Implants

Clinical aspect and evaluation of the implant patient:-

DR. ROOBAL BEHAL

(CONSULTANT)

DR. MEHRAJ KIRMANI

DR. FAYIZA YAQOOB KHAN

(REGISTRARS)

• W. R. Laney who served for a long time as the Editor in

Chief of the International Journal of Oral and Maxillofacial

Implants (JOMI), an implant is defined as “an artificial

material or tissue that shows biocompatibility upon its

surgical implantation”.

• TYPES & CLASSIFICATIONS OF DENTAL

IMPLANTS

– FIVE CLASSIFICATIONS

1. Based on implant design.

2. Based on attachment mechanism.

3. Based on macroscopic body design.

4. Based on the surface of implant.

5. Based on the type of material

• COMPONENTS OF DENTAL IMPLANT

• Clinical aspect and evaluation of

the implant patient:-

• Clinical aspect and evaluation of the implant patient:-

• The main aim of dental implant therapy is to satisfy the patient's desire to

replace one or more missing teeth in an • esthetic,

• secure,

• functional,

• and long-lasting manner.

• To achieve this , clinicians must accurately diagnose

– current dentoalveolar condition,

– overall mental and physical well-being of the patient.

– Local evaluation of potential jaw sites for implant placement (e.g.,

measuring available alveolar bone height, width, and jaw relationship)

and prosthetic restorability

• However, determine whether the patient is a good candidate for implants

• includes identifying factors that might increase the risk of failure or

complications,

• determining whether the patient's expectations are reasonable.

• Clinical aspect and evaluation of the implant patient:-

– pretreatment evaluation of potential implant patients

– possible risk factors and contraindications.

– posttreatment evaluation of patients with implants.

– implant maintenance.

• pretreatment evaluation of potential implant patients

• Case types and indications of implants:-

• Edentulous patient:-

• most benefited from dental implants are fully edentulous arches. These

patients can be effectively restored, both esthetically and functionally, with

an implant-assisted removable prosthesis or an implant-supported fixed

prosthesis.

• Original design for complete edentulous patients was a fixed-bone–

anchored bridge that used five to six implants in the anterior area of the

mandible or the maxilla to support a fixed, hybrid prosthesis.

The design is a denture-like complete arch of teeth attached

to a substructure (metal framework), which in turn is

attached to the implants with cylindrical titanium abutments.

The prosthesis is fabricated without flange extensions and

does not rely on any soft tissue support. It is entirely

implant supported

Usually, the prosthesis includes bilateral distal cantilevers,

which extend to replace posterior teeth (back to premolars

or first molars).

• Another design used to restore an edentulous arch is the

ceramic-metal fixed bridge .

• Patients prefer this because the ceramic restoration emerges

directly from the gingival tissues in a manner similar to the

appearance of natural teeth.

– One limitation of both hybrid and ceramometal implant-

supported fixed prostheses is that they provide very little lip

support and thus may not be indicated for patients who have

lost significant alveolar dimension. This is often more

problematic for maxillary reconstructions patients.

– some patients, there is lack of a complete seal (i.e., spaces

under the framework) allows air to escape during speech, thus

creating phonetic problems.

• Depending on the

– volume of existing bone,

– jaw relationship,

– lip support, and phonetics,

• patients may not be able to be rehabilitated with an implant-

supported fixed prosthesis.

• For them a removable, complete-denture type of prosthesis is a

better choice because

– provides a flange extension that can be adjusted and contoured

to support the lip,

– there are no spaces for unwanted air escape during speech.

• This type of prosthesis can be retained and stabilized by two or

more implants placed in the anterior region of the maxilla or

mandible.

• the stability of the implant-retained overdenture is not same as

rigidly attached, implant-supported fixed prosthesis,

• But there is increased retention and stability over conventional

complete dentures is an important advantage for denture wearers

(Zitzmann 1999)

• protect alveolar bone from additional bone loss caused by long-

term use of removable prostheses that are bearing directly on the

alveolar ridges.

