Iatrogenic factors in periodontal disease

periodontology

1. Iatrogenic Factors in Periodontal Disease Prepared by: Lobna El Saadawy

2. Outline Definition Common factors: Margins of the restoration Contour and open contact Restorative material Design of the removable partial denture Restorative dentistry procedure Malocclusion Orthodontic therapy Extraction of impacted third molar Habits and self-inflicted injuries Radiation therapy

3. Definition Inadequate dental procedures that contribute to the deterioration of the periodontal tissues are referred to as iatrogenic factors

4. 1. Margins of the restoration Overhanging restoration Location of the margin Marginal roughness

5. A) Overhanging margins 1 ) Inhibit the patient’s access to remove accumulated plaque

6. Overhanging margins Change the ecologic balance of the gingival sulcus to an area that favors the growth of disease-associated organisms (predominately gram negative anaerobic species ) at the expense of the health associated organisms (predominately gram-positive facultative species )

7. B) Location of the gingival margin Subgingival margins Equigingival margins Supragingival margins Severe gingivitis and deep pockets Less severe gingivitis Normal as in natural teeth

8. C) Marginal Roughness Sources of marginal roughness include Grooves and scratches in the surface of even a carefully polished restoration ex: porcelain or gold restoratian

9. c) Marginal Roughness Sources of marginal roughness include Inadequate marginal fit of the restoration * subgingival margins typically shows a gap of 20-40 um between the margin of the restoration and the unprepared tooth surface that favors bacterial plaque colonization

10. C) Marginal Roughness Sources of marginal roughness include: The gap that exposes the rough prepared tooth structure following the dissolution of the luting cement at the restoration margins SEM photomicrograph of the cervical margin of a 5-year old porcelain veneer (P) showing a small marginal defect and a border of roughened porcelain (arrows). (G, gingiva ; C, luting composite)

11. 2. Contour and Open Contacts Overcontoured Crowns Buccal and lingual contours Occlusal contours Inadequate interproximal embrasure

12. Overcontoured Crowns Overcontoured crowns and restorations tend to accumulate plaque and possibly prevent the self-cleaning mechanisms of the adjacent cheek, lips, and tongue

13. Overcontoured Undercontoured a) Buccal and Lingual Contours Prevent self cleansing mechanism of the cheeks, lips and tongue Does not have that much destructive effect

14. But under contoured restorations with absent or shallow buccal deflection ridge are said to cause gingival trauma due to injury by rough food

15. b) Occlusal Contours Established by marginal ridges and related developmental grooves. Normally they deflect food away from the inter proximal spaces

16. Occlusal Contours Inappropriate occlusal contours leads to Food impaction Plaque retention Food impaction is defined as the forceful wedging of the food into the periodontium by occlusal forces Cusps that tend to forcibly wedge food into interproximal embrasures are known as plunger cusps .

17. Occlusal Contours Factors leading to food impaction made by Hirschfeld : Uneven occlusal wear. Open contact area as a result of the loss of proximal support or from extrusion Congenital morphologic abnormalities Improperly constructed restorations

18. Inadequate interproximal embrasure associated with papillary inflammation

19. 3. Restorative Material

20. Restorative materials are not in themselves injurious to the periodontal tissues. One exception to this may be self-curing acrylics Plaque retention capacity of different restorative materials is different but yet can be controlled if the restoration was well polished and was accessibile to oral hygiene measures

21. The undersurface of pontics in fixed bridges should barely touch the mucosa. Access for oral hygiene is inhibited with excessive pontic to tissue contact .

22. 4. Design of Removable partial denture

23. Removable partial dentures favor plaque accumulation resulting in: gingival inflammation periodontal pocket formation mobility of the abutment teeth.

24. Partial dentures that are worn during both night and day induce more plaque formation than those worn only during the daytime The presence of removable partial dentures induces both quantitative and qualitative changes in dental plaque promoting the emergence of spirochetal microorganisms

25. Spirochetes are gram-negative bacteria that are long, thin and spiral-shaped. some of them are pathogenic to humans . There is one species of spirochete that is part of the natural environment of the human mouth called Treponema denticola . Although T. denticola is typically not harmful,but under certain conditions , it may play a role in the progression of periodontal disease It is one of the red complex pathogens .

26. 5. Restorative Dentistry Procedures

27. The use of rubber dam clamps , matrix bands , and burs in such a manner as to lacerate the gingiva results in varying degrees of mechanical trauma producing transient injuries that generally undergo repair

28. Forceful packing of a gingival retraction cord into the sulcus to prepare subgingival margins on a tooth or for the purpose of obtaining an impression may mechanically injure the periodontium and leave behind impacted debris capable of causing a foreign body reaction.

29. 6. Malocclusion

30. Irregular alignment of teeth results in more difficult plaque control Several authers found a positive correlation between crowding & periodontal disease but others didn’t find any correlation.

31. Occlusal Disharmonies Restorations that doesn’t conform to the occlusal pattern of the dentition may cause injury to the supporting periodontal tissues (traumatic occlusion – T.F.O.) H istological features of the periodontium of atooth subjected to T.F.O. : widened PDL space , Reduction in the number of collagen content in oblique and horizontal fibers increase in vascularity and leukocyte infiltration , increase in the number of osteoclasts on bordering alveolar bone .

32. Failure to replace posterior teeth After the extraction of mandibular 1 st molar with the failure to replace : 1) the initial change is a mesial drifting and tilting of the mandibular second and third molars 2) extrusion of the maxillary first molar

33. Failure to replace posterior teeth 3) As the mandibular second molar tips mesially , its distal cusps extrude and act as plunger 4) The distal cusps of the mandibular second molar wedge between the maxillary first and second molars and open the contact by deflecting the maxillary second molar distally.

