1. Implant Prostheses in Patients with Bruxism
ปิ่นหทัย กันตะวงษ์

2. Bruxism and Implant failure
Biological failure
Mechanical
failure
Peri implantitis
Peri-implant mucositis
One or more components of an implant system fail
Fracture of implant
Loosening or fracture of connecting screws or abutment screws
Loosening or excessive wear of mesostructures in overdentures
Excessive wear or fracture of suprastructural porcelain or acrylic teeth
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

3. Implant Failure Implant failure Pain during function after healing
Clinical mobility
Radiographic bone loss
Probing depths accompanied by signs(e.g., radiographic radiolucencies, purulent exudate, bleeding) and/or symptoms (e.g., discomfort, pain)
Peri-implant Disease with/without swelling, bleeding and purulent exudate
Loosening or fracture of connecting screws or abutment (screws)
Fracture of suprasructures
Carl E. Misch. (2008). Implant Success, Survival, and Failure:The International Congress of Oral Implantologists (ICOI) Pisa Consensus Conference. IMPLANT DENTISTRY. 17(1), 5-9.

4. This definition encompasses clinical situations
Implant Failure
Implant failure
This definition encompasses clinical situations
The status of the implant performance that when using some quantitative measurement and falls below an acceptable level
S. Salah and C.Paul. (2011, Jan). Implant failure: Etiology and complications. Med Oral Patol Oral Cir Bucal. 16(1);

5. Implant Failure Implant failure
Parameters used for evaluating implant failure
Clinical signs of infection : swelling, fistula, suppuration
Clinically marked mobility : horizontal vertical and rotation mobility
Radiographic signs of failure : Taking periapical radiographs with bite guide before and after treatment
S. Salah and C.Paul. (2011, Jan). Implant failure: Etiology and complications. Med Oral Patol Oral Cir Bucal. 16(1),

6. Periotest for testing horizontal mobility
Implant Failure
Implant failure
Periotest for testing horizontal mobility

7. Radiographic signs of failure
Implant Failure
Implant failure
Radiographic signs of failure

8. Implant Failure Implant failure Etiologic factors:
Infection by plaque accumulating or peri-operative contamination
Peri-implant mucositis : Inflammation in the soft tissue surrounding implants
Peri-implantitis : inflammatory reaction with loss of supporting bone surrounding implants
S. Salah and C.Paul. (2011, Jan). Implant failure: Etiology and complications. Med Oral Patol Oral Cir Bucal. 16(1),

9. Implant Failure Implant failure Etiologic factors: Impaired healing
Surgical trauma (lack of
irrigation and overheating)
Micromotion
Local and systemic characteristics of the host
S. Salah and C.Paul. (2011, Jan). Implant failure: Etiology and complications. Med Oral Patol Oral Cir Bucal. 16(1),

10. Implant Failure Implant failure Etiologic factors: Overload
From unfavorable loading conditions
From poor prosthetic design
Other factors : poor surgical technique, poor bone quality
S. Salah and C.Paul. (2011, Jan). Implant failure: Etiology and complications. Med Oral Patol Oral Cir Bucal. 16(1),

11. Mechanical failures
Center for treatment of periimplant disesase

12. Mechanical failures 1.)Presence of a prosthetic extension/ cantilever
2.) Connecting implants to natural teeth
3.)Malposition or angulation of an implant

13. 1.)Presence of a prosthetic extension/ cantilever
Problems with the availability of bone for placing implants have made cantilever prostheses necessary.
Although cantilevers have been used for years , their use has been discouraged because of the potentially destructive torque and rotational forces that may impart to the abutment teeth

14. It has been hypothesized that the presence of load bearing cantilevers increases the forces distributed to the implants, possibly up to 2 or 3 times the applied load on a single implant, due to bending moments

15. A large fraction of the forces will be transferred to the nearest implant with increasing cantilever length, particularly on distal implants
Imply that, in distal cantilever situations the distal implants will be subjected to the highest loads.