• Partially Edentulous Patients:-

• Multiple missing teeth

• Partially edentulous patients present another viable treatment option for

osseointegrated implants, but the remaining natural dentition (occlusal

periodontal health status, relationships, and esthetics) introduces additional

challenges for successful rehabilitation (Van Steenberghe et al. Int J Oral

Maxillofac Implants 1994)

– endosseous dental implants and its close proximity requires special attention

and planning (Belser UC et al Periodontol 2000 1998)

• major advantage of implant-supported restorations in partially

edentulous patients is.

– they replace missing teeth without invasion, alteration or

preparation of natural teeth

– larger edentulous spans (Kennedy Class I and II) can be restored

with implant-supported fixed bridges ( Key MC, et al Int J Oral

Maxillofac Implants 1992)

• Difficulty:-

• use of endosseous implants to replace missing teeth in the partially

edentulous patient were a challenge

underestimation of the importance of treatment planning for implant-retained

restorations with an adequate number of implants to withstand occlusal loads.

two implants could be used to support a multiunit fixed bridge in the posterior

area; complications or failures (mechanical or biologic)

• The use of stronger implants and better treatment planning (more

implants used to support more restorative units), particularly in areas

of poor-quality bone, has solved many of these problems.

• Single Tooth:-

• Patients with a missing single tooth (anterior or posterior) benefits greatly

from the success and predictability of endosseous dental implants.

• Replacement of a single missing tooth with an implant-supported crown is a

much more conservative approach than preparing two adjacent teeth for the

fabrication of a tooth-supported fixed partial denture

• success rates for single-tooth implants are excellent.[Hirsch JM J

Oral Sci 1998 ]

• Replacement of an individual missing posterior tooth with an

implant-supported restoration has been successful as well.

– greatest challenges to overcome with the single-tooth implant restorations

were screw loosening and implant or component fracture.

– Because of increased potential to generate forces in the posterior area, the

implants, components, and screws often failed.

• Esthetic Considerations:-

• Some cases are more esthetically challenging

• because of the nature of each individual's smile and display of teeth.

• The prominence and occlusal relationship of existing teeth,

• the patient's own psychologic perception of esthetics.

• Cases with good bone volume, bone height, and tissue thickness can be

predictable in terms of esthetic results.

• However patients with less-than-ideal tissue qualities poses difficult

challenges for the restorative and surgical team.[Belser UC Periodontol

2000 1998 ]

• patient with a high smile line, compromised or thin periodontium, inadequate

hard or soft tissues,

• and high expectations,

Pretreatment Evaluation:-

comprehensive evaluation is needed for any patient ,considered for

dental implant therapy.

current health status, including a review the patient's past medical

history, medications, and medical treatments.

parafunctional habits, such as clenching or grinding teeth.

any substance use or abuse, including tobacco, alcohol, and

drugs.

The assessment also include an evaluation of the patient's motivations,

level of understanding, compliance, and overall behavior.

Well organized, systematic history and examination is essential to obtaining an

accurate diagnosis and treatment plan

treatment plan should be comprehensive and provide several treatment options

for the patient, including periodontal and restorative therapies.

Information gathered throughout the process will help the clinician's decision

making and determination of whether a patient is a good candidate for dental

implants.

can also reveal deficiencies and indicate what additional surgical procedures

may be necessary for therapy (e.g., localized ridge augmentation, sinus bone

augmentation).

• Chief Complaint:-

• What is the problem or concern in the patient's own words?

• What is the patient's goal of treatment, and how realistic are the

patient's expectations?

• The patient will measure implant success according to personal

criteria.

– overall comfort

– function of the implant restoration ,

– satisfaction with the appearance of the final restoration.

• Patients will evaluate, whether the treatment helped him to eat better,

look better, or feel better.

• Medical History:-

• Medical history is required for any patient in need of dental treatment,

regardless of whether implants are part of the plan (Hollender et al 2003).

• should be documented in writing on history form and verbally through an

interview with the treating clinician.

• Patients must be in reasonably good health to undergo surgical therapy for the

placement of dental implants.

Any disorder that impair the normal wound-healing process, especially when it

relates to bone metabolism,

physical examination is needed if questions arise about the health status of the patient (Branemark

1985).

laboratory tests (e.g., coagulation tests who are receiving anticoagulant therapy).

If any questions remain about the patient's health status, a medical clearance for

surgery should be obtained from the patient's treating physician ( Marx et al 2005

).

