1、2023-2-1112023-2-112 IntroductionComplications may occur in both the surgical and prosthodontic phases of implant therapy.It is essential to warn patients of the possibility of surgical and postoperative problems.2023-2-113 IntroductionFailure of osseointegration is relatively rare in well-planned c
2、ases,with most failures occurring soon after surgical placement or before loading.2023-2-114IntroductionComplications in most cases are avoidable by careful attention to diagnosis,treatment planning and good surgical and prosthodontic planning,and by following established protocols of individual imp
3、lant systems.2023-2-115 Surgical complications The more common,relatively minor complications following surgery include swelling,bruising and discomfort.All patients should be warned of these complications and the anticipated extent of them before surgery is undertaken.2023-2-116 Surgical complicati
4、onsAs with all minor surgical procedures,surgical complications can be minimised by adequate aneasthesia,gentle surgical manipulation of both hard and soft tissues,pre-and postoperative analgesia,and careful postoperative wound management,including the use of pressure and ice packs to reduce swellin
5、g.2023-2-117 Surgical complicationsHaemorrhage may occur at the time of surgery if there is excessive trauma to soft tissue or damage to aberrant vessels within the bony cortex.2023-2-118Surgical complicationsFailure to establish good primary stability at the time of implant placement may result in
6、early failure.2023-2-119Surgical complicationsIncorrect positioning of implants at the time of surgery,as a consequence of poor planning or lack of necessary skills,knowledge and understanding may result in considerable difficulties during the restorative phase of treatment.2023-2-1110Surgical compl
7、ications It is essential to use surgical guides and templates if positioning problems are to be minimised.2023-2-1111Postoperative PainMild postoperative pain is to be expected.It should,however,be readily controlled by means of non-prescription analgesics.Severe pain following impalnt surgery is ex
8、tremely rare.2023-2-1112Postoperative PainPatients with pain after 24 hours should be monitored for signs of infection,bleeding and other complications.In such situations there well be an increased risk of implant failure.2023-2-1113Postoperative PainThe routine use of antibiotics pre-and postoperat
9、ively will decrease the posibility of infection.The practitioner must,however,be satisfied as to the indications to prescribe prophylactic antibiotics.2023-2-1114Wound DehiscenceIn the two-stage surgical technique,breakdown of the soft tissue following implant placement may lead to the exposure of t
10、he implant and cover screw.2023-2-1115Wound DehiscenceThis may be the result of poor soft-tissue coverage of the implant or trauma from the prosthesis covering the surgical site.2023-2-1116Wound DehiscenceThe diagnosis of the cause of soft tissue breakdown needs to be established when palnning furth
11、er management of the case.In all cases the surgical sites must be kept clean with antiseptic mouthrinses,such as chlorhexidine,used as indicated clinically.2023-2-1117ParaesthesiaParaesthesia may arise following trauma to nerves in the region of the implant site.The trauma may be direct from drillin
12、g through,or at least into a structure,or indirect as a result of excess heat generation.2023-2-1118ParaesthesiaWhatever the cause,trauma to sensory nerves may lead to loss of sensation to the lower lip.2023-2-1119ParaesthesiaPermanent loss of sensation may be the result of damage to the inferior de
13、ntal nerve.This should be avoided through careful radiographic assessment and including a safer margin for possible error in the planning of implant placement.2023-2-1120Damage to the incisive branch of the inferior dental nerve may result in patients complaining of paraesthesia or anaesthesia to an
14、y remaining lower incisors.Paraesthesia2023-2-1121Mandibular FracturesIn severely resorbed mandibles multiple implants may weaken the jaw with a resultant fracture.This is,however,very rare in suitably planned cases.2023-2-1122Complications Following Second-Stage SurgerySecond-stage surgery involves
15、 uncovering of the implant,removal of the cover screw,replacing it with a healing abutment and careful suturing of the soft tissues around the abutment.2023-2-1123Complications Following Second-Stage SurgeryA careful and gentle surgical technique is essential in minimising complications,notably poor
16、,unaesthetic gingival contour.2023-2-1124Failure to IntegrateMobility of an exposed implant is indicative of failure of the implant to integrate.The implant and many associated soft tissue should be removed.2023-2-1125Failure to IntegrateImmediate placement of a larger diameter implant may be consid
