PROCEDURAL FAILURES

PROCEDURAL FAILURES

• Pre-therapeutic
• Therapeutic
• Post therapeutic

PRE-THERAPEUTIC

• Incorrect patient selection:
  • Age : older v/s younger  prognosis is better in younger individuals
  • Socio-economic status indirectly reflect on the periodontal therapy outcome as a poor patient may not be able to afford invasive procedures and also they may have nutritional deficiencies which hampers the wound healing.
  • Persistent poor oral hygiene/poorly motivated patient
  • Smoker :failure to quit smoking
• Patients with systemic diseases like diabetes mellitus, blood dyscrasias like leukemia, cyclic neutropenia, immune deficiencies like neutrophil monocyticchemotactic defects, aids, genetic disorders like down’s syndrome, papillion- lefebvre syndrome, hypophosphatasia, chediak higashi syndrome and vitamin deficiencies may have poor prognosis hence care should be taken when such patients are taken up for extensive periodontal surgeries
• Inappropriate or improper dental restorations or prosthesis
  • Overhanging class II restorations, overextended crowns & bridges can lead to failures in periodontal therapy.
• Failure to carry out associated prosthetic restorative procedure
  • Failure to replace the missing teeth will lead to excessive stresses over the remaining natural teeth; secondly there will be selective intake of diet leading to nutritional deficiencies thus hampering the post therapeutic healing
• Morphology of tooth surface
  • Morphological aberrations like resorption lacunae lateral accessory canals, enamel pearl and grooves can act as a “guide plan” for bacterial penetration into deeper periodontal tissues, thus compromising a success.
• Habits
  • Habits like mouth breathing, bruxism (clenching and grinding), and thumb sucking and smoking are associated etiological factors which if untreated, will lead to therapeutic failure.
• Occlusal corrections or teeth preparations
  • Occlusal discrepancies may lead to trauma from occlusion. Failure to eliminate or correct these occlusal discrepancies either by orthodontic or  occlusal adjustment or selective grinding

THERAPEUTIC

• Non-surgical
  • Scaling, root planning, splinting, occlusal therapy&local drug delivery.
• Surgical
  • Curettage, gingivectomy, abscess drainage, flap surgery, bone grafts, gtr procedures, root coverage procedures, implant & aesthetic surgeries,implants

Nonsurgical : incomplete/inappropriate treatment

• Scaling : Persistence of inflammation because of residual embedded calculus.
• Abscess formation can also be noticed in situations wherein residual calculus is embedded in the tissues
• Causes:
  • Incorrect instrumentation : leading to improper removal, reduce the efficiency of instrument as well as gouge the root surface.
  • Poor condition of instruments or worn out instruments: burnishing of calculus
  • Burnishing calculus: cause :  instrument not properly angulated or adapted:
• Inadequate accessibility & visibility :
• Deep pockets
• Complex anatomical areas of the tooth like the furcation areas, grooves & concavities present on the root surface.

Ultrasonic scaling

• Improper water setting, tip selection and scaling strokes
• Improper angulation of tip on tooth surface can cause scratches of tooth surface
•  the active tip to tooth angle should be maintained at 15° or less 
• Root planning
  • Failure of scaling is obviously recognized by rough root surfaces and persistence of inflammation.
• Causes:
  • Over instrumentation of root surface removes the unaltered cementum and may result in exposure of dentin especially in the cervical regions where the cementum is the thinnest. This may result in sensitivity and the area may also be prone for root caries.
  • If there is a developmental groove, it impedes the root planning, thus smoothening as far as possible with the use of rotary instruments may go as long way in achieving success.

Local delivery:

• Forceful insertion of local delivery agent : resulting in abscess formation
• Wash out of local delivery drug : periopack can be placed to hold the agent
• Difficulty in placing the ldd in inaccessible, deep pockets and in furcations.
• Development of resistance among bacterias
• Time consuming and expensive if many sites are involved with periodontal disease.

