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ePaper created 2015-09-23, 22:57:38 | version 1.38.0
science & practice 11EAO Annual Scientific Congress 2015 · 24 September Teeth are highly evolved struc- tures that have developed progres- sively over millions of years in at- tempts to protect themselves from caries and periodontal diseases. Over the years many advances have been made which can treat these various diseases predictably. Variousstrategieshavebeendevel- opedtopreventorslowdownthese problems given enough patient compliance and appropriate per- sonal and professional mainte- nance. Despite these very signifi- cant improvements there are still instances when patients get told ‘this tooth or these teeth need to go’. It is the obvious sadness, heartache or despair that patients are caused by this bad news that has driven caring clinicians to find ways to replace teeth with various devices from dentures, to bridges to implant retained prostheses. P. I. Brånemark, now sadly de- ceased, famously quipped ‘No one should have to die with their teeth inaglassofwaterbesidetheirbed’. Brånemark’s original inspiration coupled with determination, intu- ition, passion and an ability to sur- round himself with a great team of individuals with differing skills madeosseointegration muchmore predictable.Brånemark’slandmark studies changed prosthetic den- tistry dramatically but a careful lookatthedesignoftheseprotocols andtheimplantsthemselvesreveal werehugelydifferenttothepatient selectionprotocolsandthetypesof implants being placed today. Fur- thermore, the restorations sup- portedonthemweremadeofthees- tablished materials then and obeyed traditional mechanical laws. In terms of biologic cleans- ability, the metal polished ‘highwa- ter’ abutment design allowed for optimal interproximal cleaning whilst the implant surface itself was also relatively smooth in com- parison to the rougher surfaces we often see today. Market saturation, cost, profit, and market share in many technological driven mar- kets often drive innovation of some sort of change to help gain greater market share or profit. Theover-commercialisationofden- tistry generally creates a constant turnover of supposedly “new and better” products where the com- mon quote ‘if it ain’t broke don’t try to fix it’ is lost on many directors of marketing or increasingly profit driven CEO’s. Why and where? Thesearchingquestionneedsto be asked, “where has this techno- logical change taken implantology and what are the real reasons why this was and is happening?” In- creasingly, the shadow of peri-im- plantitis looms likes a spectre over the provision of implants. Unlike caries or periodontal disease there is very little consensus or research thatcanprovideapredictablecure for what now is now a new breed of diseases. Peri-implantitis is relent- less once established within fine threadsoftheimplantandthebone resorptionandsofttissueproblems that follow can result in spectacu- lar problems. Part of the key issue probably lies in the surface ex- posed to the susceptible patient’s oral environment, as most microbi- ologists will allege. The bacterial contentandmake-upofthebio-film is a reflection of the surface that it resides on. Implant surfaces have become progressively rougher in order to hasten the early osseointe- gration processes and to try to pro- videpatientswiththeirrestoration quicker in an ever more competi- tive financial environment. How- everspeedisnotalwayshelpful.Ex- perience shows that some things are better taken slowly over time - rather similar to making love. Once exposed to the environ- ment of a susceptible patient the macro topography of the threads provideanidealecologic nichefor bacterial proliferation. Further nano-level features make the im- plantsurfaceaveritable‘inflamma- tion super highway’ for the patho- genic organisms. Predictably enoughthemicro-organismsfound on the rough surface are usually the common pathogenic ones but also some species are found that havepreviouslyneverbeendiscov- ered in the oral cavity. Patient selection issues Weneedtoconsiderthetypesof patients for whom we are now ac- cepting for implant provision. At King’sCollegeHospitalthecriteria for state sponsored implant provi- sion largely involves patients with hypodontia and those who have suffered trauma. Usually both co- horts are likely to pres- ent with well- maintained minimally restored dentitions or with scope for oral health improvement prior to the consideration for any restoration letaloneanimplant.Unfortunately we are unable to provide this treat- ment for smokers. This is in stark contrast to patients who may be