CONTACTS AND CONTOURS IN DENTISTRY

INTRODUCTION
ROLE OF CONTACTS AND CONTOUR
HAZARDS
TYPES

1. CONTACTS AND CONTOURS DR. JAMES

2. CONTENTS Introduction Role Of Contacts And Contours Benefits Of Ideal Contacts And Contours Types Of Contacts And Contours Problems Associated With Faulty Reproduction Of Contacts In Restoration Reproduction Of Contacts In Restoration Classification Of Wedges Wooden And Plastic Wedging Techniques Single Wedge Technique Piggy Back Wedging Double Wedge Technique Wedge Wedging Technique Automatrix Hazards Of Improper Contacts And Contours Recent Advances

3. Contact Contact is the term used to denote the “ proximal height of contour of mesial and distal surface of the tooth that touches its adjacent tooth in the same arch.”  Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

4. Contact Point Contact point has been defined as the point when teeth erupt and acquire proximal contact with adjacent tooth proximal attrition leads to the conversion of contact point to contact area. Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

5. All teeth have there contact point c entred f aciolingual (slightly buccal of the middle 3rd).               2nd premolar / 1st molar / 2nd molar contact point have a straight line that bisects every contact point

6. IMPORTANCE OF C ONTACT POINTS Conserves the teeth from interproximal caries It creates a natural embrasure by maintaining good oral hygiene at the interproximal area Preserves the stability and integrity of the arch by maintaining normal mesio -distal relationship of teeth. Prevent food impaction interdentally Protect the soft tissue from periodontal disease

7. C ONTACT POINTS Mesially – contacts the incisal 3 rd of crown Distally – contact occurs slighty higher Distal ouline of central insor are rounded Incisal embrasures are slight Central incisor

8. Lateral incisor Lateral incisor has a shorter crown and more rounded mesioincisal angle Mesial contact area on lateral are above the incisal 3 rd of the tooth. Embrasures approaching distally are larger than mesial to central

9. Canine Mesial contact area of canine are in junction between incisal and middle 3 rd Distal slope of canine are larger Distal contact area is at centre of middle 3 rd of crown. Embrasures are larger than central and lateral incisors

10. 1 st premolars and 2 nd premolars Mesial contact area is cervical to the junction of incisal and middle 3 rd . Embrasure b/w teeth have wide angle. Form of these teeth creates wide occlusal embrasure

11. 2 nd premolars and 1 st molar Contact area is cervical to the junction of incisal and middle 3 rd .

12. 1 st 2 nd and 3 rd molars Contact area appraoches the middle third of the crown.

13. SIZE &LOCATION OF CONTACT POINT AND CONTACT AREAS Location of contact Anterior teeth – Incisal 1/3rd Posterior teeth – Junction of incisal and middle 1/3rd Size of contact Anteriorly, Posteriorly –contact area about 1.5-2mm

14. Contact Areas According to Zeisz and Nuckulls the contact area is a flattened position of tooth, refers to the surface area where the proximal surfaces of neighboring teeth come in contact. Contact area is usually located in upper one third of the crown of most of the tooth The proximal contact area is located in the incisal third of the approximating surfaces of the maxillary and mandibular central incisors, Faciolingually - positioned slightly facial to the center of the proximal surface Proceeding posteriorly from the incisor region , the contact area are located near the junction of the incisal (or occlusal) and middle third . Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

15. Role of Contact Area Allows a good support against masticatory forces Promotes the deflection of the food through the embrasure. Influences speech and cosmetics especially in the anterior region. Improper restoration in the contact area will cause displacement of the teeth lifting forces of the teeth rotation of the teeth deflecting occlusal contact food impaction. Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

16. bucco -lingually or occlusal-gingivally causes improper shunting of food because of narrow embrasure this leads to food impingement in the contact area PROBLEMS ASSOCIATED WITH FAULTY REPRODUCTION OF CONTACTS IN RESTORATION Too B road Contact Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

17. bucco -lingually or occluso -gingivally causes food impaction vertically and horizontally due to wide embrasure in which lead to greater food retention and plaque accumulation Too Narrow Contact Too occlusally, bucally or lingually Contact area placed too occlusally, buccally or lingually will result in flattened marginal ridge of the restoration Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

18. OPEN C ONTACT Causes accumulation of debris , plaque and damage to the periodontal disease leading to food impaction Contact point too gingivally will lead to increased depth of occlusal embrasure leading to food impaction Too gingivally

19. Interdental Col Valley like depression situated apical to contact point /contact area. Connects facial and lingual papillae Pyramidal or col shaped occupying the gingival embrasure. Epithelium of col is thin and non keratinised.