16. in vitro studies supported this hypothesis “The few clinical investigations available have not been able to correlate bone loss around distal implants and cantilever length, but observed more bone loss and implant failures especially at the distal implants, when the anterior area was left without occlusal contact”

17. In contrast, Lindquist et al. and Ahlqvist et al
In contrast, Lindquist et al .and Ahlqvist et al. observed more bone loss around the mesial implants in comparison with the distal implants supporting a fixed complete prosthesis.
Wismeijer et al also demonstrated significantly more bone loss around the mesial implants in comparison with the distal implants in overdenture cases

18. The length of cantilever arm varies from study to study and no clear criteria have been advanced
The recommendations have been largely subjective as no long term controlled clinical study have related implant failure to cantilever length

19. 2.) Connecting implants to natural teeth
Most concerns focus on intrusion of splinted teeth and vertical bone loss around implant abutments .
An implant mobility only10 μm, due to bone flexure, the PDL may allow a tooth mobility of 50 to 200 μm
This mobility difference induce a fulcrum-ike effect and overstress the implant or surrounding bone

20. Non-rigid tooth-implant connection
The use of non-rigid attachments when connecting implants to natural teeth has been suggested to overcome this problem .
However complications, mainly tooth intrusion
The tooth intrudes, the sliding attachment between the implant and tooth may bind, and thus not allow the tooth to rebound, resulting in intrusion

21. Rigid tooth-implant connection
Van Osterwyck et al ,Naert et al suggested : a rigid manner would overstress the implant and result in greater bone loss around the implant in a tooth-implant connection.
The authors however preference for rigid connection over a non-rigid connection

22. Evaluation of 185 implants in 111 patients followed for 3 years
Lindhe et al reported that marginal bone loss was within the 1 mm limit for the majority of the implants in a tooth –implant connection
Those implants that lost more than 1 mm in the first year, the bone level stabilized at the follow-up visits.
Other authors have reported good treatment results where implants and teeth were rigidly connected together in a fixed prosthesis

23. Summary
Intrusion of teeth in non-rigid connection may be the only negative aspect and this seems to
be resolved through rigid connection.

24. 3.)Malposition or angulation of an implant
There is option to use short or tilted implants that can increase the availiable bone length by 50% when tilted aproximately 30º or” by avoiding anatomical structures
Implant Complications
Mª Angeles Sánchez Garcés, Jaume Escoda-Francolí and Cosme Gay-Escoda
University of Barcelona, Faculty of Dentistry, Spain

25. A wrong planning that involves a malposition or an overangulation, would represent an obstacle for carrying out the prosthetic restoration, while it also would deteriorate long-term

26. In the event that a negligence or bone deficit, an implant placed with an angulation , makes it dysfunctional
it is suggested the use of a repositioning system that has yielded excellent results and which is based on the osteogenic distraction of a bone fragment containing the integrated implant
(Gotta et al., 2008;Mendonca et al.,. 2008; Oduncuoglu et al., 2011).

27. The distraction rate is the usual value (1 mm per day)
All of which improves esthetic effects, as well as the biomechanical behavior of the implant by
correcting crown-root proportion,contour of soft tissues and the relation with neighboring teeth.
The distraction rate is the usual value (1 mm per day)
The consolidation period is 8 weeks, and confirm implant stability in time
(Oduncuoglu et al., 2011).

28. Bruxism

29. Bruxism is a movement disorder of the masticatory system that is expressed by tooth grinding and clenching, during sleep as well as during wakefulness
SB is controlled by the central nervous system, so it is difficult to prevent

30. Sleep bruxism research diagnostic criteria (SB-RDC) by Lavigne et al.
(1) a history of frequent tooth grinding occurring at least 3 nights per week for the preceding 6 months, as confirmed by a sleep partner (2) clinical presence of tooth wear (3) masseter muscle hypertrophy; (4) report of jaw muscle fatigue or tenderness in the morning.

