24 Questions
What is the speed range of conventional low speed hand piece for using Gates-Glidden (GG) burs?
20,000-40,000 rpm
What is the purpose of Gates-Glidden (GG) burs?
Widening the orifices & flaring of the coronal & mid 2/3
What is the motion type of engine driven reciprocating instruments?
30 degree reciprocating motion at 1500 rpm
What is the frequency range of vibratory sonic engine driven instruments?
Less than 20 KHz
What are the disadvantages of engine driven instruments mentioned in the text?
All of the above
What property of Nickel Titanium Endodontic Instruments allows them to return to their original shape even if bent?
Super elastic property
What is the composition of Nickel Titanium Endodontic Instruments?
55% Ni & 45% Ti
What is the purpose of Peeso Reamers?
Post space preparation
What is the corresponding ISO size range for Peeso Reamers?
1-6
What is the speed range of engine driven reciprocating instruments?
1500 rpm
What is the frequency range of Ultra Sonic engine driven instruments?
20-50 KHz
What type of irrigation does Ultra Sonic engine driven instruments use?
Electric- NaOCL irrigant
What are the mode of failures of NiTi instruments?
Torsional and fatigue failures
What are the advantages of Rotary NiTi instruments?
Effortless use, quick canal enlargement, easy debris removal
What are the disadvantages of Rotary NiTi instruments?
Lack of tactile sensation, limited usage, easy fracture
What are the different designs of NiTi rotary instruments based on?
Engineering criteria such as helical angle, pitch, clearance space, rake angle, and radial land
What are the strategies to improve clinical performance of NiTi instruments?
Changing design, surface treatment, manufacturing procedure, thermo-mechanical treatment
What can changing the design of NiTi instruments involve?
Multiple changing tapers, convex triangular cross-section, progressively changing helical angle and pitch
What are the surface treatment techniques for NiTi instruments?
Electropolishing and ion implantation
What does the flute of the file do?
Collects soft tissue and dentine chips removed from the canal wall
What are the different kinematics for NiTi instruments?
Reciprocation and the self-adjusting file (SAF)
What can the instrument tip design be?
Round or batt tip to guide within the canal without cutting
How are rotary NiTi files manufactured?
By machine grinding except for twisted files
What can austenitic and martensitic crystalline structures revert to when stress is released?
The austenitic phase
Study Notes
Improving NiTi Rotary Instruments for Root Canal Enlargement
- Austenitic and martensitic crystalline structures can revert to the austenitic phase when stress is released
- Rotary NiTi files are manufactured by machine grinding except for twisted files
- Advantages of Rotary NiTi include effortless use, quick canal enlargement, easy debris removal, uniform and smooth canals, and time and instrument efficiency
- Disadvantages of Rotary NiTi include lack of tactile sensation, limited usage, easy fracture, and higher cost than stainless steel instruments
- Different designs of NiTi rotary instruments for canal preparation are based on engineering criteria such as helical angle, pitch, clearance space, rake angle, and radial land
- The flute of the file collects soft tissue and dentine chips removed from the canal wall
- Mode of failure of NiTi instruments includes torsional and fatigue failures
- Strategies to improve clinical performance of NiTi instruments involve changing design, surface treatment, manufacturing procedure, thermo-mechanical treatment, different kinematics, and single file systems
- Changing the design of NiTi instruments can involve multiple changing tapers, convex triangular cross-section, and progressively changing helical angle and pitch
- Instrument tip design can be round or batt tip to guide within the canal without cutting
- Surface treatment techniques include electropolishing and ion implantation
- Different kinematics for NiTi instruments include reciprocation and the self-adjusting file (SAF)
Test your knowledge of improving NiTi rotary instruments for root canal enlargement with this quiz. Explore the advantages, disadvantages, designs, and failure modes of rotary NiTi files, as well as strategies for improving their clinical performance.
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