17、ered.It may be prudent,however,to leave the site to heal,with time to replan treatment.2023-2-1126Excessive Bone over the Cover Screw Occasionally the cover screw can be partially covered by bone.This bone needs to be cleared away before attempting to remove the cover screw.Most implant systems supp
18、ly a bone mill for this procedure.2023-2-1127Bone Growth between the Cover Screw and ImplantIf the cover screw has not been placed directly onto the implant head at the time of first-stage surgery,bone may grow into any gap left between implant head and cover screws.2023-2-1128Bone Growth between th
19、e Cover Screw and ImplantImplant systems include a bone mill for the careful removal of bone from the implant head and thereby provide a clear path of insertion for the abutment.2023-2-1129Prosthetic ComplicationsImplant prosthodontics can be relatively uncomplicated when fixture angulation and posi
20、tioning is ideal.2023-2-1130Prosthetic ComplicationsIn most cases,complications can be avoided by means of careful preoperative treatment-planning and meticulous attention to detail,both clinically and in the laboratory.2023-2-1131Biomechanical Problemsthey may include:fracturing of the prosthesis l
21、oosening or fracturing of abutment screws2023-2-1132 Biomechanical Problems loosening or fracturing of gold screw lute failure in a cement-retained prosthesis fracture or loss of the implant2023-2-1133Fracture of the prosthesisFracture of a fixed implant superstructure is often the result of misjudg
22、ed space,leading to thin sections of materials,errors in technical procedures or the generation of excessive stresses in poorly placed prostheses.2023-2-1134Fracture of the prosthesis Partial loss of acrylic or porcelain and fracture of the metal framework is more often than not the result of excess
23、ive loading or poor design of the framework.2023-2-1135Fracture of the prosthesisLong cantilevers can lead to both fracture of the prosthesis and screw-loosening.As with fracture of any restoration,the cause of the failure must be diagnosed before planning remedial treatment.2023-2-1136Loosening or
24、Fracturing of ScrewsOverload,poor fit of framework or components and excess or inadequate tightening are all reasons for the loosening or fracturing of screws.Prescribed protocols must be followed to retrieve and replace fractured screws successfully.2023-2-1137Lute Failure in a Cement-Retained Pros
25、thesisExcessive loading and poor fit of the superstructure are the most common causes for this type of failure.2023-2-1138Lute Failure in a Cement-Retained Prosthesis Remedial treatment may include repositioning the superstructure to improve fit.Repeated cement failure may necessitate a remake of th
26、e prosthesis.2023-2-1139Fracture or Loss of the ImplantBone loss may continue to a level at which inherent weaknesses in the implant result in fracture.Excessive loading may result in loss of integration.2023-2-1140Fracture or Loss of the ImplantFurther treatment under such circumstances is highly d
27、ependent on the particulars of the case.Removal of a fractured implant may be problematical.2023-2-1141Physiological ProblemsPhysiological problems may include:soft-tissue inflammation-peri-implant mucositis and peri-implantitis bone loss resulting in implant thread exposure-depending on severity 20
28、23-2-1142Physiological Problemsbone loss may necessitate implant replacement loss of integration implant removal and perhaps replacement.2023-2-1143MaintenanceThe importance of a carefully planned,fully adhered-to maintenance programme cannot be overemphasized in the long-term management of implant-
29、retained prostheses2023-2-1144Maintenance In the assessment and treatment-planning of implant cases,it is essential that patients take responsibility for the long-term care of their prostheses.2023-2-1145MaintenanceA degree of dexterity will be needed for the patient to clean the prosthesis adequate
30、ly,and this must be carefully assessed at the treatment-planning stage.2023-2-1146MaintenanceFailure or the inability of patients to maintain and look after their implant-retained prosthesis may lead to many varied problems,including failure in clinical service.2023-2-1147MaintenanceIt is essential
31、that baseline radiographs are taken at completion of treatment.Progressive bone loss may be related to excessive loading.2023-2-1148MaintenanceMost implant systems show a small amount of bone loss in the first year after loading,but should remain stable thereafter.2023-2-1149Maintenance It is theref