provided with implants in general and specialist practice for patients who are likely to have lost teeth as a result of plaque associated dis- eases. Indeed it could be consid- ered a paradox by many interested observers that some clinicians are providingpatientswithimplantre- tained restorations when have shown that they are highly prone to plaque associated disease via tooth loss and have not demon- stratedanyrealcapacityforchang- ingthat.Patientswhosmoke,those with a history of periodontitis and those with poor oral hygiene are well known to be at a very signifi- cantly higher risk of peri-implanti- tis (Alani et al. 2014). Biological versus mechanical problems If we are being frank the patho- genic bacterial induced diseases arenottheonlylong-termproblem that we now see. The reported fre- quency of mechanical complica- tions has risen over the years but the reported problems are proba- bly only the tip of the iceberg as many complications have not and will not be reported for a variety of understandable reasons. Over time the components of im- plants have shown notable weak- nesses. Screw loosening, fractured screws, loose abutments and the cracking of ceramic can be labori- ous and expensive to manage. One aspect,whichmaybelostonsomeis that,lackingaperiodontalligament dental implants, cannot and will never be able to acclimatise to changing occlusal and non-axial forces. These are very likely to cre- ate stresses within the masticatory system thereby resulting in break- ages. These forces are compounded greatly if patient’s parafunction on a daily basis and that is sometimes anunknownriskfactoruntilitistoo late. The more implants that are placed usually the fewer teeth are present resulting in a net reduction in physiological feedback and thereby creating an increased chance of failure of some type. Ethical,moral and legal issues These problems become much more worrying when viewed from ethical, valid consent and medico–legal perspectives. This is particularly so when patients are convinced to undergo elective ex- tractions of teeth which often seem reasonably intact and/or treatable with conventional proven treat- ment strategies. It seems that there is a worrying drift towards aggres- sive treatment with extractions in order to provide a supposed “full mouth rehabilitation” with multi- pleimplants.Theincreasinglydubi- ous practiceofsacrificingteethfor the sake of implants seems to many concerned clinicians to be quite ir- rational.Asethicaloralhealthprac- titioners, deliberately removing saveable teeth for prosthetic re- placement using implants as sup- port seems to be consciously flying in the face of increasingly apparent evidence of various complications withimplantsandmanywouldcon- sider that approach to be foolish. How many “implantologists” doing thattootherswouldgenuinelyhave it done to themselves or done to some close family member? Planned obsolescence Astateoftheartimplanttodayis likelytobeobsoletetomorrow.Elec- tively removing teeth is irre- versible and replacing teeth with implant retained devices means that patients are trapped in the era of Implantology in which these were placed and restored, that meansissuesofmachining,surface blasting, roughness, platform switching, design and attempts at boneaugmentationbycow,coralor Californian substances. The list goes on and on and will probably continue to expand with what many would call “human experi- mentation without licence”. Now comes the time for implant manufacturers to take stock of their many “market driven” mis- takesincluding“fastinitialintegra- tionwiththeroughestpossiblesur- faces”. Instead they need now to produce proven (i.e. not specula- tive) designs to better prevent thesenowwellknownproblemsof infection and breakages. A wiser, pragmatic approach seems to be to concentrate every- one’s efforts on saving teeth and thereby eke out their usefulness for the patients’ lifetime. Recently, the legendary Jan Lindhe writing in the British Dental Journal sum- marised the state of play as ‘There is an overuse of implants in the world and an underuse of teeth as targets for treatment’. Dental implantology:Evolution or the road to ruin? By DrAwsAlani,UK Aws Alani qualified from Kings in 2003 and after hospital and practice positions com- pleted his MSc from the Eastman Dental Insti- tute in 2006. He subsequently completed spe- cialist training in Restorative Dentistry after- which he became an ITI Scholar in Toronto, Canada. In 2014 he was appointed Consultant in Restorative Dentistry at Kings College Hos- pitalandisleadclinicianforthemanagement of congenital abnormalities. ©Alex Mit/Shutterstock.com