PART 2 Preoperative Assessment and Treatment Planning 26/11/2015 - - PDF document

1/6/2016 1

PART 2 Preoperative Assessment and Treatment Planning

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

55

Preoperative Assessment and Treatment Planning

• How many teeth are missing?
• What is the degree of bone loss?
• Are the remaining teeth in a good position and do

they have a long-term prognosis?

• What does the patient expect for an end result?
• What treatment will result in the best cosmetic
• utcome?
• What is the patient's budget?

1/6/2016 2

Preoperative Assessment and Treatment Planning

• Chief Complaint:

– The goal of the clinician is to explore, conversationally, the details of the patient’s concerns, desire for treatment, apprehensions, and goals for the desired outcome. – The clinician must assess how realistic the patient’s expectations are. Is the patient looking strictly for a functional replacement, or is there a strong esthetic expectation? – How does the patient’s expectation fit his or her perceived timeline or financial investment?

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

57

Preoperative Assessment and Treatment Planning

• The evaluation of a patient as a suitable candidate

for implants should follow the same basic format as the standard patient evaluation, although some areas require additional emphasis and attention: I. Medical History. II. Psychological Status. III. Dental History.

1/6/2016 3

• I. Medical History
• The patient’s medical history may reveal a number
• f conditions that could complicate or even contra-

indicate implant therapy. These include:

1. Bleeding disorders; Paget’s disease; A history

• f

radiation therapy in the maxilla or mandible region; Uncontrolled diabetes; Epilepsy that presents with more than one grand mal seizure per month; 2. In addition, there are a host of systemic medical conditions, including steroid therapy, hyperthyroidism, and adrenal gland dysfunction 3. Substance abuse including tobacco and alcohol

• II. Psychological Status
• If the patient cannot come to terms with the

possibility

• f

failure,

• r

months

• f

potential discomfort and inconvenience, then he or she is not a suitable candidate for implant therapy.

1/6/2016 4

• III. Dental History
• It is also vital to evaluate the patient’s chief complaint, as it

may have an equal bearing on treatment. For example, the treatment plan recommended to the patient desiring a more secure lower denture will be quite different from the one proposed to the patient seeking a fixed and rigid appliance.

Clinical examination

I. Extraoral examination:

• 1. Facial form.
• 2. Facial symmetry.
• 3. Patient’s degree of expression and animation.
• 4. Patient appearance (e.g., facial features, facial hair,

complexion, eye color).

• 5. Smile line.
• 6. Incisal edge or tooth display.
• 7. Buccal corridor display.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

62

1/6/2016 5

Clinical examination

II. Intraoral examination:

• 1. Condition of existing teeth.
• 2. Pathologic conditions in any of the hard or soft tissues.

All oral lesions, especially infections, should be diagnosed and appropriately treated before implant therapy.

• 3. Patient’s habits.
• 4. Level of oral hygiene, overall dental and periodontal

health.

• 5. Occlusion, jaw relationship, temporomandibular joint

condition, and ability to open wide.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

63

Clinical examination

• III. Evaluation of the edentulous space or ridge:

a. Evaluation of ptential implant sites. All sites should be clinically evaluated to measure the available space in the bone for the placement of implants and in the dental space for prosthetic tooth replacement. b. The height, width, and contour of the edentulous ridge is visually assessed and carefully palpated. c. The presence of concavities/depressions (especially on the labial aspects) is usually readily detected. d. The thickness of the soft tissue can be measured by puncturing the soft tissue with a calibrated probe after administering local anesthetic or carrying out a more detailed ridge mapping.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

64

1/6/2016 6

Clinical examination

• Ridge mapping (bone sounding):

– Ridge mapping is advocated by some clinicians. – In this technique, the area under investigation is given local anesthesia and the thickness of the soft tissue measured by puncturing it to the bone using either a graduated periodontal probe or specially designed calipers. – The information is transferred to a cast of the jaw, which is sectioned through the ridge. This method gives a better indication ofbone profile than simple palpation.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

65

Clinical examination

• d. The

profile/angulation

• f

the ridge and its relationship to the

• pposing

dentition is also important. e. The distance between the edentulous ridge and the

• pposing dentition should be measured to ensure

that there is adequate room for the prosthodontic components. f. Assessment of the soft tissue thickness, which is important for the attainment of good aesthetics. Keratinized tissue, which is attached to the edentulous ridge, will also generally provide a better peri-implant soft tissue than nonkeratinized mobile mucosa.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

66

1/6/2016 7

Clinical examination

A patient with missing maxillary anterior teeth in whom the lower incisors nearly touch the soft tissue ridge in centric

• cclusion.

