Presented By Dr. M. Shiva Shanker II Year Post Graduate Student ,

1. Presented By Dr. M. Shiva Shanker II Year Post Graduate Student , Dept of Periodontics, Mamata Dental College.

2. contents • Introduction • Rationale for periodontal therapy • Normal periodontium • Gingiva • Gingival crevice • Biologic width • Irritating factors for the periodontium. • Periodontal-Restorative interrelationship • Biologic considerations: • Contour. • Contact areas • embrasures/spillways. • Overhanging margin. • Margin placement & biologic width. • evaluation of violation of biologic width. • correction of biologic width violation. • margin placement guidelines. • clinical procedures in margin placement • Tissue retraction. • Hypersensitivity to dental materials • Esthetic considerations: • interproximal embrasure form. • Restorative correction of open gingival embrasure. • Conclusion

3. introduction

4. RATIONALE FOR PERIODONTAL THERAPY • Stable gingival margins before tooth preparation(kois 2000) • Perio treatment should antecede restorative care. • Quality, quantity and topography of the periodontium provides structural defense factors in maintaining health.

5. Normal periodontium • Gingiva • Gingival crevice. • Biologic width. Clinical Periodontology - 9th edition, Carranza

6. Irritating factors for periodontium • Prior to procedure • Caries • Teeth separation • Rubber dam Interactions between the gingiva and the margin of restorations,J Clin Periodontol 2003; 30: 379–385.

7. Irritating factors for periodontium conti.. • During the procedure: meticulous instrumentation. • Preparation instrumentation • Vibration • preserving proximal plate of enamel-during gross cavity preparation- avoid injury to gingiva. • Wedges below contact area- before proximal box preparation • Matricing Interactions between the gingiva and the margin of restorations,J Clin Periodontol 2003; 30: 379–385.

8. Irritating factors for periodontium conti.. • Long after the procedure: restoration in close proximity to soft tissue. • Gingival retraction • Physical retraction methods • Chemical retraction methods • Electro surgical procedures • Impression procedures • Temporary restorations & fabrication Interactions between the gingiva and the margin of restorations,J Clin Periodontol 2003; 30: 379–385.

9. Periodontal-Restorative interrelationship Seven characteristics of restorations and partial dentures are important from a periodontal point of view: • Margins of restorations • Contours • Occlusion • Materials • Bridge design • Design of Removable Partial Dentures • Procedures of Restorative Dentistry themselves. Periodontal-Restorative Interactions: A Review, shaveta sood, shipra Gupta, Indian Journal of Clinical Practice , Vol. 23, No. 11, April 2013

10. Interrelationship contd… Margins of restoration • location of restorative margins is determined by many factors • Esthetic concerns. • Need for increased retention form • Refinement of pre-existing margins. • Root caries. • Cervical abrasion • Root sensitivity. Periodontal-Restorative Interactions: A Review, shaveta sood, shipra Gupta, Indian Journal of Clinical Practice , Vol. 23, No. 11, April 2013

11. Interrelationship contd… • Orkin et al 1986 demonstrated that sub gingival restorations had a greater chance of bleeding and exhibiting gingival recession then supra gingival restoration • Waerhaug 1978 stated that sub gingival restorations are plaque retentive areas that are inaccessible to scaling instruments. The restorative periodontal interface: biological parameters. Perio2000 2001;25:100

12. Interrelationship contd… Contours • Over contouring and under contouring • The most common error in recreating the contours of the tooth in dental restorations is over contouring of the facial and lingual surfaces, generally in the gingival third. • Apparently, under contouring is not nearly as damaging to the gingiva as the over contouring. Preparation of tooth surface. Schmid MO, clinical periodontology, 8th edition.