20. Supragingival margins Provides easy preparation of the tooth, finishing of the margins, impression making, fit and finish of the restoration. Verification of the marginal integrity of the restoration is easiest. least irritating to the periodontal tissues Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

21. Subgingival margins If the margin is placed to far below the alveolar crest it impinges on gingival attachment and creates a violation of biologic width. Subgingival margins increased plaque index, gingival recession and increased pocket depth Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

22. Equigingival margins Traditionally this type of margins were not desirable-food accumulation which tends to increased gingival inflammation and minor gingival recession . Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

23. Contours “ Contour denotes some degree of convexities and concavities on the facial/buccal and lingual/palatal surface of all teeth that affords protection to the supporting tissue during mastication.” generally located at the cervical third of the crown on the facial and lingual surfaces of the incisors and canines. The lingual surfaces of the posterior teeth usually have their height of contour in the middle third of the crown. Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

24. Role of contact : Allows “ normal healthy interdental papilla to fill the interproximal spaces.” “Stabilizes and maintains the integrity of dental arches.” It prevents the food from getting trapped in between the teeth It prevents the impingement to the gingival tissue. Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

25. Role of contour : They are involved in occlusal static and dynamic relation as they determine the pathway for the teeth into and out of centric occlusion. They fullfill the function and form of embrasures. Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

26. On the Facial side : height of contour of all teeth - Cervical 3rd. On the Lingual side : height of Contour are: Anterior Teeth: Cervical 3rd. Posterior Teeth: Middle Third.

27. BENEFITS OF AN IDEAL CONTACT & CONTOUR Conserves the health of peridontium Prevents food impaction Makes area self cleansable Improves longevity of proximal restorations Maintains mesiodistal relationship of the teeth Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2

28. CONTACT TAPERING SQUARE OVOID Betwee n incisors I ncisal ridge - incisally , L abial ly - labiolingual ly Incisal ridge- incisally , Labially - labiolingually Slightly lingual to incisal ridge Canine Mesial -contacts incisal ridge Distal -contacts middle third Close to incisal ridge incisally Labiolingually Close to incisal ridge incisally Bicuspids A lmost at bucco -axial angle T owards bucco -axial angle J unction of buccal & middle third Occlusal - junction of occlusal & middle 3 rd of crown O cc lu s a l p er i p h er y - o c c l us a l third

29. Molars (mesial c o nt ac t) A lmost at bucco -axial angle of tooth Occlusal - at junction of occlusal & middle third of crown Molars (distal contact) Buccal periphery at middle third More lingually deviated than mesial Buccal periphery - central groove

30. TYPES OF CONTOUR OVERCONTOUR Inadequate stimulation by passage of food Posing greater risks to periodontal health . Both supragingival and subgingival plaque accumulation occurs. UNDERCONTOUR Results in overhanging of restoration and trauma to soft tissue ADEQUATE CONTOUR Stimulation of supporting tissues Healthy peridontium

31. Types of Contact Areas TAPERED TYPE SQUARE TYPE OVOID TYPE

32. In an inciso -apical direction-contact of maxillary central and lateral incisors start incisally near the incisal edges. In a labio-lingual direction -labial to the incisal edges . Tapered cuspid - angular with the mesial contact area close to the incisal edges & distal contact area near the center of the distal surface. As these crowns taper lingually, the contact areas occur buccally at buccal axial angle of the tooth. The bicuspid contact -just gingival from the junction of the occlusal and middle third of the crown. TAPERED TYPE

33. The concavities are more pronounced on mesial than on distal surfaces B ucco-lingually -Mesial contact of molar contacts the mesio -buccal axial angle of the tooth Proximal contour - starts at the CEJ , surface presents a concavity to the contact areas and convexities to the crest of the marginal ridges. Labiolingually - gingival embrasures between anterior teeth are extended incisally and wider at gingival crest . B uccolingually - gingival embrasures between posterior teeth are broad whereas the lingual embrasures are wide