Extensive loss of mandibular bone with marked vertical and horizontal discrepancy between the jaws

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

67

Radiographic examination

• Methods of radiographic

examination:

1. Periapicals. 2. Occlusal. 3. OPG. 4. Cephalometric. 5. CBCT. 6. CT.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

68

1/6/2016 8

Radiographic examination (CBCT)

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

69

Radiographic examination

Advantages and Disadvantages of the Various Radiographic Projections

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

70

1/6/2016 9

Radiographic examination

• Areas of study radiographically include the

following:

• 1. Location of vital structures:

– Mandibular canal. – Anterior loop of the mandibular canal – Mental foramen. – Maxillary sinus. – Nasal cavity. – Incisive foramen.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

71

Radiographic examination

• 2. Bone height.
• 3. Root proximity and angulation of existing teeth.
• 4. Evaluation of cortical bone.
• 5. Bone density and trabeculation.
• 6. Pathology (e.g., abscess, cyst, tumor).
• 7. Cross-sectional topography, bone width and

angulation (best determined by using CT and CBCT).

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

72

1/6/2016 10

Radiographic examination

• Critical

measurements specific to implant placement include the following:

a. At least 1 mm inferior to the floor of the maxillary sinus and nasal cavity.

• b. Incisive canal (maxillary midline implant placement)

to be avoided. c. 5 mm anterior to the mental foramen.

• d. 2 mm superior to the mandibular canal.

e. 3 mm from adjacent implants. f. 1-1.5 mm from roots of adjacent teeth.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

73

Radiographic examination

• Radiographic stent - (can double as surgical stent)

acrylic stent with lead beads or ball -bearings (5mm) placed in proposed fixture locations allows more accurate radiographic interpretation also to provide calibration for potential magnification.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

74

1/6/2016 11

Diagnostic casts and photographs

• Mounted study models as well

as intraoral and extraoral photographs complete the records collection process.

• Study models mounted on a

semi-adjustable articulator using a face-bow transfer give the clinician a three-dimensional working representation of the patient and provide much information required for surgical and prosthetic treatment planning.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

75

Diagnostic casts and photographs

• Elements that can be evaluated from accurately

mounted models include the following:

1. Occlusal and arch relationships. 2. Interarchspace. 3. Arch form, anatomy, and symmetry. 4. Pre-existing occlusal scheme. 5. Curve of Wilson and Curve of Spee. 6. Number and position of the existing natural teeth. 7. Tooth morphology. 8. Wear facets 9. Edentulous ridge relationships to adjacent teeth and opposing arches.

• 10. Measurements for planning future implant locations.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

76

1/6/2016 12

Basic treatment order

• A traditional treatment plan may include the

following:

1. Examination—clinical and radiographic. 2. Diagnostic setup, provisional restoration, and specialized radiographs if required. 3. Discussion of treatment options with the patient and decision on final restoration. 4. Completion of any necessary dental treatment including: a. Extraction of hopeless teeth. b. Periodontal treatment. c. Restorative treatment, new restorations and/or endodontics as required.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

77

Basic treatment order

5. Construction

• f

provisional

• r

transitional restorations if required. 6. Construction of surgical guide or stent. 7. Surgical placement of implants. 8. Allow adequate time for healing/osseointegration according to protocol, bone quality, and functional demands. 9. Prosthodontic phase

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

78

1/6/2016 13

Planning for single tooth replacement

• Examination

1. lips and the amount of tooth or gingiva that is exposed when the patient smiles. A high smile line exposing a lot

• f gingiva is the most demanding aesthetically with both

conventional and implant prosthodontics. 2. The height and width of the edentulous ridge. 3. Measurement of the tooth space at the level of the crown, at the soft tissue margin. 4. The available width at the root level determines whether an implant and abutment can be accommodated without compromising the adjacent tooth roots and soft tissue. A commonly quoted minimal dimension is 6 mm.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

79

Planning for single tooth replacement

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

80

1/6/2016 14

Planning for single tooth replacement

• Examination of the Occlusion

– The adjacent tooth contacts (and that of the preexisting prosthetic replacement if available) should be examined in centric occlusion, retruded contact, and protrusive and lateral excursions. Occlusal contacts on the single tooth implant restoration should be designed such that contacts

• ccur first on adjacent teeth.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

81

Planning for implant supported fixed bridge

• Examination

– The degree of ridge resorption is evaluated. the degree of resorption would compromise implant placement and aesthetics because of a high lip line or insufficient lip support. These factors should be further assessed using diagnostic waxups and diagnostic removable prostheses. – The vertical height and occlusal relationship in centric jaw relationship and protrusive and lateral excursions should be examined and recorded. – Important notes:

