Problem Based Learning Pre-prosthetic Periodontal Surgery Maha A. Bahammam, BDS, MSc, CAGS, EdM, DSc Diplomate of the American Board of Periodontology

Case: 1 45 years old. Female patient Healthy Her chief complaint: ( my crowns on my lower RT back teeth always come off, I need good cement this time) What do you think the reason is? And how would you manage that case?

Note where the gingival margin is! Preoperative Postoperative

What is the effect of a restorative margin on the development and health of the supracrestal attachment apparatus?

Success is in the details!

Goals of Osseous Resective Surgery Establish physiologic probing depth Exposing sound tooth structure or correcting an un-esthetic gingival contour

Supracrestal Gingival Tissue (SGT) Bilogic Width: the juctional epithelium and connective tissue elements of the dentogingival contiuum that occupy the space between the base of the gingival crevice and the alveolar crest (Cohen, 1962)

Biologic Width Gargiulo et al. described the dimensions and relation of the dentogingival junction in human. Their study established that there is a proportionate dimensional relationship between the crest of the alveolar bone, the connective tissue attachment, junctional epithelium, and the sulcus.

The biologic width is that zone of root surface coronal to the alveolar crest, to which the connective tissue and junctinal epithelum are attached. Gargiulo A, Wantz F, Orban B. 1961. Dimentions of the dentogindival junction in Humans. J Periodontol., 32, 261.

Biologic Width Sulcus depth- 0.69mm Junctional epithelium- 0.97mm Connective tissue attachment- 1.07mm Total (from the osseous crest to the gingival margin): 2.73mm These are averages!!!

A small amount can make a BIG difference!

How much is enough?

Estimated dimention of the biologic width as being in vicinity of 2 Estimated dimention of the biologic width as being in vicinity of 2.04 mm (Gargiulo et al., 1961) ≈ 2 mm Therefore the total dimensions of SGT (Biologic Zone) would be in vicinity of 2.73 mm. ≈3mm

Based on these dimensions of the SGT Ingber et al., 1977; states that during clinical crown lengthening surgery, sufficient bone should be resected to permit 3 mm of sound tooth structure above the crest of the bone Rosenberg et al., 1980; preferred 4 mm of tooth exposure

This bone resection is necessary to accommodate the SGT, which will develop in the surgical site, and yet leave sufficient tooth exposed to complete the tooth preparation When the attachment levels are within normal limits, soft tissue excision alone will result in reformation of the predestined amount of SGT and no real gain in clinical crown length

The decision to restore a tooth depends on the following factors: Degree of periodontal support lost form adjacent tooth during crown lengthening procedure Location of furcation relative to biologic width Ability to perform effective plaque control following placement of restoration

Continue Crown to root ratio Position of tooth in the arch Predictability of treatment procedure Strategic value of tooth Esthetic and phonetic consideration Endodontic consideration Root anatomy and morphology as it relates to post placement Restorative requirement Cost/ Risk/ Benefit ration relative to alternative treatment (Case 4)

Indications: surgical removal of healthy periodontal tissue is sometimes necessary to facilitate a restorative treatment for the following reason: Tooth decay at or apical to the gingival margin that prevent adequate finish line preparation Tooth fracture bellow the gingival margin, with adequate remaining periodontal support and attachment Teeth with insufficient interocclusal space Mechanical retention is inadequate Displeasing esthetics of short or uneven clinical crown lengths following excessive attrition or delayed passive eruption

Cost/ Risk/ Benefit Ration What are the costs of each treatment? What is the length of time involved? How many visits are involved? What is the long term prognosis? How predictable is the procedure?

How do we treat this case? What do we tell the patient?

How do we treat this case? What do we tell the patient?

Contraindications for Crown Lengthening Procedures Teeth that are not restorable, when adjacent teeth would be compromised either functionally or esthetically When the importance of the tooth is not comparable with the extent of the procedure required to save it.

Post Operative Treatment Perio packing Medication NSAID Antibiotics Analgesics Suture removal Completion of restoratioin

Possible Complication Bleeding Pain Swelling Root sesitivity Loss of flap

How long to wait for healing?

Healing should proceed uneventfully, with the attachment of the flap to the underlying bone being completed by 14 to 21 days. Maturation and remodeling can continue for up to 6 months. It is usually advisable to wait a minimum period of 6 weeks after the completion of the last surgical area before beginning dental restorations. For those patients with a major cosmetic concern, it is wise to wait as long as possible to achieve a postoperative soft tissue position and sulcus that is stable.

The Art of Communication

Explaining the Procedure What words do we use? Cut away tissue Grind bone surgery

Weighing the choices

Cost/ Risk/ Benefit Ratio What alternative treatment exists? Extraction Bridge Implant

Cost/ Risk/ Benefit Ratio What alternative treatment exists? Extraction Orthodontic extrusion

Forced Eruption and Flap Surgery This accomplished by moderate orthodontic force of 25 to 35 g. Indications: When the amount of surgical bone reduction around the affected tooth and the adjacent teeth would be excessive

Contraindication: Short root length which result in inadequate crown/ root ration following extrusion Poor root form

Following forced eruption, a flap procedure usually is necessary to reduce any extruded alveolar bone and to apically position the gingiva that moved coronally during extrusion However, if a gingival supracrestal fibrotomy is performed during the extrusion process, the gingiva should not erupt with the tooth, and the need for periodontal surgery maybe eliminated

Advantages of Forced Eruption Supporting bone of the adjacent teeth not sacrificed Surgical treatment phase maybe reduced or eliminated

Summary In establishing a biologic basis for crown lengthening; we should consider the following: Finish line of the restoration should be determined prior to the surgery If not possible, the finish line should be anticipated at surgery Sufficient alveolar bone should be removed to permit the development of an acceptable dimension of SGT between the actual and anticipated finish line of the preparation and the alveolar crest

Circumferential transgingival probing (bone sounding) prior to surgery, in healthy areas in the operation site, should be the gauge for estimating the SGT compatible with individual patient requirements The degree and configuration of osseous scalloping is determined by the surface topography of the tooth

Gingival form is dictated both by osseous configuration and the surface anatomy of the tooth Restorative procedures must not disrupt the epithelial attachment and the SGT

Conclusions Dental restorations and periodontal health are interrelated The adaptation of the margins, the contours of the restoration, the proximal relationships, and the surface smoothness have a critical biologic impact on the gingiva and supporting periodontal tissues Dental restorations therefore play a significant role in maintaining periodontal health

Thank You!