34. 2. SQUARED TYPE This type of tooth is bulky and angular, with little rounded contour. T eeth have relatively short cusps Labiolingually , incisally -The incisor contacts are in a line with the incisal edges, O cclusal contact of the posterior teeth - occlusal one third of the crown. Proximal contours of these type of teeth tend to become a plane instead of curved surface Buccolingual concavities are found on mesial surface of maxillary 1 st and 2 nd molars and maxillary 1 st premolars Distal surface are either flat /slight convex from buccal to lingual surface

35. Transitional type between the tapered and square types. Its surfaces are primarily convex . In an inciso -gingival direction- the mesial contact of the incisors origins from 1/4 th the height of the crown from the incisal edges . The distal contact -1/3 rd to ½ the height of the crown from the incisal edge Proximal contours of ovoid anterior teeth are convex from the incisal angle to the CEJ . The mesial surfaces of ovoid molars present convex areas which are less extensive than those on distal surfaces 3. OVOID TYPE

36. EMBRASURES (SPILLWAYS ) V-shaped spaces between the teeth that originate at the proximal contact areas between adjacent teeth. TYPES – occlusal , gingical and incisal embrasures Serves 2 purposes – Provides a spillway for passage for food during mastication Prevents food from being forced into the contact area

37. This is an immediate type of separation . This type of tooth movement involves separation of teeth proximally at the point of insertion of separator. The amount of separation produced should not exceed 0.2-0.5mm. Rapid separation can be done by two method Wedge method Traction method RAPID SEPARATION

38. WEDGE METHOD OF SEPARATION In this method space is created by inserting wedge shaped device between the teeth. There are two types of separator Wooden / Plastic wedges Elliot separator

39. CLASSIFICATION OF WEDGES On the basis of method of fabrication Custom made wedges Pre - fabricated wedges On the basis of material used for fabrication Wooden wedges Plastic or synthetic resin wedges

40. PRE-FABRICATED WEDGES They are in triangular in shape and supplied in different size. Their shape should modified by trimming to exactly meet that of the gingival embrasure.

41. These are transparent plastic wedges ,which are available - built in light reflecting property. Indication Class II composite restoration : These light transmitting wedges help to assist in directing light into inter proximal areas during initial stages of class II composite curing . LIGHT TRANSMITTING WEDGES

42. Single wedge technique Single wedge is placed in the gingival embrasure Piggyback wedging A second wedge is placed on top of the first wedge to wedge adequately the matrix against the margin Indicated for patients whose interproximal tissue level has receded. WEDGING TECHNIQUES

43. Double wedging technique Here, 2 wedges, one from the facial embrasure and the other from the lingual embrasure are used. Used when proximal box is wide facio - lingually. Wedge wedging technique Used in cases when there is a gingival concavity A second wedge is inserted between the first wedge and the band.

44. Functions of W edges They create space between teeth to compensate the thickness of matrix band. Immobilize the matrix band. Closely press es the matrix band against the tooth in the gingival area of the preparation preventing any restorative material escaping below the band. Maintaining the health of interdental gingiva by preventing material from impinging into the tissues. Protect the gingiva from unexpected tr auma .

45. BIOLOGIC WIDTH Represents combination of epithileal and connective tissue ie.sulcus of 0.69 mm, epithelial attachment of 0.97 mm and a connective tissue width of 1.07 mm coronal to the crest of the alveolar bone It provides the natural seal that develops around the tooth protecting the alveolar bone from the infection and the disease Restoration that impinges upon biologic width would lead to progressive periodontal disease. The margins of restoration should be more than 2mm coronal to alveolar crest.

46. Biologic width may vary from tooth to tooth which increases progressively from anterior to posterior teeth Anterior teeth – 1.75 mm Premolars - 2.97 mm Molars - 2.08 mm

47. Elliot S eparator It is also called crab claw separator. It is mainly used for : Examination of proximal surface Final polishing of already restored proximal surface.

48. Matrix band Applied in procedures where temporary wall is created opposite to axial wall that surrounds the area of the tooth structure Forms a 360 degree contour and a wall replacing the missing wall in cavity preparation. The height of the band should be such that it extend 2mm above the marginal ridge and 1mm below gingival margin of the preparation.