• Dental History:-

• patient's past dental experiences are valuable part of the overall

evaluation.

– recurrent or frequent abscesses, which may indicate a susceptibility to

infections or diabetes?

– Does the patient have many restorations?

– How compliant has the patient been with previous dental

recommendations?

– What are the patient's current oral hygiene practices?

– previous experiences with surgery and prosthetics.

• If patient has various problems and difficulties with past

dental care, including dissatisfaction, the patient may have

similar difficulties with implant therapy.

• It is essential to identify past problems and to elucidate any

contributing factors.

• The clinician must also assess the .

– patient's dental knowledge and

– understanding of the proposed treatment,

– patient's attitude and motivation toward implants.

• Local examination:-

• Intraoral examination:-

• performed to assess the current health and condition of oral hard

and soft tissues.

Any pathologic conditions

Any oral lesions, especially infections:-should be diagnosed and

appropriately treated before implant therapy.

Additional criterias include;

the patient's habits,

level of oral hygiene,

overall dental and periodontal health,

occlusion,

jaw relationship,

temporomandibular joint condition,

ability to open wide mouth;

• After intraoral examination, the clinician should evaluate potential

implant sites.

– measure available space in the bone for the placement of implants and

in the dental space for prosthetic tooth replacement

– The mesial-distal and buccal-lingual dimensions of edentulous spaces

can be approximated with a periodontal probe or other measuring

instrument.

• The orientation or tilt of adjacent teeth and their roots should

be noted as well.

– There may be enough space in the coronal area for the restoration

but not enough space in the apical region for the implant if roots

are directed into the area of interest

– there may be adequate space between roots, but the coronal

aspects of the teeth may be too close for emergence and

restoration of the implant.

Ultimately, edentulous areas need to be precisely

measured using diagnostic study models and imaging

techniques to determine whether space is available and

whether adequate bone volume exists to replace missing

teeth with implants and implant restorations.

• Alveolar Bone:-

Before 1981; implant 4 mm in diameter and 10 mm long were used ; the minimal

width of the jawbone needs to be 6 to 7 mm, and the minimal height should be 10

mm (minimum of 12 mm in the posterior mandible, where an additional margin of

safety is required over the mandibular nerve.

The Branemark screw type implant body and osseointegrated approach was

provided only in 3.75mm width and 9mm length.

• Interocclusal Space:-

• The restoration consists of the abutment, the abutment screw, and the crown (

also include a screw to secure the crown to the abutment if it is not cemented).

• Restorative “stack” is the total of all the components used to attach the crown to

the implant.

• The dimensions of the restorative stack vary slightly depending on the type of

abutment and the implant-restorative interface (i.e., internal or external

connection).

• The minimum amount of interocclusal space required for the restorative “stack”

of implant is 7 mm.

7mm

• Diagnostic Study Models:-

• Mounted study models are an excellent means of assessing potential

sites for dental implants.

• Properly articulated models with diagnostic wax-up of the proposed

restorations allow the clinician to evaluate the available space and

to determine potential limitations of the planned treatment.

• This is particularly useful when multiple teeth are to be replaced

with implants or when a malocclusion is present.

• Hard Tissue Evaluation:-

• The amount of available bone is the next criterion to evaluate.

• Wide variations in jaw anatomy ; it is therefore important to analyze the

anatomy of the dentoalveolar region of interest both clinically and

radiographically.

• A visual examination can immediately identify deficient areas ,

• Clinical examination of the jawbone consists of palpation to feel for

anatomic defects and variations in the jaw anatomy, such as concavities

and undercuts.

• Some areas that appear to have good ridge width

require further evaluation

• If desired, it is possible with local anesthesia to

probe through the soft tissue (intraoral bone

mapping) to assess the thickness of the soft tissues

and measure the bone dimensions at the proposed

surgical site.

• Classification System for Available Bone:-

• In 1985, Misch and Judy classified available bone with

treatment options for each category. The basic four divisions

have been further expanded to following categories:-

– Division A

– Division Bi) Division B +

ii) Division B - w (width)

– Division Ci) Division C - w (width)

ii) Division C - h (height)

iii) Division C - a (angulation)

– Division D

• Division A (Abundant Bone)

• This category of bone volume is available soon after tooth loss and is abundant in all

dimensions.

