FIXED PROSTHESIS AND THE PERIODONTAL
- INTRODUCTION :
The success of all prosthetic restorations depends largely on maintaining periodontal health. Indeed, these restorations are subject to mechanical requirements that must not conflict with biological requirements.
The objective of this course is to highlight the importance of prior periodontal assessment, which allows determining whether or not pre-prosthetic periodontal treatment is indicated. This course also emphasizes the need for a rigorous clinical approach during each stage of prosthetic construction, respecting the periodontium.
- ANATOMO-PHYSIOLOGICAL REMINDERS :
21) The periodontium: it is made up of:
- Gum
- alveolar bone
- periodontal disease
- cement
22) Biological space: extends from the bottom of the sulcus to the bony crest = approximately 2 mm
FIXED PROSTHESIS AND THE PERIODONTAL
3) PURPOSE OF THE FIXED PROSTHESIS:
- Restoration of destroyed crowns: to ensure protection and stimulation of supporting tissues by recreating relationships between teeth
- Replacement of missing teeth: to allow a harmonious distribution of occlusal forces
- Restoration of a harmonious occlusal plane: by prosthetic remodeling of the occlusal surfaces which eliminates interferences and prematurities as harmful parafunctions for the periodontium
- Restoration of a disturbed vertical dimension
- Contention: by distributing the loads, relieves the pillars weakened by occlusal overloads
- Aesthetics and function: once designed, it must ensure the sustainability of a physiological and stable periodontal state
4) PERIODONTAL EVALUATION :
The assessment of periodontal health is an essential prerequisite. It does not only consist of determining whether the periodontium is healthy or diseased, but also whether it is able to resist attacks during the various prosthetic stages.
4-1) Oral hygiene should be assessed during the initial examination, taught and verified during the different therapeutic phases.
The long-term prognosis of all prosthetic treatments is directly linked to the quality of plaque control. Thus, any prosthesis will be contraindicated if plaque control proves insufficient .
4.2) PERIODONTAL CONDITION:
- Periodontal health assessment:
-Appreciation of biological space
FIXED PROSTHESIS AND THE PERIODONTAL
– Evaluation of the superficial periodontium:
– Height and thickness of attached gum:
Maynard and Wilson propose a height of keratinized gingiva of 5 mm, including at least 3 mm of attached gingiva, considered as a safety zone.
5) Interest of pre-prosthetic treatment: it is the set of clinical steps carried out before the prosthetic design, the aim of which is to obtain a favorable ground to receive a fixed prosthesis :
– Healthy or stabilized periodontium
– Edentulous segments showing no pathology
– Stable and balanced occlusion: without prematurities or interferences.
– Rigorous oral hygiene.
Pre-prosthetic treatment uses associated therapies:
- endodontics,
- restorative dentistry,
- orthodontics,
- periodontics, surgery.
- temporary prosthesis.
6) OBJECTIVES OF DECORTICATION:
6-1) Occlusal objective
- homothetic reduction of the dental substance for a prosthetic reconstruction anatomically and physiologically integrable into the stomatognathic system and sufficient to have sufficient thickness of metal and adequate contours
6-2) Periodontal objective
- creation of a cervical limit representing the junction limit with solution of continuity of the prosthetic edge with the cut dental crown
- creation of the interproximal contact point for better protection of the interdental papilla.
7) REQUIREMENTS THAT A JOINT PROSTHESIS MUST MEET :
7- 1) Hygienic imperative :
7.1.1) The anchor crown must not have a pronounced domed shape making self-cleaning difficult, nor a rough surface susceptible to bacterial plaque (a).
7.1.2) The bridge intermediary must provide sufficient space with the edentulous ridge giving free access to brushing(b).
(a) 
7. 2) Occluso-articular imperative:
A homothetic reduction of the dental tissue will allow sufficient thickness of the metal to be accommodated.
FIXED PROSTHESIS AND THE PERIODONTAL
- The occlusal morphology must fit into the patient’s occlusal scheme in order to avoid overloads that generate constraints.
7. 3) Periodontal imperative :
7.3.1) shape and location of the cervical limit of the supporting tooth:
It must have a perfect fit with the edge of the prosthetic device.
- It must represent a base for prosthetic anchoring .
7. 3.2) Shapes and volume of prosthetic crown :
The prosthetic crown must have a point of contact with the adjacent tooth that meets anatomical and physiological criteria in order to accommodate and protect the interdental papilla and ensure the stability of the dental arch and food retention.
The ideal curve of the vestibular and lingual surfaces must protect the marginal gingiva from an overly aggressive action of food while allowing stimulation by food without creating recessed regions leading to difficult hygiene, which implies a copy on the neighboring or contralateral tooth.
The bridge or pontic intermediary, while ensuring the restoration of the continuity of the dental arch and the adjustment of the occlusion, must meet two contradictory imperatives that should be reconciled, namely:
- have the best possible aesthetic appearance
- to best protect the fibromucosa of the edentulous ridge from inflammation
To do this, you would have to follow certain rules, namely:
- the intermediate element must, to avoid the accumulation of food deposits, be in contact with the fibromucosa of the ridge by the smallest possible surface area
- the junction between the different elements of the bridge must provide widely open embrasures allowing easy cleaning of these regions
7.3.3) The temporary prosthesis:
A temporary prosthesis is essential for
- ensure healing of the marginal periodontium damaged by cervical margin preparations and access techniques
- stabilize the prepared tooth
- ensure pulp protection
It is recommended to adapt the provisionals while leaving in the sulcus a retraction wire used during preparation or impression, which will thus avoid any aggression to the attachment system.
FIXED PROSTHESIS AND THE PERIODONTAL
- 7-3-4) The imprint:
In very aesthetic areas and particularly if the gum is thin, it may be advisable to take the impression 2 to 3 weeks after the last touch-up of the preparations to ensure the stability of the marginal tissues.
Access to the limits:
The technique of choice uses gingival deflection using a double cord:
the cords used are, unlike those used for the preparations,
knitted cords easier to place in the sulcus thanks to their more
low density.
7.3.4) Sealing :
- temporary sealing: it is short-term, it allows us to control the contour of the preparation and its marginal periodontium
- the definitive sealing: must be carried out once the marginal periodontium has healed,
any excess must be removed and a solution of continuity of the prosthetic piece with the tooth must be perceived with the probe
FIXED PROSTHESIS AND THE PERIODONTAL
8) CONCLUSION:
The success of a joint prosthesis depends not only on mechanical and aesthetic imperatives , but also on periodontal ones.
Periodontal health and dental restorations are closely linked; in fact, a prosthesis should only be undertaken in the presence of healthy periodontium.
On the other hand, the prosthesis must ensure the sustainability of this state of health.
Periodontal integration results in stability of the periodontium around the prosthetic device. This stability depends both on the extent of trauma related to the prosthetic procedure and the existing periodontal structures.
Hence the importance of a prior periodontal assessment as well as a rigorous clinical approach during each stage of prosthetic construction.
FIXED PROSTHESIS AND THE PERIODONTAL
Deep cavities may require root canal treatment.
Interdental brushes effectively clean between teeth.
Misaligned teeth can cause chewing problems.
Untreated dental infections can spread to other parts of the body.
Whitening trays are used for gradual results.
Cracked teeth can be repaired with composite resins.
Proper hydration helps maintain a healthy mouth.