13. Interrelationship contd… • Occlusion • Restorations that do not conform to the occlusion patterns of mouth cause occlusal disharmonies that may be injurious to the supporting periodontal tissues. The restorative periodontal interface: biological parameters. Perio2000 2001;25:100

14. Interrelationship contd… Materials • Restorative materials are not themselves injurious to the periodontal tissues. • The surface of restorations should be as smooth as possible to limit plaque accumulation. • Resins are highly polishable, but have deficiencies in strength, porosity and wear. • Glass ceramics and porcelain veneers offer a clear advantage over any other type of restorative materials in the maintenance of gingival health. • There are clinical situations in which the full crown is indicated prior to restoration. It fulfills requirements that can be met in no other type of restoration. The effect of cervical sub gingival restoration margins on the degree of inflammation of the neighbouring gingiva, Schweiz 1974.

15. Interrelationship contd… Bridge design • The health of the tissues around fixed prostheses depends primarily on the patient’s oral hygiene; the materials with which bridges are constructed appear to make little difference. • Ridge lap pontics, the least desirable design. • Bridge design with the least effect on the periodontium is the sanitary or hygienic pontic. Periodontal conditions and carious lesions following the insertion of fixed prosthesis, Int Dent Journal 1980.

16. Interrelationship contd… Design of Removable Partial Dentures • partial dentures favor the accumulation of plaque, particularly if they cover the gingival tissue. Periodontal and prosthetic conditions in patients treated with removable partial dentures and artificial crowns, Acta Odontol Scand, 1971

17. Interrelationship contd… Restorative Dentistry Procedures Periodontal-Restorative Interactions: A Review, shaveta sood, shipra Gupta, Indian Journal of Clinical Practice , Vol. 23, No. 11, April 2013

18. BIOLOGIC CONSIDERATIONS Contour • Convexity on facial & lingual surfaces: provides protection & stimulation to supporting structures during mastication. • Becker and Kaldahl opined that the buccal and lingual crown contour should be ‘flat’ and not ‘fat’, usually < 0.5 mm, wider than the CEJ. • Yondeliset al demonstrated that greater the amount of facial and lingual bulge of an artificial crown, the more the plaque retained at the cervical margins.

19. BIOLOGIC CONSIDERATIONS contd… Interproximal contacts • There must be a positive contact relation mesially and distally of one tooth with another in each dental arch. • The contact points should be located incisially or occlusally and buccally. • Labio Lingual Location Hazards of broad contact when placed • Occlusogingivally • Narrow Contact • Contact too far gingivally • Contact too far occlusally • Too far buccal/ lingual • Open Contact The restorative periodontal interface: biological parameters, periodontology 2000 2001

20. BIOLOGIC CONSIDERATIONS contd… Embrasures/spillways • V shaped spaces originate at the proximal contact area between adjacent teeth. Functions • Serve as spillways for escape of food during mastication-force brought on the tooth is reduced. • Prevents forcing of food into contact area. The restorative periodontal interface: biological parameters, periodontology 2000 2001

21. BIOLOGIC CONSIDERATIONS contd… Restoration over hangings • Overhanging restorations contribute to gingival inflammation due to their retentive capacity for bacterial plaque. • Gilmore and Sheiham 1971 illustrated interproximal radiographic bone loss adjacent to posterior teeth with overhanging restoration. The restorative periodontal interface: biological parameters, periodontology 2000 2001

22. BIOLOGIC CONSIDERATIONS contd… • Jeffcoat and Howell 1980 demonstrated a link to the severity of the overhang and the amount of periodontal destruction. Based upon radiographic evaluation of 100 teeth with overhang and 100 without, they reported greater bone loss around teeth with large over hangs. The severity of bone loss was directly proportional to the severity of the overhang. • Spinks et al 1986 demonstrated that a motor driven diamond tip is faster for removing over hangs and led to smoother restorations compared to Sonic Scalers and Curettes respectively.

23. BIOLOGIC CONSIDERATIONS contd… MARGIN PLACEMENT AND BIOLOGIC WIDTH • Supragingival • Equigingival • Subgingival Biologic width and its importance in periodontal and restorative dentistry, Babitha Nugala, Journal of Conservative Dentistry,Jan-Mar 2012,Vol 15.

24. BIOLOGIC CONSIDERATIONS contd… Supragingivalmargin • least impact on the periodontium. • Preparation of the tooth and finishing of the margin is easiest • Duplication of the margins with impressions can be done with ease. • Fit and finish of the restoration and removal of excess material is easiest • Verification of the marginal integrity of the restoration is easiest.