• Division A bone is mainly observed in the anterior regions

• Based on the available dimensions, use of Division A root-form implants with height

> 12 mm and width > 4 mm. Their advantages include:

– Greatest surface area

– Improved stress distribution

– Greatest range of prosthetic options

– Less fracture of implant and components

– Less abutment screw loosening

• Division B (Adequate Bone)

• Slight to moderate atrophy characterized by reduced bone width in

comparison to Division A bone and is mostly observed in the posterior

regions.

• Two subtypes (B + and B - w) exist depending on the extent of

resorption

A Division B ridge

converted to Division A

by osteoplasty

Placement Division B implantRidge augmentation

• Division C (Compromised Bone):-

• Moderate to advanced atrophy; bone may be deficient in one or more

dimensions.

• With continued resorption, the Division C - w bone changes to a

Division C - h bone which is commonly observed in the posterior

regions because the maxillary sinus or mandibular canal limits the

vertical height .

• Division C - a bone is found most often in the anterior maxilla and

mandible with facial undercut regions, or the mandibular second

molar with a severe lingual undercut.

• Treatment Options for Division C Bone

• A) Division C - w

• 1) Osteoplasty

• This converts the Division C - w bone to a Div C - h category The treatment protocol of

Division C - h bone is then followed.

• 2) Augmentation

• Augmentation of Division C - w preferred in the posterior maxilla or mandible.

• B) Division C - h

• 1) Augmentation

• This is advocated in the posterior maxilla and mandible.

• 2) Root-form implants

• Additional implants are required to increase the overall implant-bone surface area to

counteract the unfavorable force multiplier of increases crown height. For the same

reason RP-5 prosthesis is considered to reduce the cantilever action.

• C) Division C - a

• 1) Augmentation to improve the angulation

• 2) Subperiosteal implants

• Division D (Deficient Bone)

• Severe atrophy; is the most difficult to treat.

• Fixed restorations are almost always contraindicated due to

significant crown height.

• Idiopathic fractures during surgery or implant failure or

removal are likely complications.

•

• Treatment Options for Division D Bone

• Augmentation

– Autogenous bone grafts are indicated to upgrade the

division.

– Endosteal or subperiosteal implants may be inserted

depending on the division of bone attained.

• Bone classification based on density:-

• Linkow in 1970, classified bone density inn to three categories

– Class I bone structure:- ideal bone type consists of evenly spaced

trabeculae with small cancellated spaces.

– Class II bone structure:- slightly larger cancellated spaces with less

uniformity of osseous pattern.

– Class III bone structure:- large marrow filled spaces exist between

bone trabeculae.

• 1985, lekholm and Zarb classification based on quality in the anterior

region:-

– Quality I:- composed of homogeneous compact bone.

– Quality 2:- thick layer of compact bone surrounding a core of dense

trabecular bone.

– Quality 3:- thin layer of compact bone surrounding a core of dense

trabecular bone.

– Quality 4:- thin layer of compact bone surrounding a core of low density

trabecular bone.

– Jaffin and Berman reported 10% difference in implant survival

between Quality I and quality 2 and 22% lower survival in quality

4 type of bone

• 1988 Misch classification on bone density:-

• He classified it in to 4 groups independent of region of the jaw, based on

microscopic structure of bone.

D5 Immature, nonmineralized bone

• Anatomic location of bone density types ( % of occurrence)

• Radiographic Examination:-

• Assessment of the quantity, quality, and location of available alveolar bone in

implant site to determine whether a patient is a candidate for implants or

implant site needs bone augmentation.

• Radiographic procedures,

• Standard projections

– Periapical radiographs,

– panoramic projections,

– Occlusal radiographs

– Lateral cephalometric radiographs

• Cross- sectional imaging:-

– Conventional x-ray tomographic

– Computed tomography;

– Cone Beam Computed tomography

– Dual Energy X-Ray Absorptiometry (DEXA)

Imaging helps to identify vital structures such as the floor of the

nasal cavity, maxillary sinus, mandibular canal, and mental

foramen.

In addition it gives absolute dimensional measurement of the

alveolar bone,

it also determines whether the volume of bone radiographically

(as well as clinically) is located in a position to allow for the

proper position of the implant.

