The use of dental implants over the last 20 years or so has provided a technique for improving the life and masticatory efficiency of many patients.
Previously, when a tooth had to be extracted it could only be replaced by a denture or a bridge.
Both of these techniques have their own advantages and disadvantages as discussed earlier in the chapter, but a reminder of the main disadvantages of each is summarised below.
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Dentures – poor retention, making chewing and successful wear very difficult.•
Bridges – permanent loss of tooth tissue while preparing abutment teeth, and overloading of remaining teeth causing the eventual failure of the bridge.The development of dental implants as an alternative to the replacement of missing teeth has helped to overcome these disadvantages.
An implant is effectively a titanium double-screw cylinder that is inserted into a hole drilled into the alveolar bone of either jaw, to replace one or several teeth. Unlike when posts are cemented into tooth roots when placing post crowns, the implant is not ‘glued’ into place.
Instead, the alveolar bone gradually grows around it and into its hollow screw structure so that it is eventually locked into the bone itself. This is called osseointegration and takes several months to occur.
Once the implant is firm within the bone structure, the top section can have the tooth replacement screwed onto it, and this can be any of the following devices.
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Single crown tooth.•
Multiple crowns to form a bridge.•
Metal bar to act as a locking device beneath a denture.•
Metal ball to act as a locking device beneath a denture (Figure 16.58).(a) (b)
Figure 16.58 Implant components. (a) Ball abutment for overdenture. (b) Implant fixture.
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The success of the use of implants depends on many factors.
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Bone – there must be a deep enough section of alveolar bone to screw the implant into, without it damaging other structures such as dental nerves or the maxillary antrum (although techniques are being developed to replace bone using synthetic alternatives, and an operation can be performed to ‘raise’ the floor of the antrum to provide more space).•
Patient selection – not all patients will be suitable for such an extensive surgical procedure;some medical conditions may also contraindicate the use of implants (such as osteoporosis, haemophilia, diabetes due to poor wound healing).
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Oral health – patients with poor oral health are unsuitable for implants, as their success depends very much on being kept clean of dental plaque. The presence of plaque allows periodontal disease to develop around the implant, and the resultant pocketing will allow the titanium cylinder to become loose and the implant will fail – this condition is called perimplantitis.•
Lifestyle factors – factors such as smoking and poor dental attendance may lead to failure of an implant in the same way that they are associated with higher levels of dental disease ( especially periodontal disease) in dentate patients without implants.Implant and prosthesis placement procedures
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A team consisting of an implantologist, a specialist technician and a hygienist examine and assess the patient, helped by study models, radiographs or even three-dimensional computer scans.•
They can then plan the preparation, construction and maintenance of an implant procedure for the patient.•
Depending where the placement procedure is carried out, local anaesthetic (with or without conscious sedation) or general anaesthetic is given to the patient.•
The oral surgery procedure of inserting the titanium implants into the alveolar bone is carried out under the usual surgical conditions of other minor oral surgery procedures.•
A mucoperiosteal flap is raised to expose the bone and special low-speed drills are used to prepare holes for the implants, or the extraction socket of the tooth itself is used and prepared in a similar fashion.•
The implants are screwed into the prepared holes and the tissue flap is then sutured back into place to completely bury the implant (Figure 16.59).•
After a suitable time period, which can be up to several months, the implants become firmly embedded in the bone by osseointegration, and the prosthesis can be placed.•
Under local anaesthetic, a small incision is made in the overlying gingiva to expose the top of each implant, and the artificial abutments are then screwed into the inner surface of the implants. Abutments may be in the form of stumps for fitting single crowns or bridge pontics (Figure 16.60) or a ball or bar for clipping on a removable overdenture.Obviously, the succesful placement of implants in dentistry depends on the surgical skill of the dentist or oral surgeon involved. Training available ranges from weekend courses, through module type diplomas, to full surgical specialty and qualification. The more complicated cases should only ever be handled by those with adequate training in the more complicated techniques, and specialist implantologists.
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In addition, the laboratory stages of the top section of the appliance have to be carried out by specialist technicians, although the chairside preparation stage is no different from that for a conventional crown or bridge preparation. The use of denture locking devices requires special impression techniques to be used.
The need for specialist training in dental implants, as well as all the necessary equipment required, means that implants are very expensive to place. The simplest case of a single tooth implant is usually in the region of £1500–2000 (at 2013 prices), and the more complicated cases will run into tens of thousands of pounds each. Their only availability on the NHS is as teaching cases in dental hospitals.
However, their use is on the increase as they provide succesful dental treatment options to patients who were previously untreatable, as well as offering less invasive techniques in simpler
(a) (b)
Figure 16.60 Implant procedure. (a) Stage 1: implant fixture. (b) Stage 2: crown or bridge abutment fitted.
Figure 16.59 Radiograph of implant placement.
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cases, such as single tooth replacements. Training courses are currently being developed for qualified dental nurses, so that they are able to assist in specialist implant clinics and hospital departments.
In the meantime, the dental nurse has an important role in helping to provide oral hygiene instruction and reinforcement for implant patients, in a similar way to that given for crowns, dentures and bridges.
Further resources are available for this book, including interactive multiple choice questions and extended matching questions. Visit the companion website at:
www.levisonstextbookfordentalnurses.com
Levison’s Textbook for Dental Nurses, Eleventh Edition. By Carole Hollins.
© 2013 John Wiley & Sons, Ltd. Published 2013 by John Wiley & Sons, Ltd. Companion website: www.levisonstextbookfordentalnurses.com
Many procedures carried out daily in the vast majority of dental workplaces can be collectively termed as ‘minor oral surgery’ (MOS), as opposed to major oral surgery procedures such as treatment and reconstructive surgery for oral cancer, orthognathic surgery to correct skeletal problems, and head and neck trauma surgery. Those minor surgical procedures to be discussed here are the following.
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Simple extractions – of roots or whole teeth, where no soft tissue or bone removal is required.•
Surgical extractions – of roots or whole teeth, where soft tissue alone, or with bone, has to be removed to gain access to the root or tooth.Extractions and Minor Oral Surgery
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Key learning points
A factual knowledge of
• simple extraction techniques
• surgical extraction techniques A working knowledge of
• the instruments and equipment used in simple tooth extractions
• the instruments and equipment used in surgical extractions and minor oral surgery procedures
A factual awareness of
• the complications of extraction and their avoidance
• other minor oral surgery procedures
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Operculectomy – the surgical removal of the gingival flap overlying a partially erupted tooth, especially a lower third molar.•
Alveolectomy - the surgical adjustment and removal of bone spicules from the alveolar ridge after tooth extraction, to produce a smooth base for denture seating.•
Gingivectomy and gingivoplasty – periodontal soft tissue surgery to adjust the shape of the gingivae to aid oral hygiene measures.•
Periodontal flap surgery – the surgical raising and replacing of surgical flaps, to enable subgingival debridement to be carried out.•
Soft tissue biopsies – the partial or complete removal of soft tissue oral lesions, for pathological investigation and diagnosis.Arguably, these surgical procedures constitute those most worrying to the patient, as bleeding and possible postoperative pain are quite likely to occur. The dental nurse has a very important role in the reassurance and monitoring of the patient during these procedures, so that the patient remains less anxious and more co-operative throughout.
As always, Health and Safety and infection control procedures must be strictly adhered to before, during and after the surgical procedure.