Trošenje dentalnih svrdala

Vidak, Josip (2016) Trošenje dentalnih svrdala. = Wear of dental burs. Master's thesis (Bologna) , Sveučilište u Zagrebu, Fakultet strojarstva i brodogradnje, UNSPECIFIED. Mentor: Jakovljević, Suzana.

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Abstract (Croatian)

Svrdla su rezni alati koji se u stomatologiji primjenjuju za preparaciju zuba i dentalnih materijala. Brusna se tijela svrdala troše različito i nejednako u ovisnosti o materijalu koji režu (keramici, metalu, kompozitnom materijalu). Cilj ovog rada je bila usporedba trošenja radnog dijela svrdala prevučenih dijamantnom prašinom na 4 najčešće podloge korištene u stomatološkoj protetici. Praktični dio istraživanja (brušenje) je izveden na stomatološkom stolcu na koji je instaliran dentalni kolječnik - zračna turbina s vodenim hlađenjem i brojem okretaja od 350.000 o/min. Rezultantna sila kojom je kolječnik opterećen bila je konstantna i iznosila je 3 N. Ispitivanje se provodilo na način da su svrdla istog proizvođača (Komet Dental, SRNJ) podijeljena u 4 skupine svrdala jednake grubosti (ISO zelena oznaka). Skupine su određene prema vrsti podloge na kojoj se ispitivalo trošenje. Podloge korištene u istraživanju bile su: staklo-keramika SiO2-Al2O3-K2O, cirkonij oksid - ZrO2, legura CoCrMo te polimetilmetakrilat – PMMA. Vrijeme trajanja ispitivanja je bilo u intervalima od po 3 minute, 8 minuta te 12 minuta te su nakon svakog vremenskog intervala svrdla čišćena, vagana te ispitivana na skenirajućem elektronskom mikroskopu (SEM). Trošenje, odnosno gubitak mase radnog dijela svrdla ovisio je o materijalu podloge na kojoj je trošen. Nakon vremenskog intervala od 12 minuta izmjeren je sljedeći utrošak mase radnog dijela svrdala: na podlozi od cirkonij oksida 0,31%, na CoCrMo podlozi 0,19%, na staklo-keramici 0,13% te na podlozi od polimetilmetakrilata 0,08%. Zaključuje se da su se nakon vremenskog intervala od 3,8 i 12 minuta najviše potrošila skupina svrdala trošenih na cirkonij oksidu, a najmanje na polimetilmetakrilatu.

Abstract

Burs are cutting tools that are used in dentistry for the preparation of the tooth. The working part of the bur consists of abrasive particles. The wear of the abrasive part of the burs depends on the dental material they are used on. The purpose of this investigation was to compare the diamond coated dental burs working part wear on four most common substrates used in dental prosthetics. Grinding was performed with the dental air turbine handpiece with water cooling system and a speed of 350,000 rpm. Burs were mounted on a handpiece and loaded with 3 N load. Single type of green coarse-grit diamond burs, by the same manufacturer, was studied. Dental burs were divided in four groups, depending on the type of substrate on which they were ground. Materials used in this investigation were: glass-ceramics SiO2-Al2O3-K2O, zirconium oxide - ZrO2, CoCrMo alloy and polymethylmethacrylate - PMMA. The wear was determined as the amount of dental bur weight lost in three time intervals (3 mins, 8 mins, 12 mins). After each interval burs were cleaned, weighed and analyzed by Scanning Electron Microscope (SEM). Dental bur working area wear depends on the type of substrate material on which it is grinded. After 12 minutes the loss of abrasive diamond surface was measured as follows: 0,31% on zirconium oxide substrate, 0,19% CoCrMo alloy, 0,13% on glass-ceramics and 0,08% on polymethylmethacrylate. Highest dental bur working area weight loss was measured in the group of dental burs that were ground on the ZrO2 substrate, while the lowest dental bur working area weight loss was measured in the group of dental burs that were ground on the polymethylmethacrylate substrate.

Item Type:	Thesis (Master's thesis (Bologna))
Uncontrolled Keywords:	svrdlo; trošenje; stomatologija; tribologija; dijamant; staklo-keramika; PMMA; cirkonij oksid; CoCrMo legura
Keywords (Croatian):	dental bur; wear; dentistry; tribology; diamond; glass-ceramic; PMMA; zirconium oxide; CoCrMo alloy
Subjects:	TECHNICAL SCIENCE > Mechanical Engineering BIOMEDICINE AND HEALTH > Dental medicine
Divisions:	1000 Department of Materials > 1010 Chair of Materials and Tribology
Date Deposited:	01 Dec 2016 11:30
Last Modified:	01 Dec 2018 06:07
URI:	http://repozitorij.fsb.hr/id/eprint/7051

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