The best way to evaluate the relationship of available bone to the

dentition is to image the patient with a diagnostically accurate

guide using radiopaque markers that accurately represent the

proposed prosthetic contours

• Soft Tissue Evaluation:-

• Evaluation of the quality, quantity, and location of soft tissue present in the

implant site helps to know the type of tissue that will surround the implant(s)

after treatment is completed (keratinized versus nonkeratinized mucosa).

• In some cases, depending on the clinician's view of keratinized tissue, may need

soft tissue augmentation.

– Keratinized mucosa is thicker and denser than alveolar mucosa (nonkeratinized).

– forms a strong seal around the implant with a cuff of circular (parallel) fibers

around the implant, abutment, or restoration that is resistant to retracting with

mastication forces and oral hygiene procedures.

– Implants with coated surfaces (i.e., hydroxyapatite [H] or titanium plasma spray

[TPS] coating) demonstrate greater periimplant bone loss and failures in the

absence of keratinized mucosa.(Beckler 1996)

• Additionally, any mucogingival concerns, such as frenum attachments or pulls,

should be thoroughly evaluated.

• Risk Factors and Contraindications:-

• In this era of high implant success and predictability and

complacency, it is imperative for clinicians to recognize risk factors

and contraindications to implant therapy so that problems can be

minimized and patients can be accurately informed about risks.

• the clinician must be knowledgeable in this area and inform patients

about risk factors and contraindications before initiating treatment.

• Some conditions are probably best described as “risk factors”

rather than “contraindications” to treatment because implants can

be successful in almost all patients;

• Ultimately, it is the clinician's responsibility to make decisions as to

when implant therapy is not indicated.

• Medical and Systemic Health–Related Issues:-

• The clinician must see the medical and health-related conditions that affect

bone metabolism or any aspect of the patient's capacity to heal

normally(Beikler T 2003)

• Includes conditions such as

– diabetes,

– osteoporosis, and

– immune compromise, medications, and

– medical treatments such as chemotherapy and irradiation.

• Diabetes :-

• Diabetes is a metabolic disease that can have significant effects on the patient's

ability to heal normally and resist infections ,particularly patients when not well

controlled.

• Poorly controlled diabetics often have impaired wound healing and a

predisposition to infections,

• whereas diabetic patients whose disease is well controlled experience few, if any,

problems.

• Several studies have reported moderate failure rates in diabetic patients, with

implant success ranging from 85.6% to 94.3%.(Balshi TJ 1999).

• A prospective study demonstrated 2.2% early failures and 7.3% late failures in

diabetic patients.(Shernoff AF 1994)

•

• After 5 years, the overall success rate for this group of

diabetic patients was 90% (Olson JW 2000)

• Diabetic patients experience slightly more late failures,

related to less tissue integrity caused by reduced tissue

turnover and impaired tissue perfusion.

• These results suggest that diabetes may be a risk factor for

implants, particularly for late failures. However, the risk does

not appear to be high.

• Bone Metabolic Disease

• Osteoporosis is a skeletal condition characterized by decreased

mineral density.

• classifications are

– primary (three types)

– secondary (many types) osteoporosis.

• Primary osteoporosis has been

– menopausal changes (type I),

– age-related changes (type II),

– idiopathic causes (type III).

• Secondary osteoporosis has been attributed to many different diseases

and conditions, including diabetes, alcoholism, malnutrition, and

smoking(Glaser DL 1997)

In osteoporosis there is decreased bone mineral density, so impair

the patient's ability to achieve and maintain implant osseointegration.

osseointegration depends on bone formation adjacent to the implant surface

and success rates are highest in dense bone and lowest in poor-quality, loose

trabecular bone.

longer healing time for osseointegration to occur before loading the implants in

patients with osteoporosis.[Mellstrom D,2001]

• Aging adults (men over 50 years and postmenopausal women) their bone

mass decreaseses at demineralization rate of 1% to 2% per year and in

some individuals as much as 5% to 8% per year throughout their later

life so the chance of implant failure also increases in the same

rate.[Hildebolt CF1997]

• Medications:-

• Medications, including steroids and bisphosphonates, cause of

concern for implant patient.

