Hand cutting instruments

hand instument used in conservative

1. Hand instruments Submitted by:- Sujoy Kuley Roll no -89 3 rd yr BDS Submitted to:- Dr. Virinder Goyal (Prof.& H.O.D) Dr. Kanika Gupta (Reader) Dr.Suruchi Juneja (Reader) Dr. Aditi Mathur (Senior Lecturer) Dr. Sohajpreet Singh Randhawa (Senior Lecturer)

2. CONTENTS Introduction Classifications Of Instruments Instrument Nomenclature Instrument Parts Instrument Formula Exploring Instruments Cutting Instruments Restorative Instruments Instrument Grasp Finger Rests References

3. Introduction Definition : It is hand-powered dental instruments. History : The early hand-operated instruments characterized by: Large, heavy handles and inferior metal alloys in the blades. cumbersome, difficult to use, and ineffective in many situations. Metal used for Manufacturing Hand Cutting Instrument Carbon Steel Soft steel : contains <0.5% carbon in Iron Hard steel: contains 0.5- 1.5% carbon In Iron Stainless steel Contains 72-85% iron 15-25% chromium 1-2% carbon

4. Classification of Hand Instrument 1.Classification Given By GV BLACK i.Cutting instruments a. Hand cutting instruments -hatchets -chisels -hoes -excavators b. Rotary instruments - burs -stone -discs ii. Condensing instruments a. pluggers -hand -mechanical iii. Plastic instruments -plastic filling instruments -cement cariers - carvers - burnishers - spatulas

5. iv. Finishing and polishing instruments a. Hand -Orangewood sticks -Polishing points -Finishing strips b. Rotary -Finishing burs -Mounted brushes -Mounted stones -Rubber cups v. Isolation instruments -Rubber dam -Saliva ejector -Cotton roll holder -Evacuating tips and equipment vi. Miscellaneous instruments -mouth mirrors -explorers -probes -scissors -pliers -others

6. 2. Classification Given by MARZOUCK i . Exploring instruments - tweezers - Retractors - Probes /Explorers - Separators ii. Instruments for tooth structure removal a. hand cutting -excavators - chisels -special form of chisel b. handpiece -burs - ultrasonic iii. Restoring Instruments -Mixing instruments -Plastic instruments -Condensing instruments -Burnishing instruments -Carvers -Files -knives iv. Finishing and polishing instruments

7. Nomenclature of The Instrument -Given by Dr. GV Black ,to describe instruments for easier identification. i.Order – function or purpose of the instrument. eg . Excavator, condenser ii. Suborder – position, mode or manner of use eg : push, pull iii. Class- design or form of working end eg . Hatchet, spoon excavator iv. Subclass- shape of the shank eg . Binangle , contra-angle

8. Parts of Hand Instrument Handle/ shaft Shank Blade/ Nib Parts of Hand Instrument

9. Handle or Shaft Handle is used to hold the instrument. The handle can be small medium or large , smooth or serrated for better grasping and developing pressure. Different Designs For Instrument Handle For Better Grasping

10. Shank Shank connects the handle to the blade. Shank may be straight or angled. Based on no. of shank angles instrument can be classified as: Straight Monoangle Binangle Tripleangle Quadrangle Contra-angle Instruments With Different Shank Angle

11. Blade / Nib The blade is the last section of instrument. It is the working part of the instrument. For non-cutting instruments, the working part is termed the Nib and is use to place ,adapt and condense the material in the prepared tooth. Blade Nib

12. Instrument Formula GV Black established an instrument formula for describing dimensions of blade, nib or head of the instrument and angle present in shank of the instrument. Two types of formula is used. Three-Number-Formula Four-Number-Formula Instrument Formula

13. Three-Number Formula Used for the instruments in which cutting edges is at right angle to long axis of the blade. 1 st no. -Indicates width of the blade in tenth of millimeter. 2 nd no .- represents the length of blade in millimeter. 3 rd no .- represents the angle which the blade forms with the long axis of the handle in clockwise centigrade. eg .- Enamel hatchet , Hoe, Chisel etc. Schematic Representation Of Three Number Formula

14. Four-Number Formula Used for the instruments in which primary cutting edges is not at right angle to long axis of the blade. 1 st no. -Indicates width of the blade in tenth of millimeter. 2 nd no .-represents the angle formed by the primary cutting edge and long axis of the instrument handle in clockwise centigrade. 3 rd no .- represents the length of blade in millimeter. 4 th no .- represents the angle which the blade forms with the long axis of the handle in clockwise centigrade. e.g. GMT, Angle Former Schematic Representation Of Four Number Formula

15. Exploring instruments Mouth mirror- Used as supplement to improve access to instrumentation. Uses - Direct vision Indirect vision Retraction Trans-illumination