1. In severely resorbed cases, a fixed bridge prosthesis will almost certainly require the addition of prosthetic gingivae. 2. The restoration height is more likely to be unfavorable. 3. Resorption of the ridge produces a smaller arc of bone to support the implants than that existed to support the teeth

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

82

1/6/2016 15

Planning for implant supported fixed bridge

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

83

(A) Patient with an upper complete denture with lips at rest showing good lip support. (B) Removal of the denture and inparticular the flange results in collapse of the upper lip and giving the presentation of a pseudo class 3 jaw relationship. (C) The degree of ridge resorption

Planning for implant supported fixed bridge

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

84

• Anterior tooth loss where the existing denture had a large labial flange to provide lip

support (left).

• Diagnostic denture without the flange can help the clinician and patient visualize the end

result intraorally and assess the lip support (center).

• The slight loss of lip support with a gum-fitted setup (right) was acceptable to the patient to

achieve an eventual fixed result (right).

1/6/2016 16

Planning for implant supported fixed bridge

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

85

Planning for implant supported fixed bridge

• Planning implant number and distribution for implant supported fixed

bridge work.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

86

Examples of types of replacement required Suggested number of implants and prosthetic solution Full-arch bridges in edentulous maxilla At least five or six implants—preferably extending to second premolar region. Full-arch bridges in edentulous mandible At least four or five implants in the region between the mental foramina. Missing molars Two missing molars normally require three standard- diameter implants. Two wide-diameter implants could be used to support a bridge Three missing maxillary anterior teeth Two or three implants supporting a bridge If there is sufficient space for three implants. Four missing maxillary anterior teeth Four upper incisors would require two implants to support a bridge. Four missing mandibular incisors Four lower incisors could be replaced using two implants and a fixed bridge. The same solution may be adequate to replace mandibular canines and incisors (which is not the case in the maxilla)

1/6/2016 17

Planning for implant supported fixed bridge

A) CBCT, 3D implant manipulation as well as a realization of the abutment and restorative spaces. Nerve tissue can be highlighted within the jaw using a transparency tool. (B) The software program can also depict bone density levels around the implant as measured by Hounsfield units.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

87

Planning for implant supported fixed bridge

• Implant supported fixed bridge or multiple single units?

– There is a trend to place an implant for each individual missing tooth, but there are a number of potential problems with this approach:

1. Some teeth, such as lower incisors, have a small mesiodistal dimension that is less than most implants. 2. Teeth can function perfectly well with very small amounts of intervening hard and soft tissue (less than 1 mm), unlike implants. 3. As teeth are lost and the jaws resorb, the perimeter of the arch decreases, thus reducing the space for implant placement. 4. The angulation of natural roots in the healthy alveolus may be impossible to mimic in the resorbed jaw. Proclination of natural anterior teeth and anatomical variations such as crown/root angulations are difficult to mimic with implants.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

88

1/6/2016 18

Planning for implant supported fixed bridge

• 5. Tapering of normal root forms may allow more

teeth within a given area of jaw bone.

• 6. Failure of a single implant in a multiple single-unit

case requires replacement of that unit. The fixed bridge solution may still be workable with one implant less.

• 7. Provision of a fixed bridge with fewer implants

than the teeth that are being replaced is more economical/cost effective.

• 8. The splinting afforded by the fixed bridge may

improve the biomechanical properties.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

89

Planning for implant supported fixed bridge

• The potential advantages of multiple single units are

as follows:

• 1. More natural appearance.
• 2. No need for complex casting to precisely fit multiple

abutments.

• 3. Simpler prosthodontic procedures.
• 4. Patient can floss between units.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

90

1/6/2016 19

Planning for implant supported fixed bridge

Provisional restoration: 1. Removable Dentures – The most simple provisional prosthesis is a complete or partial removable denture. When constructed in acrylic, they provide an inexpensive and readily adjustable prosthesis that can be modified to produce a radiographic stent or duplicated and modified to produce a surgicalstent. 2. Essix Splint – With small spans, consideration can be given to an Essix splint modified by the incorporation of artificial teeth as an alternative to a partial denture. This also has the benefit of avoiding transmucosal loading.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

91

Planning for implant supported fixed bridge

3. Fixed Bridgework

– Provisional fixed bridgework may be the treatment of choice, particularly for patients having extensive treatment who are not prepared to undergo a period

• f

time without a fixed restoration. – Transitional mini implants (very narrow diameter implants) placed between the definitive implants can be considered as provisional bridge supports and removed before the final prostheses is constructed. – Fixed provisional bridgework enables ridge augmentation procedures to be carried

• ut

without the risk

• f

transmucosal loading and the associated micromovement affecting the healing, and should reduce complications.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

92

1/6/2016 20

Treatment planning for implant

• verdentures
• Indications of implant overdentures:

1. Where complete dentures have been worn successfully for many years but severe resorption, or loss of neuromuscular control, now limits retention or stability causing movement

• f one or both dentures.