• Corticosteroid therapy, used for hormone replacement, and

cancer treatment,or immune suppression suppresses the

– immune response,

– impair wound healing or

– compromise the normal adrenal response to stressress.

• Bisphosphonate used in cancer therapy cause great concern about risk of

bisphosphonate-related osteonecrosis of the jaw (BRONJ),

• In general, the risk of BRONJ is 1 in 100,000 but may increase to 1 in

300 after an oral surgical procedure. The majority of BRONJ occur in

patient using intravenouly with having Co-factors, such as smoking,

steroid use, anemia, hypoxemia, diabetes, infection, and immune

deficiency[Marx RE 2007]

•

• Procedures that contributed to the development of BRONJ include

extractions, periodontal surgery, root canal treatment, and dental implant

surgery.[Marx RE, and Fortin M 2005]

• Dental implant therapy, as well as other surgical procedures, should be

avoided in individuals who have been treated with intravenous (IV)

bisphosphonate therapy for more than 3 years (Assael LA 2009).

• Immune Compromise and Immune Suppression:-

• Individuals undergoing chemotherapy or taking medications that impair

healing (e.g., steroids) and increases infection chances are not good

candidates for implant therapy.

• Patients with very low or undetectable viral loads and normal (T cell

counts) immune function may be candidates for implant therapy.

• Past history of chemotherapy or immunosuppressive therapy are not

problematic if the patient has recovered from the side effects of treatment.

• Patients with an immunocompromising disease, such as human

immunodeficiency virus (HIV) infection or acquired immunodeficiency

syndrome (AIDS), are not good candidates for implants, especially when

their immune system is seriously impaired.

• Radiation Therapy:-• Patients with a history of radiation treatment to the head and neck

region may not heal well after surgery.

• Soft tissue dehiscence may follow surgical manipulation, which may lead to osteoradionecrosis (ORN).

• This is especially problematic for patients who have received radiation dosages greater than 60 Gy.

• Surgical procedures, or any procedure that may initiate a wound, are generally avoided in patients with a history of radiation therapy.

• If deemed necessary, surgical procedures can be done in conjunction with hyperbaric oxygen (HBO) therapy to reduce the risk of ORN.

• Studies have documented poor success rates for implants

in patients with a history of radiation therapy.[Granstrom

G 1999]

• Sennerby and Roos1998 found irradiation to be associated

with high failure rates.

• Beumer et al 1995 reported success rates as low as 60.4%

in the irradiated maxilla.

• Granstrom et al 1993 reported a significant improvement

in survival rates for implants in patients treated with HBO.

• Habits and Behavioral Considerations:-

• Smoking, clenching or grinding of teeth, and drug or alcohol

abuse are among the most well-known habits that should be

identified because of the increased risk for implant failure or

complications.

• Smoking and Tobacco Use:-

• Moderate to heavy smoking has been documented to result in higher

rates of early implant failure and adversely affect the long-term

prognosis of dental implant restorations.[Bain CA 1993]

• particularly when implant is placed in poor quality bone such as the

posterior maxilla (Han TJ 2007).

• Becouse effect of smoking – on white blood cells,

– vasoconstriction,

– wound healing,

– Osteoporosis (Ericsson I 1993)

• . Smoking cessation improves the success rate of implants.[Bain CA

1996]

• Parafunctional Habits:-

• Parafunctional habits, such as clenching or grinding of teeth

(consciously or unconsciously) have increased rate of implant failure.

• Repeated lateral forces (i.e., parafunctional habits) applied to implants

can be detrimental to the osseointegration process, especially during the

early healing period..

• Bain 1996 considered bruxism as contraindication to implant treatment,

especially in the case of a short-span, fixed partial denture or a single-

tooth implant.

• If implants are planned for a patient with parafunctional habits,

protective measures should be employed, such as creating a narrow

occlusal table with flat cusp angles, protected occlusion, and the regular

use of occlusal guards

• Posttreatment Evaluation:-

• Periodic posttreatment examination of implants, the retained prosthesis,

and the condition of the surrounding periimplant tissue is an important

part of successful treatment.

• Aberrations and complications can often be treated if discovered early,

but many problems will go unnoticed by the patient.

• Thus periodic examination is essential to discovering problems early.