Splinting

• Failures could be reflected as inflammation in the area
  • Breaking of splints and increased plaque accumulation
• How to prevent?
  • Check for the following
    • Contouring the splint
    • Proximal cleaning aids to enhance plaque control.
    • Should be clear of occlusal interferences.
    • Margins of splint should be flush with tooth surface
    • Splints should not interfere with masticatory or speech function
    • Splints may generate torsional forces and may result in tooth movement so care should be taken

Occlusal therapy

• The severity of occlusal disturbances must be analysed and treated accordingly; either orthodontically or prosthodontically.
  • Patients with other oral habits like tongue thrust, occupational habits must be either advised to quit or forced to quit before attempting any periodontal therapy.
  • Gross malocclusion must be corrected following basic therapy.

SURGICAL

• Improper selection of surgical technique:
  • Factors such as width of attached gingiva, height of remaining bone, pocket depth, mobility, cooperation of the patient, systemic background etc should determine the choice of technique.
  • Improper asepsis of the surgical field and patient, improper sterilization of instruments, use of unsterile medicaments, mouth masks, gloves etc. Will lead to infection and consequent failure in periodontal treatment

Abscess and drainage

• Failures of abscess drainage are defined by the recurrence of abscess/ resultant increase in periodontal destruction

Causes and prevention:

• Proper identification of the source/ origin generally prevents recurrence of abscess. The tortuosity of the pocket and the complexity of the tooth anatomy require a precise identification and source of the abscess prior to the drainage.
• Removal of the entire abscess wall is mandatory, as remnant tags could act as a nidus, surrounding which recurrent abscesses can occur
• Chronic abscesses tend to show more recurrence.
• Systemic antimicrobials is mandatory especially if it’s a periodontal abscess.
• A gingival abscess is usually exogenous in origin either by the incorporation of a foreign body into the gingiva or as a result of trauma .
• Its drainage and removal usually is uneventful and seldom requires antibiotics

Curettage

• Failure following curettage is determined by the persistence of inflammation after therapy.

Most likely causes are :

•  procedural errors
• Thus, the adaptation of the cutting edge to the tissue is important and the finer pressure on the other side of the flap must preferably be a nail bed as this is a relatively firm surface.
• The strokes when given should be with a firm lateral and coronal pressure with the instrument held parallel to the tissue surface. Turning the instrument edge could result in tearing or flap perforation.
• Sometimes, the operator is not aware whether he has completely removed the granulation tissue as it is often a blind procedure. A good indicator of when to stop the procedure would be to detect if any persistent bleeding arises from the tissue margin.
• The bleeding would generally stop if the complete removal of granulation tissue is accomplished.

Failure to irrigate :

• Curetted area must always be forcefully irrigated and failing to do so, may leave behind tags of granulation tissue which may either be resorbed or may increase the tissue volume preventing the formation of a knife-edged gingival margin

Failures associated with depigmentation

• If the procedure of depigmentation is carried out with electrocautery, care should be exercised to prevent necrosis of bone. So, contact of the cautery instruments with underlying bone hould be avoided.

If chemicals are used to produce depigmentation, there may be damage to the bone and underlying tissue because the depth of action of these chemicals is not controlled

Gingivectomy

• Failures in gingivectomy could be defined by recurrence of lesion either immediately or within a few weeks usually by destruction of the periodontal apparatus.

Causes and prevention

• Failure to eliminate etiology of enlargement will result in recurrence.
• External bevel incision is desired except in inaccessible areas; as this allows for thinning of the gingiva to a knife edge resulting in excellent postoperative healing.
• When using electrocautery; avoid contact with bone as this may lead to degenerative and necrotic changes in bone tissue

Wade (1954) outlined  15 reasons why gingivectomy fail

1.unsuitable case selection: cases with underlying osseous irregularities or intrabony defects

