cements; D012399:Rotation; D013193:Stainless Steel / Q000737:chemistry; D013314:Stress, Mechanical; D013499:Surface Properties; D013696:Temperature; D015034:Zinc Oxide / Q000737:chemistry
D003188:Composite Resins; D003764:Dental Materials; D017220:Dentin-Bonding Agents; D005899:Glass Ionomer Cements; D011076:Polycarboxylate Cement; D019279:Resin Cements; C065771:P50 composite resin; C071164:Right-On cement; D013193:Stainless Steel; D008277:Magnesium Oxide; D017438:Bisphenol A-Glycidyl Methacrylate; C040235:Ketac-cem; D015034:Zinc Oxide