title: Dental ablation with 1064 nm, 500 ps, Diode pumped solid state laser: A preliminary study.
abstract: BACKGROUND
  The Er:YAG laser in conservative dentistry is. good alternative to conventional instruments. Though several studies show the advantages of these devices, some drawbacks and unsolved problems are still present, such as the cost of the device and the large dimensions of the equipment.
  
  
  OBJECTIVE
  In the present study, the effectiveness of dental surface ablation with a picosecond infrared diode-pumped solid-state (DPSS) laser was investigated. In vitro tests on extracted human teeth were carried out, with assessment of the ablation quality in the tooth and thermal increase inside the pulp chamber.
  
  
  METHODS
  A solid-state picosecond laser was used for the experiments. The samples were exposed to laser energy at 1064 nm at a frequency of 30 kHz and a 500 ps pulse width. The target teeth were cooled during exposures. The internal temperature of the pulp chamber was monitored with. thermocouple.
  
  
  RESULTS
  Optical microscope images showed effective ablation with the absence of carbonisation and micro-cracks. The cooling maintained the temperature rise in the pulp chamber below the permitted 5.5°C.
  
  
  CONCLUSIONS
  The main problem with the use of lasers in dentistry when teeth are the target is the heat generated in the pulp chamber of the target teeth. With lasers operating in the femtosecond mode, a better management of the internal temperature is possible, but is offset by the high cost of such devices. With the ps domain system used in the present study together with cooling using chilled water, effective and clean ablation could be achieved with a controlled thermal effect in the pulp chamber.
  
  
  CONCLUSIONS
  In this preliminary study with a picosecond domain DPSS laser using water cooling for the target, effective hard tissue ablation was achieved keeping the thermal increase in the pulp within the permitted range. The results suggest that this system could be used in clinical practice with appropriate modifications.
authors.affiliation: Department of Information Engineering and.
authors.forename: Michele
authors.initials: M
authors.lastname: Sozzi
authors.forename: Carlo
authors.initials: C
authors.lastname: Fornaini
authors.forename: Annamaria
authors.initials: A
authors.lastname: Cucinotta
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Merigo
authors.forename: Paolo
authors.initials: P
authors.lastname: Vescovi
authors.forename: Stefano
authors.initials: S
authors.lastname: Selleri
keywords: enamel; laser ablation; laser dentistry; pulp chamber