31. The young man has normal teeth. (left frame)
By middle age (middle frame), bruxism flattened this man’s teeth and changed his appearance.
By old age (right frame), the change is even more remarkable (Source: Gelb, 1994, p. 227).

32. Facial appearance of a 13-year-old bruxer with left masseteric hypertrophy (arrow on right). 

33. Signs Symptoms
Occlusal trauma, abnormal occlusal wear surface, abfractions and fractures in the teeth.
Tooth loss and gum recession
Bruxism can be loud enough to wake a sleeping partner. Some individuals clench without significant lateral movements
Anxiety, stress, and tension
Depression
Earache
Eating disorders
Headaches
Migraines
Loose teeth
Tinnitus
Gum recession
Neck pain
Insomnia
Sore or painful jaw
Bruxism: its multiple causes and its effects on dental implants
Frank Lobbezoo – April 25th, 2005

34. Diagnosis
Diagnosis
The most reliable diagnostic technique is measuring EMG (electromyography). These measurements pick up electrical signals from the chewing muscles (masseter and temporalis). This method is commonly used in sleep labs.
Bruxism: its multiple causes and its effects on dental implants
Frank Lobbezoo – April 25th, 2005

35. Bruxism is frequently considered an aetiological factor for temporomandibular disorders (TMDs), tooth wear, loss of periodontal support, and failure of dental restorations

36. Treatment
A dental guard or splint can reduce tooth abrasion. made of plastic and fit over some or all of upper and/or lower teeth. The guard protects the teeth from abrasion and can reduce muscle strain
Biofeedback :The first wearable nighttime EMG biofeedback device (the biofeedback headband)

37. Bruxism and Implant failure
Bruxism is not an absolute contraindication to implant restorations, but caution and careful treatment planning would be essential in such cases
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

38. Bruxism and Implant failure
Due to the absence of a periodontal ligament, the proprioception around dental implants is limited
Consequently the proprioceptive feedback mechanisms to the jaw closing muscles are limited as well
The forces that are applied to implants during bruxism are even larger than during mastication
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

39. Bruxism and Implant failure
The most serious biologic response to overloading is crestal bone loss
The most common restorative complications of overloading are screw loosening, screw fracture, and porcelain fracture
Biological complication
Biomechanical complication
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

40. Bruxism and Implant failure
Biological complication
Early failure : osseointegration was insufficient
Early loading (6-8 wks after surgery)
Immediate loading (within 2 wks following surgery)
Late failure : pathologic bone loss after full osseointegration
Usually localized around the cervix of implant
“Excessive” : the loss is more than 0.2 mm/year, after 1 year functional usage
Associated with overload
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

41. Bruxism and Implant failure
Mechanical load  Bone adaptation and remodeling
Bone resorption = Bone deposition
Equilibrium 
Physiological load
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

42. Bruxism and Implant failure
Biting force is seven to eight times of normal masticatory forces
Bone resorption > Bone deposition
Equilibrium is disturbed 
Overload
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

43. Bruxism and Implant failure
Caused fatigue-related micro-fractures at/around the bone-implant interface
Followed by bone resorption
Repaired by connective tissue and epithelium instead of new bone  radiolucency
Overload
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

44. Bruxism and Implant failure
Bone resorption
The difference between implant and bone elasticity (Titanium is so much stiffer than bone , a stress occurs at the interface of the bone and implant, placing the bone at risk for resorption
Bone is often immature at the time of initial prosthetic loading and susceptible to osteoclastic activity
Overload
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

45. Bruxism and Implant failure
Bone resorption
Implants do not have the PDL that can provide increased proprioception, better distribution of forces, sharper pain perception, or adaptations to overloading, such as thickening of the PDL
Overload
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