2. Incorrect pocket markings

3. Incomplete pocket elimination

4. Insufficient beveling of the incision

5. Failure to remove tissue tags, resulting in excessive (granulation) tissue

6. Failure to remove etiologic factors—calculus and plaque

7. Beginning or terminating the incision in a papilla

8. Failure to eliminate or control the predisposing factors

9. Inaccessible interdental spaces

10. Loose dressings

11. Lost dressings

12. Insufficient use of dressings

13. Failure to prescribe stimulators or rubber tipping for interproximal use

14. Failure to use stimulators or a rubber tip

15. Failure to complete treatment

Flap surgical techniques

• Failures should be identified by recurrence of pockets, flabby tissue, abscess formation, gingival recession, cleft formation, loss of interdental papilla etc. In most situations, some amount of gingival tissue recession and loss of papilla may occur, however this should be very minimal.
• Causes and prevention
• Inaccurate flap design-hence proper technique should be executed.
• Incomplete debridement of granulation tissue and deposits especially in areas of complex tooth anatomy like furcations (especially maxillary mesial and distal furcations) can lead to residual granulation tissue and deposits.
• Inaccurate adaptation of flap to tooth and bone.
• Improper placement of the flap to its original position. This may lead to post-operative pain and different tissue form following surgery
•  improper closure leads to leakage of the grafted materials
• Excessive reflection can cause increased postoperative bone resorption due to the strain relaxation effect produced by a loosening of packing of collagen fibers.

Prevention:

• Correction of bony ledges, failure to detect and assess furcation involvements could lead to improper maintenance by the patients predisposing the patients to secondary periodontal infections and attachment loss.
• Achieve good primary closure using adequate number. Of sutures.
• Placement of pack, though controversial in non-regenerative techniques may provide additional support to the healing periodontal wound.

Failures associated with papilla preservation flap

• Presence of too narrow interdental space: instead use modified papilla preservation and simplified papilla preservation flap
• Incisions should be placed without compromising the blood supply,
• While suturing, flap should be adapted properly, if not, there will be gaping of the flap & failure of regeneration.

Failures in osseous surgery

• Failure of osseous surgery is related to recurrence of pockets or/and excessive loss of bone,

Causes:

• Incomplete pocket elimination resulting from failure to create ideal bone form.
• Improper flap management.
• Sequestration or resorption of bone caused by excessive surgical trauma.
• Improper placement of periodontal pack.
• Exposure of thin bony plates, alveolar dehiscences or fenestrations during surgery.
• Root caries or pulpal problems

Regenerative technique : eg :bone grafting procedures

Pre-surgical considerations 

• Necessity for a bone substitutes.
• Assessment of defect morphology
• Furcation involvement.

Technique of placement-placing it in increments, compacted not condensed, pore size or distance between particles all are very significant, and have a great impact on the success of a surgical procedure.

Maintenance of vascular continuity.

• Decortication of bone by doing trephination will improve vascularity to the surgical site.

Overfilling the defect lead to fibrous encapsulation of the graft

• Persistent ooze from the surgical site displaces the graft material.
• Postoperative infection controlled by antibiotics & antibacterial mouth rinse.
• Adequate sterilizationof the equipment’s,bone substitutes and surgical instruments.
•  primary closure with no intervening graft particles

GTR PROCEDURES

• Adaptation of membrane to provide adequate space to the periodontal ligament cells to migrate and prevents the bone graft particles from collapsing.
• Trimmed membrane should cover at least 2mm of adjacent alveolar bone with no sharp edges.
• Membrane exposure leads : bacterial accumulation which hampers healing
• Membrane sutured by using sling suture

Barrier-independent factors

• Poor plaque control, smoking, occlusal trauma, sub optimal tissue health (i.e. Inflammation persistent),traumatizing habits (e.g.aggressive tooth brushing),overlying gingival tissue, inadequate zone of keratinized tissuesand thin gingival phenotype.
• Surgical technique-improper incision, traumatic flap elevation and management ,excessive surgical time, inadequate closure or suturing
• Post-surgical factors- plaque recolonization, mechanical insult- loss of wound stability (loose sutures, loss of fibrin clot)

Barrier – dependent factors

• Inadequate root adaptation (absence of barrier effect)
•  improper asepstic techniques,
• Instability (movement) of barrier against root
•  premature exposure of barrier to oral environment and microbes,
•  premature loss or degradation of barrier

Growth factor usage

• Method of drawing of blood influences the quality of the prp obtained,use of thrombin and its ratio 1:7 is ideal, when aspiration technique is used platelets are fragile.
• When used alone it will invariably fail to show desired results.
• Prp/prf should be used immediately as soon as it is procured; otherwise it leads to premature cell lysis/degradation of fibrin network/poor gf content