25. BIOLOGIC CONSIDERATIONS contd… Equigingival margin • Previous thought: retains more plaque than supra & sub gingival margins therefore results in greater gingival inflammation.

26. BIOLOGIC CONSIDERATIONS contd… Subgingival margin • Greatest biologic risk. • Not as accessible as supra or equi for finishing procedures.

27. BIOLOGIC CONSIDERATIONS contd… Biologic width Kois proposed three categories of biologic width based on the total dimension of attachment and the sulcus depth following bone sounding measurements. • Normal crest patient • High crest patient • Low crest patient. Biologic width and its importance in periodontal and restorative dentistry, Babitha Nugala, Journal of Conservative Dentistry,Jan-Mar 2012,Vol 15.

28. BIOLOGIC CONSIDERATIONS contd… Normal crest patient • Normal Crest occurs approximately 85% of time. • The gingival tissue tends to be stable for a long term.

29. BIOLOGIC CONSIDERATIONS contd… High crest patient • High Crest is an unusual finding and occurs approximately 2% of the time. • Occurs more often in a proximal surface adjacent to an edentulous site.

30. BIOLOGIC CONSIDERATIONS contd… Low crest patient • Low Crest occurs approximately 13% of the time. • Traditionally, the Low Crest patient has been described as more susceptible to recession secondary to the placement of an intracrevicular crown margin.

31. BIOLOGIC CONSIDERATIONS contd… Importance of determining the crest category • This allows the operator to determine the optimal position of margin placement, as well as inform the patient of the probable long-term effects of the crown margin on gingival health and esthetic

32. BIOLOGIC CONSIDERATIONS contd… Margin placement guidelines • Rule I • Rule II • Rule III Margin of restorations-from view point of crown and bridge making, 1972

33. BIOLOGIC CONSIDERATIONS contd… • Orkin et al demonstrated that subgingival restorations had a greater chance of bleeding and exhibiting gingival recession than supragingival restorations. • Renggli et al showed that gingivitis and plaque accumulation were more pronounced in interdental areas with well-adapted subgingival amalgam fillings compared to sound tooth structure. • Flores-de-Jacoby et al studied the effects of crown margin location on periodontal health and bacterial morphotypes in human 6-8 weeks and 1 year post- insertion. Subgingival margins demonstrated increased plaque, gingival index score and probing depths

34. BIOLOGIC CONSIDERATIONS contd… Evaluation of biologic width violation • Clinical method • Bone sounding • Radiographic evaluation

35. BIOLOGIC CONSIDERATIONS contd… Clinical method • Signs of biologic width violation are: • Chronic progressive gingival inflammation around the restoration, • Bleeding on probing, • Localized gingival hyperplasia with minimal bone loss, • Gingival recession, • Pocket formation, • Clinical attachment loss and alveolar bone loss.

36. BIOLOGIC CONSIDERATIONS contd… Bone sounding • The biologic width can be identified by probing under local anesthesia to the bone level and subtracting the sulcus depth from the resulting measurement. If this distance is less than 2 mm at one or more locations, a diagnosis of biologic width violation can be confirmed.

37. BIOLOGIC CONSIDERATIONS contd… Radiographic evaluation • Sushamaand Gourihave described a new innovative parallel profile radiographic (PPR) technique to measure the dimensions of the dento gingival unit (DGU).

38. BIOLOGIC CONSIDERATIONS contd…

39. BIOLOGIC CONSIDERATIONS contd… Surgical crown lengthening • Crown lengthening surgery is designed to increase clinical crown length. Periodontal-Restorative Interactions: A Review, shaveta sood, shipra Gupta, Indian Journal of Clinical Practice , Vol. 23, No. 11, April 2013

40. BIOLOGIC CONSIDERATIONS contd… INDICATIONS • Inadequate clinical crown for retention due to extensive caries, subgingival caries or tooth fracture, • Short clinical crowns. • Placement of sub gingival restorative margins. • Unequal, excessive or unaesthetic gingival levels for esthetics. • Planning veneers or crowns on teeth with the gingival margin coronal to the cemeto enamel junction (delayed passive eruption). • Teeth with excessive occlusal wear or incisal wear. • Restorations which violate the biologic width. • Assist with impression accuracy by placing crown margins more supragingivally.