46. Bruxism and Implant failure
Biomechanical complications
One or more components of an implant system fail
Fracture of implant
Loosening or fracture of connecting screws or abutment screws
Loosening or excessive wear of mesostructures in overdentures
Excessive wear or fracture of suprastructural porcelain or acrylic teeth
F. Lobbezoo et al. (2006). Review article Dental implants in patients with bruxism habit. Journal of oral rehabilitation. 33;

47. Bruxism and Implant failure
Biomechanical complications
Fracture of implant
Two main causes
Loss of supporting tissue secondary to infection or peri-implantitis
Mechanical problems : metal fatigue due to biomechanical overloading **
Arturo Sánchez-Pérez et al. (2010, may). Etiology, risk factors and management of implant fractures. Med Oral Patol Oral Cir Bucal. 15(3);

48. Bruxism and Implant failure
Biomechanical complications
Fracture of implant
Mechanical problems :
metal fatigue due to
biomechanical overloading **
Signs of metal fatigue :
loosening, torsion or fracture
of the screws, and ceramic
fracture of the prosthesis
Arturo Sánchez-Pérez et al. (2010, may). Etiology, risk factors and management of implant fractures. Med Oral Patol Oral Cir Bucal. 15(3);

49. Bruxism and Implant failure
Biomechanical complications
Screw loosening
Risk factors : prosthesis design or misfit, excessive or off-axis forces from a premature contact or a steep cusp angle
Treatment planning  no premature contact, flatten steep cusp angles, narrow occlusal table, wide diameter implant rather than a narrow diameter implant
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

50. Bruxism and Implant failure
Biomechanical complications
Screw fracture
Excessive shear forces
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

51. Bruxism and Implant failure
Biomechanical complications
3 reasons
1.No PDL for stress release, forces are higher, and fatigue, creep, and permanent deformation are more likely to occur
2.Small base of implants (3 to 6 mm) compared to the wider base of natural teeth (10 to 12 mm) caused the areas of unsupported porcelain that can fracture
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

52. Bruxism and Implant failure
Biomechanical complications
Material fracture
Material selection : Acrylic resins, gold, porcelain, metal
Donald A. Curtis. (2000). Occlusal Considerations for Implant Restorations in the Partially Edentulous Patient. JOURNAL OF THE CALIFORNIA DENTAL ASSOCIATION.

54. Introduction
The most important factor in implant longevity is the formation of a direct interface between the implant and the bone called “osseointegration”.

55. Despite the very high success rates complications may occur.
Early loading failure may affect 2%to 6%of implants
Excess load on a final restoration after successful implant integration can result in failure of the implant

56. Clinical trials regarding the influence of bruxism on implant prostheses are scarce.
Bragger et al. : recognized a relation between bruxism and fracture of the suprastructure, but could not show the relation
Engel et al. : suggested that bruxism never affected the marginal bone loss of the dental implant.

57. It is difficult to conclude that bruxism is a risk factor for dental implants. Since most of the clinical research excluded subjects with bruxism
There are only few research data on the influence of bruxism on dental implant
still no scientific evidence for a relation between bruxism and implant failure.

58. Occlusal Considerations for implant Prostheses
Taylor et al. : mastication is a side-to-side action that does not lend itself to axial loading of teeth or implants, the damaging effects of bruxism are created through lateral friction between the occlusal surfaces

59. Miyata et al. In an animal study investigated
the relationship between occlusal overload and peri-implant tissue and suggested that peri-implant bone resorption occurred under occlusal overload
Heitz-Mayfield et al. a period of 8 months of excessive occlusal load on titanium implants
did not result in loss of osseointegration or marginal bone loss

60. A literature review concluded that the occlusal scheme for an implant prosthesis should be designed to decrease cuspal interferences, centralize forces along the long axis, and minimize lateral forces

61. Since successful long-term results of implant prostheses concluded that the variety of methods related to occlusal morphology used in FPD. on natural teeth are equally acceptable for rehabilitation on dental implants.