34. 7. Periodontal complications associated with orthodontic therapy Direct effect Indirect effect

35. I. Indirect Effect Favoring plaque retention and food debris.

36. ii. Modifying the gingival ecosystem resulting in gingivitis An increase in Prevotella Odontolyticus Prevotella Intermedia Actinomyces Odontolyticus Aggregatibacter actinomycetemcomitans * With the decrease in facaulitative microorganisms

37. direct effect Creating excessive and/or unfavourable forces on teeth and supporting structures Excessive force produce: necrosis of PDL and adjacent alveolar bone increase the risk of apical root resorption Risk factors for root resorption include : magnitude of force ,duration of treatment , continous versus intermittent force . Direction of tooth movement ??????

38. ii. Orthodontic bands placed on newly erupted permanents with still attached junctional epithelium on enamel will result in apical migration & proliferation of the junctional epithelium and an increased incidence of gingival recession

39. The mean alveolar bone loss for adolescents who under went 2 years of orthodontic treatment ranges from 0.1- 0.5 mm (this is found to be of little significance) as that also noted for the control groups The degree of bone loss during adult orthodontic care may be higher than that observed in adolescents, especially if the periodontal condition is not treated before initiating orthodontic therapy .

40. III. Other effects ($) Surgical exposure of impacted teeth and orthodontic-assisted eruption has the potential to compromise the periodontal attachment on adjacent teeth . However , those teeth have more than 9o% of their attachment remains intact

41. ($) It has been reported that the dentoalveolar gingival fibers that are located within the marginal and attached gingiva are stretched when teeth are rotated during orthodontic therapy Surgical removal of these gingival fibers in combination with a brief period of retention may reduce the incidence of relapse after orthodontic treatment intended to realign rotated teeth

42. 8) Extraction of impacted third molars

43. Extraction of impacted third molars often results in 1) the creation of vertical defects distal to the second molars However this iatrogenic effect is unrelated to flap design *B ut it’s related to presence of plaque , bleeding on probing , pathologically widened follicle , inclination of third molar , root resorption of 2 nd molar * it appears to occur more often when third molars are extracted in individuals older than 25 years.

44. 2) Another consequence of removal of third molars include permanent paresthesia (numbness of the lip, tongue, and cheek), d.t injury of the lingual nerve passing distal to third mandibular molar

45. 9 . Habits and Self Inflicted Injuries

46. Tooth brush trauma Acute Erosions & diffuse erythema Ulcers Acute gingival abscess d.t. forcefully embeded tooth brush bristle history : Signs of acute gingival abrasion are frequently noted when the patient first uses a new brush Chronic Buccal and lingual recession and attachment loss Cervical abrasion

47. II . Chemical Injury 1) allergic inflammatory states, the gingival changes range from simple erythema to painful vesicle formation and ulceration. E.x . mouthwashes , dentifrices, or denture materials are often explain 2) nonspecific injurious effect of chemicals on the gingival tissues. * topical application of corrosive drugs such as aspirin , phenol or silver nitrate

48. III. Tobacco use It results in : 1) oral leukoplakia 2) Increased incidence of gingival recession, 3) cervical root abrasion, and root caries 4) high incidence of severe periodontitis

49. 10. Radiation Therapy

50. Radiation Therapy Radiation therapy has cytotoxic effects on both normal and malignant cells The typical total dose of radiation for head and neck tumors is in the range of 5000 to 8000 centiGrays ( cGy = 1rad) The total dose of radiation is given in partial incremental doses ( Fractionation where the typical dose administrated is in the range of 100 to 1000 cGys per week). this helps to minimize the adverse effects of the radiation while maximizing the death rate of the tumor cells.

51. Radiation therapy induces Obliterative Endarteritis resulting in: Soft tissue ischemia and fibrosis Hypo vascular and hypoxic bone Osteoradionecrosis Dermatitis and mucositis muscle fibrosis and trismus (restricting access to oral cavity) Xerostomia (greater plaque accumulation) Caries periodontal attachment loss and teeth loss Greater risk to periodontal infections

52. How to prevent the complications of radiotherapy? 1. The severity of the mucositis can be reduced by asking the patient to avoid secondary sources of irritation to the mucous membrane, such as smoking, alcohol, and spicy foods.

53. 2. Use of a chlorhexidine digluconate mouthrinse may help reduce the mucositis . However, chlorhexidine mouthrinses having a high alcohol content that may act as an astringent , which dehydrates the mucosa, thereby intensifying the pain.

54. Fluoride application, effective oral hygiene measures and frequent dental examination . Consult the oncologist before any surgical or periodontal procedure to decrease incidence of osteoradionecrosis Prophylactic antibiotics to avoid osteomyilitis Restricted use of local anesthetic with vasoconstrictor . Hyperbaric oxygen therapy for treatment of osteoradionecrosis

55. Complications of the Use of Laser in Periodontology

56. Pitting and crater formation in cementum Exposure of dentinal tubules , and cementum “peeling” A reduced attachment of fibroblasts to Nd:YAG laser treated cementum was observed Nd:YAG  ( neodymium-doped yttrium aluminum garnet ;  Nd:Y 3 Al 5 O 12 )

57. In conclusion the use of the Nd:YAG laser in periodontal treatment is restricted to the area of the soft tissue management. No safe removal of calculus is possible using a Nd:YAG laser.

58. Erbium:YAG laser Roughness of the enamel surface after Er:YAG laser irradiation

59. After irradiation with the Er:YAG laser enamel prisms at the rugged surface are clearly visible, the border between lased and non lased surface can be seen

60. Calculus is removed from cementum using an Er:YAG laser, the irradiated track is visible, the upper layer of cementum is removed, too calculus cementum dentine

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