Malfunction of dental high speed turbine handpiece and cause analysis: a retrospective study for 7 years

Abstract

Objective To analyze the causes of malfunction of high speed turbine handpiece abbreviated as turbine handpiece and put forward preventive measure to guarantee the clinical work and increase service life so as to provide a basis for clinical cost estimation. Methods We retrospected the maintenance records of 85 turbine handpieces in the Fourth Outpatient Department of Peking University Hospital of Stomatology for 7 years, from February 2012 to January 2019 to build the malfunction classification system. The causes were divided into 6 categories based on fault source including the bearing problems (abnormal speed, abnormal voice, poor motivation and bur did not turn) , clip shaft problems (non-jammed bur, the bur could not be taken down and installed) , tightness problems (turbine handpiece leaked water) , fibre-optical problems (the light in the head of turbine handpiece did not work) , waterway problems (the head of turbine handpiece discontinuously sent out water, did not send out water, and the water could not reach the bur) and components loosing (the back cover ejected) . We counted the frequency of all categories of malfunction and analyzed the regularity and causes. Results Among 85 turbine handpieces, there were 142 malfunctions within 7 years. The most frequent problems were the bearing problems (48.59%, 69/142) followed by clip shaft problems (18.31%, 26/142) and tightness problems (16.20%, 23/142) . The bearings were changed for 9 times because of bearing problems showing that the bur did not turn, 2 times in the second, third and four year, 3 times in the fifth year; besides, the bearings could work after being maintained for 60 times. Within 7 years, the frequency of malfunction increased unsteadily and the biggest rise (50 times) was in the seven year. The bearing problems and clip shaft problems began to happen from initial application and the incidences of them were high. The waterway problems, components loosing and tightness problems happened or increased in the fourth and fifth year after application. Conclusions Normal or abnormal component abrasions of turbine handpiece are the root causes of all categories of malfunction. Malfunctions of most components occur from 3 to 5 years after application, and them are close to life time in the seventh year. If the turbine handpiece could not be used or maintained improperly, bearing and clip shaft malfunctions will occur in the early stage. The malfunction classifications of new turbine handpiece contribute to clear the fault source, follow-up maintenance and take the corresponding preventive measures. Key words: Dental instruments; High speed turbine handpiece; Malfunction; Maintain; Lumen instruments