62. Important risk factors for dental implants and their suprastructures
Bruxism, other parafunctions
Fractures of natural teeth from occlusal forces
Lateral occlusal contacts on the implant prostheses

63. so far, studies on bruxism and implant failure do not yield consistent results . However, a careful approach was recommended, although these recommendations were “experience based,”

64. Occlusal material for the suprastructure in Implant Prostheses
In the past decades, strongly recommended to use a shock-absorbing material, such as, acrylic resin on top of the suprastructure, to protect the implant-bone interface
Acrylic resin denture teeth were predominantly used during the initial years of dental implant use

65. support for the use of porcelain
In a clinical study on five subjects
using fixed prostheses with either acrylic resin or porcelain occlusal surfaces
masticatory forces were recorded while the subjects chewed various foods.
no differences related to tooth material could be detected in the load rates
In a study covering 6 years, the use of porcelain instead of composite resin had no influence on the marginal bone height around the implants
support for the use of porcelain
as occlusal material

66. In current clinical practice, porcelain has become the primary occlusal material for single-tooth and partial fixed implant prostheses .
Generally agreed that ceramic occlusal surfaces provide superior esthetics and wear resistance .
Regarding full-arch fixed prostheses on implants, metal ceramic prostheses are sometimes presented

67. Porcelain has become the primary occlusal material for single-tooth and partial fixed implant restorations.

68. Although there is no evidence regarding the preferred restorative materials in implant prosthesis for patients with bruxism
some clinicians prefer metal restorations , not porcelain to protect the implant prostheses in patients with bruxism
Especially for second molar teeth in the maxilla

69. Although there is no evidence regarding the preferred restorative materials in implant prosthesis for the patients with bruxism,
some clinicians applied non porcelain but metal restorations to protect the implant prostheses in patients with bruxism, especially for second molar teeth in the maxilla (since there is no esthetic problem).

70. More clinical trials are needed to provide evidence for these recommendations.
More recently, framework or crowns in zirconia was developed in this field.
However, in a clinical trial on fractured dental zirconia implants, Gahlert et al. reported that “the patient with the fracture of the 4mm diameter zirconia implant was adversely affected by strong bruxism”.

71. Recently, some investigators demonstrated zirconia as a new dental implant material .
The development of new dental implant material might change the relationship between fractured dental implants and bruxism.

72. Night Guard and Phamacological Approach for Bruxism
PREVENTION
Night Guard and Phamacological Approach for Bruxism
Parafunctional habits can transmit forces to the supporting bone result in destructive lateral stresses and overloading.
The consequences of parafunctional habits may be prevented by acrylic resin night guards
A night guard contributes to distributing and vertically redirecting forces

73. A night guard promotes even occlusal contacts around the arch in centric-related occlusion can be helpful to prevent fractures of implant prostheses.
If the colored acrylic is not worn through, the parafunction was not excessive

74. The occluding surface of the guard is relieved over the implant prostheses so no occlusal force is transmitted to the implants.
A soft material may also be placed around the crowns for stress relief

75. A night guard may be one of the possible solutions to prevent overloading of the suprastructure of implant prostheses. Soft material also could be used for night guards.

76. Some proposed a pharmacological approach for bruxism patients with implant prostheses , especially in cases where oral implants failed as a consequence of severe sleep bruxism.
The administration of low doses of the dopamine D1/D2 receptor agonist pergolide
Botulinum toxin (Botox) can lessen bruxism's effects. An extremely dilute form of Botox is injected to weaken (partially paralyze) muscles to 'relax' the muscles of the face.

77. Conclusion Conclusion
Only little research has focused upon the clinical approach to protect implant prostheses from bruxism.
The presented results may need modification when new research results or new dental implant materials appear.
At present, expert opinion and cautionary approaches are still considered the best available sources for suggesting good practice indicators.

78. Thank you for your attention