16. Explorer Working tip of explorer is Pointed. Types- Straight explorer- used for occlusal surface. Shephard’s hook/ Curved explorer/ 23 no. explorer - used for examining occlusal surface. Interproximal / Pigtail explorer/ 17 no. explorer- used for examining interproximal surface. Diag. representation of Different types of explorers [A] Interproximal [B] Straight [C] Curved

17. Tweezers/ cotton forceps • Hand instruments with two narrow and pointed, straight or curved beaks to grasp small objects. Uses- in carrying things to and from mouth Carrying cotton rolls, cotton pledges, sponge pellets to and around the cavity

18. Probe They almost look like straight explorer but they have blunt end which marked with graduations Uses- mainly used for measuring pockets To determine dimensions of tooth preparation. Types- Williams Probe Pcp 12 Probe Periodontal Screening & Recording Probe

19. Hand cutting instrument Used to cut hard or soft tissues of the mouth Chisel- Chisels intended primarily for cutting enamel. 1. Straight chisel- • Straight shank and blade with bevel on only one side. • Primary edge perpendicular to the axis of the handle. • Shank and blade of chisel maybe slightly curved 2. Wedelstaedt design or bin-angled Primary cutting edges in a plane perpendicular to the axis of the handle and may have either a distal bevel or mesial bevel (reverse ).

20. Enamel hatchet- • Blade larger, heavier and bevelled on only one side, rather than the ordinary hatchet • Cutting edge in a plane parallel with the axis of the handle • Used for cutting enamel and comes as right or left types for use on opposite sides of the preparation.

21. EXCAVATORS- Ordinary hatchet excavator- cutting edge of blade directed in the same plane as that of the long axis of the handle and is bibevelled . Used -primarily on anterior teeth for preparing retentive areas and sharpening internal line angles, particularly in preparations for direct gold restorations.

22. Hoe Excavators Hoe is any instrument where the blade makes more than a 12.5 angle with the plane of instrument. Uses - shape and smoothen the floor and form line angles in class III & V restorations. Spoon Excavator : It is a modified hatchet. Uses – remove caries and debris in the scooping Motion from carious teeth.

23. Gingival Marginal Trimmer- To produce proper bevel on gingival enamel margins of proximo-occlusal preparations. • Blade curved and primary cutting edge is at an angle • Right and left types- can be mesial or distal pairs • Second number in the formula- • 90-100- pair used on the distal gingival margin • 85-75- pair used to bevel the mesial margin • 100 & 75 pairs- for inlay/ onlay preparations with steep gingival bevels • 90 & 85 pairs- for amalgam preparations with gingival enamel bevels that decline gingivally only slightly Used- for rounding or bevelling of the axio-pulpal line angle of two surface preparations.

24. Restorative Instrument Mixing instrument- Cement spatula Agate spatula Flat and wide nib with blunt edges , straight shank Made of plastic and stainless steel Double ended instrument Blunt end- for manipulation of the impression material Sharp end – for mixing cements Uses - for manual mixing of cements supplied as powder and liquid.

25. Plastic Filling Instrument- Double ended instrument . Used- To mix carry and place the cement. Also used to check the convenience form of tooth preparation. Amalgam Carrier The freshly prepare amalgam restorative material to the prepared tooth Having hollow working ends i.e. Barrels , into which amalgam is packed for transportation .

26. Condenser- The hammer like working end of condenser should be large enough to pack the restoration without sinking into it. Available in differently shaped and sized working ends like Round, Parallelogram or triangular which may be smooth or serrated. Condenser can be hand or mechanical in nature. Use - to deliver restorations to the tooth preparation and properly condense it.

27. Burnisher The kind of instruments which make the surface shiny by rubbing Burnisher have smooth rounded working end. Uses- final condensation of amalgam Initial shaping of occlusion anatomy of amalgam. Smoothen and polish the restoration and to remove scratches present on Amalgam surface after its carving.

28. Carvers- Sharp cutting edges present in carver . Different shape and size in double ended designs. Types- Hollenback carver/ Wards C carver – uses to carve amalgam and inlay wax pattern. Diamond carver/ frahm’s carver- has bibeveled cutting edge. Interproximal carver- it has very thin blade and used for carving proximal surface. Discoid carver- is used for carving occlusal sarface .

29. Instrument Grasp Modified Pen Grasp Inverted Pen Grasp Palm And Thumb Grasp Modified Palm And Thumb Grasp

30. Finger Rests Intra Oral Finger Rest Conventional Finger Rest Cross Arch Finger Rest Opposite Arch Finger Rest Finger On Finger Rest

31. Extra Oral Finger Rest Palm Up Finger Rest Palm Down Finger Rest

32. References 3 rd edition of Textbook of Operative Dentistry by Nisha Garg & Amit Garg . Sturdevant’s Art and Science of Operative Dentistry