Root coverage procedures

Pre-surgical considerations

• Position of the tooth & Extent of malocclusion present : traumatic occlusion can lead to gingival recession
• Thickness of the gingiva/gingival biotype : thin biotype is more prone to recession over thick biotype
• Depth of the vestibule:  inadequate depth of vestibule interferes with root coverage  
• Width of attached gingiva: needed for predictable root coverage results  

Failures associated with soft tissue augmentation /root coverage surgery

• Mismatch between graft size and defect: if the denuded root defect is small enough, the collateral circulation will be adequate to support bridging.
• Prominent roots, with relatively wide areas of root exposure : collateral circulation is insufficient for the graft support: the center of the graft thins and becomes necrotic; the graft splits and ultimately fails.
• Improper graft adaptation
• All fat and glandular tissue be removed prior to suturing to prevent possible necrosis and/or inadequate take.  Even though the need for this has been questioned, it is still generally accepted
• Graft movement as a result of inadequate or insufficient suturing will surely result in failure because no plasmatic diffusion will occur.
• Root conditioning of the orot surface

The final failure is often seen only after the graft has healed.

• Improper graft handling could be one of the major reasons for failure.
  • Squeezing of the graft leads to leakage of the plasmatic fluid leading to desiccation,
  • The size of the graft should be adequate (the ideal size should be 1.25-1.5 mm)
  • The presence of clot between the graft and root surface, compression of graft against root surface – all these play a role in the success of the procedure.
  • Root conditioning is a must especially in soft tissue graft procedures
• Rotated flaps
  • Maintain viability of papilla.
  • Cut-back incision to prevent tissue ledges.
  • Partial thickness is desired as this may prevent donor site recession.
• Coronally displaced flaps :
  • Causes of failure  :
  • Secured in tension and are not stable; thus vertical incisions play a critical role in the success of this procedure.
• Laterally positioned flap
• Common reasons for failure
  • Tension of the flap
  • Pedicle too narrow
  • Exposure of bone at radicular surface
  • Poor stabilization
• Double papilla flap
• Common reasons for failure
  • Non- union of component flaps
  • Full thickness flap lead to dehiscence or fenestrations
  • Inadequate attached gingiva in the papillary area
  • Proper placement of the flap on periosteal bed
  • Adequate fixation of the flap to prevent shifting
• Free soft tissue grafts
  • Epithelialized grafts-the sutured graft should always be either at the level or higher than the level of adjacent recipient bed but never below as this leads to graft rejection.
  • Recipient bed preparation should be beveled and broader at the base.
• Sub epithelial connective tissue
  • Two techniques of procurement of graft; separation full thickness yields more connective tissue and easier.
  • Grafts have to be trimmed and the lipid layer has to be removed.
  • Tunnel technique gives only marginal recession  coverage as opposed to pouch technique

Implant therapy

• Inadequate contiguity of bone and implant at the time of surgical insertion
• Improper biomaterials
• Use of dissimilar materials
• Bio-incompatible materials
• Contamination of the implant surface and infection
• Surgical over heating of the bone
• Structural design that does not transmit forces evenly to the bone
• Premature loading with occlusal forces prior to healing phase
• Increased periodontal pocket activity

POST THERAPEUTIC

• Instruction & motivation
• Preservation of the periodontal health requires a positive maintenance programme
• If the periodontist executes a very good therapeutic procedure and if the patient does not maintain or is not under proper recall visits it can lead to signs of failures such as bone loss and clinical loss of attachment.
• Motivation and reinforcement of oral hygiene instructions.

Failure to continue with treatment

• Unsupervised healing: absence of supervision…
• Professional cleaning of supragingival area periodically
• Failure to assess oh status.
• Inability to monitor nutritional status
• Inadequate restorations following periodontal therapy
• Failures in periodontal therapy are quite common it may be due to any of the following, inappropriate patient selection, incomplete diagnostic procedures, errors in diagnosis or prognosis, treatment difficulties, unsupervised healing and the absence of maintenance therapy may be causes of such failures.
• A regular recall program can largely prevent such failures and pave the way for improved periodontal health.
• Likewise, critical analysis of different procedures goes a long way in the diagnosis and treatment planning leaving minimal scope for failures in periodontal therapy.

Contributor– Dr. Priyanka Jairaj Dalvi