41. BIOLOGIC CONSIDERATIONS contd… Contraindications • Deep caries or fracture requiring excessive bone removal. • Post surgery creating unaesthetic outcomes. • Tooth with inadequate crown root ratio (ideally 2:1 ratio is preferred) • Non restorable teeth. • Tooth with increased risk of furcation involvement. • Unreasonable compromise of esthetics. • Unreasonable compromise on adjacent alveolar bone support.

42. BIOLOGIC CONSIDERATIONS contd… Gingivectomy • External bevel gingivectomy • Internal bevel gingivectomy Periodontal-Restorative Interactions: A Review, shaveta sood, shipra Gupta, Indian Journal of Clinical Practice , Vol. 23, No. 11, April 2013

43. BIOLOGIC CONSIDERATIONS contd… Apically positional flap surgery Indication • Crown lengthening of multiple teeth in a quadrant or sextant of the dentition, root caries, fractures. Contraindication • Apical repositioned flap surgery should not be used during surgical crown lengthening of a single tooth in the esthetic zone. Periodontal-Restorative Interactions: A Review, shaveta sood, shipra Gupta, Indian Journal of Clinical Practice , Vol. 23, No. 11, April 2013

44. BIOLOGIC CONSIDERATIONS contd… Apically repositioned flap without osseous resection • This procedure is done when there is no adequate width of attached gingiva, and there is a biologic width of more than 3 mm on multiple teeth.

45. BIOLOGIC CONSIDERATIONS contd… Apical repositioned flap with osseous reduction • This technique is used when there is no adequate zone of attached gingiva and the biologic width is less than 3 mm. • The alveolar bone is reduced by ostectomy and osteoplasty, to expose the required tooth length in a scalloped fashion, and to follow the desired contour of the overlying gingiva.

46. BIOLOGIC CONSIDERATIONS contd… • Sugumari et al. in a report on surgical crown lengthening with apical repositioned flap with bone resection performed in the fractured maxillary anterior teeth region, showed satisfactory results both in terms of functional (restoring biologic width) and esthetic outcomes. • Most authors agree that a minimum distance of 3mm is required from the osseous crest to the final restorative margin following a crown – lengthening procedures to allow the margin to finish supra gingivally (Bragger et al 1992).

47. BIOLOGIC CONSIDERATIONS contd… Orthodontic techniques • Heithersay and Ingber were the first to suggest the use of “forced eruption” to treat “non-restorable” or previously “hopeless” teeth. • Forced eruption with minimal osseous resection, and forced eruption combined with fiberotomy (starr). • Frank et al. described forced eruption of multiple teeth. Contraindications • Inadequate crown-to-root ratio • Lack of occlusal clearance for the required amount of eruption

48. BIOLOGIC CONSIDERATIONS contd… Tissue retraction • Retraction cord • Tissue management is achieved with gingival retraction cords, using the appropriate size to achieve the displacement required. • Rule 1 margin • Rule 2 margin

49. BIOLOGIC CONSIDERATIONS contd… Various chemicals used for the treatment of chords include: • 0.1% and 8% recemic epinephrine • 100% aluminum solution (potassium aluminum sulfate) • 5% and 25% aluminum chloride solution • Ferric subsulfate (Monsel’s solution) • 13.3% ferric sulfate solution • 8% and 40% zinc chloride solution • 20% and 100% tannic acid solution • 45% negatol solution.

50. BIOLOGIC CONSIDERATIONS contd… Recent Advances Merocel • Made of a synthetic material that is specifically chemically extracted from a biocompatible polymer (hydroxylate polyvinyl acetate) that creates a net like strip (2 mm thick) Expasyl • Composed of micronized kaolin, aluminum chloride and water