• Several parameters are available to evaluate the condition of the

prosthesis,

– stability of the implant(s),

– health of surrounding periimplant tissues after implant integration and

prosthetic restoration.

• other clinical measures are clinical inspection, probing, and radiographic

examination.

• Clinical Examination:-

Clinical examination includes visual inspection and probing.

Visual evaluation of the tissue include

Color

contour

consistency,

They can also be palpated to detect areas of edema, tenderness

and exudate for any inflammation or swelling .

• Periimplant Probing:-

• Periodontal probing around natural teeth is very useful to assess the health of periodontal tissues, the sulcus or pocket depth, and the level of attachment(Bragger U 1997)

• Clinicians should use caution during periimplant probing because of distinct differences in the surrounding tissues that support implants compared to those that support teeth.

• Around teeth, the periodontal probe is resisted by the health of the periodontal tissues by the insertion of supracrestalconnective tissue fibers into the cementum of the root

surface.• These fibers are unique to teeth, are the primary source of

resistance to the probe (Armitage GC 1997)

• Connective tissue fibers around implants generally run parallel to the

implant or restorative surface and do not have perpendicular or inserting

fibers (Ericsson I 1993)

• At noninflamed sites, the probe will be resisted by the most coronal

aspect of connective tissue adhesion to the implant. At inflamed sites, the

probe tip consistently penetrates farther into the connective tissue until

less inflamed connective tissue is encountered, which is often close to or

at the level of bone.

• However, periimplant probing is affected by several conditions, including

the size of the probe, the force and direction of insertion, the health and

resistance of periimplant tissues, the level of bone support, and the

features of the implant, abutment, and prosthesis design.

• Probing around implants is likely to be more variable than

around teeth; studies have shown that change in probing force

around implants results in more loss of tissue than around teeth

(Mombelli A 1997).

• 3 mm of probing depth around implants presumed to be

“healthy” (and without bleeding)(Adell R 1981)

• The absence of bleeding on probing around teeth has been

established as an indicator of health and a predictor of

periodontal stability (Lang NP 1990).

• Microbiologic studies suggest that greater probing depth or

“pockets” around implants harbor higher levels of pathogenic

microorganisms (Mombelli A 1987)

• Microbial Testing:-

Studies have demonstrated the development of periimplant mucosal

inflammation in response to the accumulation of bacterial plaque

(Berglundh T, Lindhe J 1992)

similarities in the microbial composition of plaque in healthy

periodontal sites compared with healthy periimplant sites (Mombelli A

2000)

microbiota of inflamed periimplant sites (periimplantitis) harbors the

same periodontal pathogenic microorganisms as those observed in

diseased periodontal pockets(Sanz M 1990) .

The usefulness of microbial testing may be limited to the evaluation of

periimplant sites that are showing signs of infection and bone loss, so

the clinician can prescribe appropriate antibiotics.

• Stability Measures:-

• The assessment of implant stability (or mobility) is an important

measure for determining whether osseointegration is being maintained.

• however, this measure has extremely low sensitivity but high

specificity.

– That is, a large amount of bone loss can occur around an implant, but the

implant remains stable .

– On the other hand, if significant mobility is detected, the implant has likely

failed.

• So evaluating the stability of the bone-to-implant contact in a non

invasive manner. Two techniques that have been used are:-

– impact resistance (e.g., Periotest) and

– resonance frequency analysis (RFA).

• periotest

• Periotest (Gulden, Bensheim, Germany) is a noninvasive, electronic

device that provides measurement of the reaction of the

periodontium to a defined impact load applied to the tooth crown.

• The Periotest value depends to some extent on tooth mobility but

mainly on the damping characteristics of the periodontium.

• Despite the dependence on the periodontium, the Periotest has been

used to evaluate implant stability as well.

• However, unlike teeth, the movement of implants and the

surrounding bone is very little, and therefore the Periotest values

fall within a much smaller range compared to the range found with

teeth.

• Used for detection of horizontal mobility because it is more

sensitive to horizontal movement than by other means, such as

manual assessment (Lekholm U 1998)

• Resonance frequency analysis (RFA) :-

• another noninvasive method used to measure the stability of implants

(Meredith N 1996)

• Uses a transducer that is attached to the implant or abutment. A steady-

state signal is applied to the implant through the transducer, and a

response is measured.