49. CLASSIFICATION OF MATRIX BAND Based on mode of retention: With retainer (Tofflemire matrix) Without retainer (Automatrix) Based on type of band Metallic non transparent Nonmetallic transparent Based on type of cavity Class I cavity - Double banded Tofflemire (barton’s matrix)

50. Class II cavity Single banded Tofflemire Ivory matrix No. 1 Ivory matrix No. 8 Copper band matrix Automatrix Class III cavity Mylar strip S-shaped Class IV cavity Mylar strip Transparent crown matrix Modified S-shaped Class V Cervical matrix Window matrix

51. Ideal r eq u ireme n ts of Matrix It should be simple in design. It should be easily applied and readily removed It should be rigid enough to withstand condensation pressure preventing the restorative material bulging out. It should be able to adapt with the shape and position of different types of tooth. It should be non reactive to the tissue and restorative material. It should be inexpensive and readily available. It should be easy to sterilize.

52. Ivory Matrix No.1 Band encircles the posterior proximal surfaces indicated in unilateral class II cavities. Band is attached to the retainer via a wedge shaped projection. Adjusting screw at the end of the retainer adapts the band to the proximal contour of the prepared tooth.

53. Ivory Matrix No. 8 Consists of band that encircles the entire crown of the tooth. Indicated for bilateral class II cavities. Circumference of the band can be adjusted by adjusting the screw present in the retainer.

54. Roll in band matrix ( Automatrix) Retainerless matrix system with 4 types of bands that are designed to fit all teeth regardless of circumference and height. Available as 4 , 6 and 8 mm thickness bands.

55. HAZARDS OF IMPROPER CONTOURS : Facial and lingual convexities : Overcontoured curvatures can create a favorable environment for the accumulation and growth of cariogenic and plaque bacteria at marginal gingiva ; apical to the height of contour. This results in chronic inflammation of the gingiva.

56. Facial and lingual concavities: Mislocated concavities - premature contacts during mandibular movements E xcessive concavities - extrusion, rotation or tilting of occluding cuspal elements into non-physiologic relations with opposing teeth. Deficient concavities at these locations - can create restoration overhangs which incr eases the chance for plaque retention.

57. Proximal contours: Restoration that does not reproduce the concavities and convexities will lead to restoration overhangs and under hangs, vertical and horizontal impaction of debris and impingement upon the adjacent periodontal structures. Too narrow embrasures predispose to heavier stresses. Too wide embrasures offer little protection to the underlying soft tissue

58. 99

59. CONTACT FORMING INSTRUMENTS These are special instruments designed to create optimum contacts with posterior teeth. Eg: Contact Pro Optra contact

60. CONTACT RINGS Work by providing slight separation of the contacting teeth. Spring action applies equal and opposite forces against the teeth thus providing optimum separation.

61. Palodent Bitine Composi-Tigh t First generation systems

62. Eg :- Composi -Tight 3D soft face ring system V3 ring system. Second Generation Rings

63. PRECONTOURED SECTIONAL MATRIX BANDS

64. Fender Wedges Combination of a steel plate and a plastic wedge. Should be inserted with firm pressure providing a tight stable fit throughout preparation.

65. PRO MATRIX SYSTEM Available as a standard matrix band and a contoured band“ These matrix bands are pre-assembled. They save time and are very convenient.”

66. Conclusion To provide optimum contacts and contours, selection of the matrix should be considered based on its ease of use and efficiency. Proper restoration of the anatomical landmarks is important for enhancing the longevity of restorations as well as to maintain the occlusal health and harmony.

67. REFERENCES TEXTBOOK OF MARZOUK – CLINICAL OPERATIVE DENTISTRY Ashwini, et al.: Clinical considerations in restorative dentistry Journal of the International Clinical Dental Research Organization | July-December 2015 | Vol 7 | Issue 2 TEXTBOOK OF STURDEVANT -THE ART AND SCIENCE OF CLINICAL OPERATIVE DENTISTRY TEXTBOOK OF WHEELERS TEXTBOOK OF VIMAL SIKHRI -THE ART AND SCIENCE OF CLINICAL OPERATIVE DENTISTRY