2. Where a fixed restoration cannot provide sufficient replacement of resorbed hard and soft tissues to produce an acceptable appearance. 3. Where remaining natural teeth have an unfavorable distribution for retention and support of a removable partial denture. 4. Where patients have had head or neck surgery that results in an alveolar defect/compromised anatomy.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

93

Treatment planning for implant

• verdentures

A resorbed mandibular ridge. The patient has a reduced denture bearing area, resulting in poor support for a conventional denture. Maxillary ridge with extensive resorption in the tuberosity region

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

94

1/6/2016 21

Treatment planning for implant

• verdentures

Partially dentate patient with unilateral loss of

• teeth. Four implants were placed in the anterior

region and a cast bar constructed to support and retain a partial overdenture Trial setup. This can be used to assess not only tooth position, shade, and size but also soft tissue support.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

95

Treatment planning for implant

• verdentures
• Diagnosis and treatment planning:

– Once treatment has been decided, the next step is to plan the sequence of the stages. – Unless the existing dentures are technically correct, a trial setup is essential to decide proposed tooth position. – Once tooth position is confirmed, a stent can be made from the trial denture or duplicate of the existing denture. – Guide holes are then cut in the stent to indicate proposed implant position.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

96

1/6/2016 22

Treatment planning for implant

• verdentures

Surgical guide Duplicate denture

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

97

Treatment planning for implant

• verdentures
• Prosthetic components for implant overdentures:

1. Astra Tech (Sweden):

• This manufacturer supplies a ready made 1.9-mm-diameter

round gold alloy bar, 50 mm in length, The bar is soldered to gold alloy cylinders, which are screwed to uniAbutments or custom made bar in which CAD/CAM technique can be used.

• A metal housing (e.g. Clips) is cured into the denture and

plastic inserts can be put inside the housing to activate the retention.

• Also there is a 2.25-mm-diameter ball attachment (ball and

socket), Retention can be achieved either with an adjustable four-tine gold alloy matrix that is processed into the acrylic resin of the denture or the Clix system.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

98

1/6/2016 23

Treatment planning for implant

• verdentures

Milled bar. Custom made utilizing CAD/CAM technology notice the lack of welding seams

• r visible porosities.

3D scan. The wax try-in is scanned and CAD software is used to design the bar within the confine of try-in and related to the position

• f the implants.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

99

Treatment planning for implant

• verdentures

Astra Tech uniAbutment. Made of commercially pure titanium. Astra Tech ball attachment

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

100

1/6/2016 24

Treatment planning for implant

• verdentures

Gold cap Astra. Four-tine gold alloy matrix Clix system

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

101

Treatment planning for implant

• verdentures

Clip Gold bar

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

102

1/6/2016 25

Treatment planning for implant

• verdentures

2. Nobel Biocare (Switzerland): – This manufacturer offers various bars and ball attachments for implant dentures. The original 2mm diameter round bar and small clip system has been expanded to include Dolder. – These preformed gold bars can be soldered to gold cylinders, which are screwed to multiunit abutments or fixture head. – Nobel Biocare now also supports a CAD/CAM titanium milled bar. 3. Straumann (Switzerland): – This manufacturer supplies mini and regular egg-shaped gold alloy Dolder bars and clips and U-shaped Dolder bars.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

103

Treatment planning for implant

• verdentures

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

104

Dolder: Egg shaped bar

1/6/2016 26

Treatment planning for implant

• verdentures

Dolder bar clip processed into a maxillary

• verdenturewith the palate cutout.

The cross-section shows the fit of the ball within the attachment in the denture.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

105

Treatment planning for implant

• verdentures
• Mandibular overdenture:

– Two to four implants placed between the mental foramina have been suggested with the denture being retained by clips onto a bar joining the implants, by ball attachments onto the individual implants, or by

• magnets. Bars have been round or ovoid to allow some rotation of the

denture. – The results from medium and long-term studies, have shown that two implants placed in the canine region are sufficient to stabilize a mandibular denture.

• Maxillary overdenture:

– The minimum number of implants in the maxilla for an

• verdenture is four, there seems to be evidence that they do

not necessarily have to be splinted with a bar.

26/11/2015 LIMU

• Dr. Rafik M. Alkowafi

106