• The RFA value is a function of the stiffness of the implant in the

surrounding tissues.

• The stiffness is influenced by the implant, the interface between the

implant ,bone, soft tissues as well as the surrounding bone, height of the

implant or abutment above the bone

• Unlike the Periotest, the RFA is not dependent on movement in only one

direction.

• Absolute RFA values vary from one implant design to another and from

one site to another, but there is high consistency for any one implant or

location.

• it is very sensitive to changes in the bone-implant interface. Small changes

in tissue support can be detected using RFA.

• An increase in RFA value indicates increased implant stability, whereas a

decrease indicates loss of stability.

• However, this is a relative measure and it has not been determined

whether RFA is capable of detecting impending failure before the implant

actually fails.

• Mobility remains the cardinal sign of implant failure, and detecting

mobility is therefore an important parameter.

• Radiographic Examination:-

• Intraoral radiographs should be taken at the time of

– placement (baseline),

– abutment connection (confirm seating and serve as another

baseline),

– final restoration delivery (loading),

– subsequently to monitor marginal or periimplant bone changes.

• Periapical radiographs have excellent resolution and provide

adequate details for evaluating bone support around implants if

taken at a perpendicular direction.

• The limitation of periapical radiographs is that they are difficult

to standardize, and great variability in the acquisition process

• Periapical films are relatively simple, inexpensive, and readily

available in the dental office.

• The objective of the radiographic examination is to measure the height of

bone adjacent to implant(s) and evaluate the presence and quality of bone

along the length of the implant.

• Finally, the periimplant areas are assessed for any radiolucent lesions

around the implant.

• Although the predictive value of assessing implant stability with radiographs

is low, but offer a reasonable method to measure changes in bone levels

(Sunden S 1995)

Radiographic identification of unstable implants is reliable when performed

as part of frequent examinations (Lekholm U 1997).

• Friberg B 1991 demonstrated much higher predictive value for radiographic

diagnosis of implant failure and concluded that it is most important factors

for making an accurate radiographic diagnosis but depends on

– quality of the radiograph

– experience of the clinician (Lekholm U 1997)

• Oral Hygiene and Implant Maintenance:-

• The long-term success of dental implants requires the maintenance of

healthy periimplant tissues because the soft tissue “seal” around

implants is best when the surrounding mucosa is not inflamed.

• The importance of good oral hygiene should be stressed even before

implants are placed, and oral hygiene instructions for plaque control

should begin as early as possible.

• The patient's ability to maintain good oral hygiene should be monitored

and reinforced at each visit, and the patient should be given instructions

specific to individual needs

• Implant superstructures, frameworks, and restorations should be

fabricated to facilitate oral hygiene (e.g., embrasure spaces

should be made to allow the passage of a proxy brush).

• Initially, for the first year after treatment is completed, recall

maintenance visits should be scheduled at 3-month intervals and

then adjusted to suit the patient's individual needs.

• Some patients, with good oral hygiene and minimal deposits, will

require infrequent professional hygiene maintenance, whereas

others, with poor oral hygiene and heavy deposits, will require

more frequent follow-up care.

Plastic and gold-coated curettes should be used to protect the titanium implant surface and the titanium abutment from contamination and scratching by other metals.

Plastic curettes do not work very well, and gold-coated curettes cannot be sharpened.

Most current implant prostheses are made with gold alloys or ceramic materials, can be debrided with most scalers and curettes (plastic, gold coated, stainless steel) without damaging the surface.

Rotary instruments (e.g., prophy cup) can be used to remove plaque or biofilms and polish surfaces.

The use and sonic instruments (e.g., Cavitron) should be avoided because of irregularities that can easily be created in the surface, which can contribute to plaque and calculus accumulation.

One advantage of using screw-retained implant restorations (e.g., super

structures, overdenture bars, fixed prosthesis, etc.) is that they can be removed,

cleaned outside the mouth, and replaced.

• Recall maintenance visits should include an

– evaluation of soft and hard tissue health,

– level of oral hygiene compliance and plaque control,

– prosthesis integrity and stability, and implant stability.

– Implant stability can be evaluated with a combination of mobility testing and radiographic

assessment.

• Thank you

Implants

Health & Medicine

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