32、ore recommended that all patients be seen three months after the completion of treatment,when careful clinical examination is indicated.This should include:assessment of the prosthesis examination of the soft tissues radiographic examination to assess bone height.2023-2-1150The Prosthesis Clinical e
33、xamination of the prosthesis should in addition to checking fit,stability,occlusal relationship and patient acceptability focus on the sufficiency of the patients oral hygiene.2023-2-1151The ProsthesisThere are numerous aids that can be used to clean around the prosthesis and implant abutments.2023-
34、2-1152The ProsthesisThese range from conventional to electric toothbrushes,floss and super floss and various interdental brushes and related devices.2023-2-1153The ProsthesisThe patient should be encouraged to maintain a high level of oral hygiene around the prosthesis and receive detailed oral hygi
35、ene instructions.2023-2-1154The soft tissuesEvaluations of soft tissues surrounding implant abutments should be both systematic and detailed.2023-2-1155The soft tissuesGentle probing should not result in bleeding or exudate.A standard periodontal probe may be used to evaluate probing depths.This wil
36、l depend on the thickness of the original mucosa.2023-2-1156The soft tissuesAny overgrowth of soft tissue or any loss of attachment that may have occurred will result in increased probing depths.2023-2-1157The soft tissuesMost inflammatory conditions can be managed by careful attention to oral hygie
37、ne,aided and supported by professional advice and assistance.2023-2-1158The soft tissuesAny deposits that have built up must be removed by the practitioner or by a trained hygienist.There are numerous instruments available on the market to aid removal of any hard deposits around implants.2023-2-1159
38、The soft tissuesThese may be of plastic or carbon-reinforced designs.The use of ultrasonic and metal-tipped scalers is contraindicated.2023-2-1160 The soft tissuesLong-cone radiographs should be taken:at baseline on completion of treatment at three months and one year postoperatively.2023-2-1161The
39、soft tissuesIf there is radiographic evidence of bone loss during the first year in clinical service,subsequent radiographs should show very little change.2023-2-1162 The soft tissuesProgressive bone loss is not usually associated with implant-retained prosthesis.Any progressive bone loss should be
40、cause for concern and encourage the practitioner to assess the sufficiency of the prosthesis.2023-2-1163The soft tissuesSoft-tissue inflammation(mucositis)is sometimes seen around poorly maintained and loose prosthesis.If the prosthesis is loose it will be necessary to remove it,clean it in an ultra
41、sonic device and securely replace it in the mouth.2023-2-1164The soft tissuesSoft-tissue proliferation may occur around poorly designed and ill-fitting superstructures.If such proliferation dose not respond to local oral hygiene measures it may be necessary to excise the unwanted tissue,possibly as
42、part of remedial treatment to replace the superstructure with an appropriately designed,well-fitting prosthesis.2023-2-1165The soft tissuesPeri-implantitis a peri-implant inflammatory condition resulting in progressive bone loss is a rare occurrence in well executed and maintained cases.Diagnosis of
43、 peri-implantitis may be confirmed by means of long-cone radiographs.2023-2-1166The soft tissuesBone loss is usually circumferential,resulting in gutter bone loss.The cause of peri-implantitis is not fully understood,but it may be a combination of excess of or inappropriate occlusal forces in the pr
44、esence of pathogenic bacteria in an unfavourable oral environment.2023-2-1167The soft tissuesThe management of peri-implantitis involves:careful assessment of the occlusion in the intercuspal position and eccentric movementsexamination and cleaning of exposed implant surfaces.If there has been tissu
45、e proliferation around the implants,this may need to be removed 2023-2-1168The soft tissuesremoval,cleaning and servicing of the restorations as may be indicated clinicallyinstruction of the patient in effective oral hygiene proceduresmonitoring and further oral hygiene and prosthesis maintenance in
46、struction as necessary.2023-2-1169The soft tissuesIf peri-implantitis persists and progresses despite the above measures,the case should be critically reviewed and,if required,the patient referred for specialist care.2023-2-1170ConclusionsComplications are rare fall into two main groups surgical and
47、 prosthodontic.The practitioner should be fully aware of any possible complications prior to treatment and inform the patient accordingly.2023-2-1171ConclusionsThe cause of prosthodontic complications should be carefully assessed,diagnosed and rectified.The maintenance of implant patients should include regular reviews involving radiographic examinations.
