UCLA perio. dep

1. TARRSON FAMILY ENDOWED CHAIR IN PERIODONTICS

2. UCLA SCHOOL OF DENTISTRY
2

3. Presents
Dr. E. Barrie Kenney
Professor & Chairman
Section of Periodontics
3

4. E. Barrie Kenney B.D.Sc., D.D.S., M.S., F.R.A.C.D.S.
Tarrson Family Endowed Chair in Periodontics.
Surgical Techniques for Crown
Lengthening Professor and Chairman Division of Associated Clinical
Specialties UCLA School of Dentistry

5. 1)Development of Adequate
Indications for Crown Crown Preparation
Lengthening
2)Esthetics

6. Development of Adequate Gingival Margins must not
Crown Preparation invade Biological Width
Requirements for Periodontal
Health.

7. There must be a minimum of
Biological Width 1mm between the apical level
Requirements of the Junctional Epithelium
and the bone crest.

8. Crown Margins which extend An inappropriate crown
apically beyond the Junctional margin increases plaque
Epithelium can violate the accumulation in close
requirements for periodontal proximity to bone crest.
health.

9. Deeply placed crown margins
causing gingival inflammation
and pockets.

10. Both Central Incisors and
right lateral incisor have
crowns violating Biologic
Width concepts.

11. Gargiulo A., Wentz F., Orban F. This study measured
Dimensions and Relations of dimensions of tissues
the Dentogingival Junction in involved in Biological Width
Humans. considerations.
J. Periodontol 1961 32:261

12. Used histologic sections to These are not clinically
measure average dimensions of accurate due to distortion
biologic width. with histologic processing.

13. Sulcus Gingival sulcus 0.69 mm
depth Junctional epithelium 0.97 mm
This study said width of
junctional epithelium plus
Connection tissue 1.07 mm Biologic
attachment coronal to Width connective tissue width was
bone Biologic width; i.e.
approximately 2 mm.

14. However since then it has
been shown that in probing
the sulcus, the probe is
generally at the deepest
position of junctional
epithelium.

15. If a subgingival crown margin
is placed in the middle of the
gingival sulcus, the crest of
bone should be a minimum of
2 mm apically positioned.

16. When a subgingival crown
margin is to be placed it may The necessary for 1 mm of
be necessary to surgically connective tissue between
move the crestal bone margin the epithelium and bone is a
apically so that there is at minimal requirement. Larger
least 2 mm space between the dimensions can be compatible
margin and the bone. with healthy tissues.

17. This is the method of choice
Use of Flap Surgery with
when crown margins will
Osseous Resection impinge on the Biologic
Width.

18. Periapical Radiographs are
needed to ensure sufficient root
length is available. This case
cannot have surgical crown
lengthening and both premolars
need to be extracted.

19. This patient had extensive
tooth wear and loss of Vertical
Dimension

20. There was insufficient clinical
crown volume of the incisors
for adequate retention so flap
surgery was indicated.

22. Prior to Flap Surgery

23. Full thickness labial and lingual
flaps .

24. Bone is recontoured so that 2
mm distance between level of
proposed crown margin and
crest of bone.

25. The lingual side required
minimal bone surgery.

26. Flaps are positioned apically to
increase length of clinical
crowns.

27. Similar apical positioning on
Lingual.

28. Crown preparations 12 weeks
after crown lengthening
surgery.

29. Final upper and lower
restorations.

30. Before After

31. Inadequate clinical crowns for
retention of new restorations.

33. Flap design on buccal.
Intrasulcular incisions, mesial
vertical incision, distal wedge.

34. Flap design on palatal. Reverse
bevel incision removing gingival
margin ,mesial vertical incision,
distal wedge.

36. Buccal full thickness flap
elevation to expose at least 3
mm of crestal bone.

37. Palatal flap elevation to expose
at least 3 mm of crestal bone.

38. The gingival level of new crown
margin is estimated and bone
removed so crestal level is 2
mm apical to this.

39. Buccal crown margins will be
subgingival for esthetics. So
margins will be in middle of
gingival sulcus i.e. 1 mm
coronal to probing depth, add
another 1 mm for connective
tissue to determine bone level.

40. Palatal crown margin will be
supragingival. So allow 1mm
for connective tissue plus 2 to 3
mm for sulcus with bone level 3
to 4 mm apical to level of crown
margin.

41. Buccal flap sutured apically with
increased tooth structure for
crown preparation.

42. Palatal flap repositioned with
continuous sling mattress
sutures and simple U shaped
sutures of distal wedge and
vertical incisions.

43. Buccal Healing at 3 weeks.

44. Palatal Healing at 3 weeks.

45. Crowns placed at 6 weeks.

46. After Before

47. After Before

48. Most cases need flap and
osseous surgery.
Gingivectomy for Crown Gingivectomy used when have
adequate band of Keratinized
Lengthening
tissue and bone crest is
positioned apically with an
initial wide Biological Width.

49. Poor crowns with recurrent
caries.

50. Soft tissue removal will be
adequate for exposure of sound
tooth for margins with a 1 mm
Ferrule Extension.

51. Electrosurgery used for
gingivectomy. This can also be
done with scalpels or laser.

52. Tissue recontoured to expose
root surfaces for adequate
preparation of margins.

53. Provisional restorations at 12
weeks. Marginal gingiva is now
stable so final subgingival
crowns can be completed.

54. Final crown restorations
should not be completed until In esthetic areas a minimum
a minimum of 6 weeks after of 12 weeks after-surgery is
surgery in order to minimized required to be sure no further
further tissue loss due to gingival recession will occur.
trauma of impressions.