Dental prosthesis loosening

Here is another manifestation indicating occlusal issues: the frequent loosening of a prosthetic piece (dental crown or bridge).
As a matter of fact, irrespective of the retention means and the lamination of the piece, if our realization is well designed, its position will be perfectly reinforced by the stabilization provided simultaneously by the proximal contacts and by the occlusal contacts. After each closing, the prosthetic piece will be in the most favorable position with its support.
But some interferences in laterality or propulsion may still occur, which may detach the prosthetic piece from its support. The dentist should always check all parameters and proceed to final cementing only when the stabilization of the prosthesis is ensured.
If it’s not the case, dental migrations, periodontal injuries or even worse, coronal or  root  fractures may occur. If all these elements resist, then temporo-mandibular disorders may develop. This aspect justifies a temporary cementing of the prosthetic parts and, if possible, an immediate detection of this type of disruption, to correct it before definitive cementing.
Occlusal disorders may cause various diseases, which will be discussed later in this blog. These pathologies are as follows:

dental diseases (dental migrations, tooth wear, mylolysis, loosening, pulp hyperemia)
periodontal diseases
joint diseases
muscular diseases
diseases in relation with the individual’s overall balance (headaches, dizziness, backache, eye problems, tonic postural system problems, psychological diseases  associated with craniomandibular disorders)

Mylolysis

Mylolysis has long been considered as the expression of mechanical or chemical wear of a certain part of the tooth.
This part being most of the time at the neck of the tooth, it had been frequently said that excessive, or inadequate tooth brushing was causing this loss of substance, leading to hypersensitivity.
As a result of a suggestion made by Mario de Stefanis in 1971, we undertook to find out if there was a connection between mylolysis and dental occlusion. A study carried out on 658 cases of mylolysis allowed us to highlight a causal relationship between mylolysis (and their hypersensitivity) and the occlusion of the affected tooth.
In this study we described  the “occlusal trauma positive sign”: this corresponds to a hypersensitivity case were the sensitivity will totally disappear, or be largely reduced, in the 48 hours following a single occlusal adjustment of the affected tooth. That work has been taken up by  many teams, and our hypotheses were confirmed.
The enamel structure  is a cohesive bond of enamel rods and occlusal strains can distort it. The less cohesive bonds of enamel will then be eliminated of the surface of the tooth through excessive mechanical brushing, triggered  by a frequently described perception of irritation.
This alteration is found near constantly in parafunctional patients. Recent works show that our assumption is true, and match with well-supported evidence.
Occlusal disorders may cause various diseases, which will be discussed later in this blog. These pathologies are as follows:

dental diseases (dental migration, tooth wear, mylolysis, loosening, pulp hyperemia)
periodontal diseases
joint diseases
muscular diseases
diseases in relation with the individual’s overall balance (headaches, dizziness, backache, eye problems, tonic postural system problems, psychological diseases  associated with craniomandibular disorders)

Tooth wear

Just as dental migrations, tooth wear is the result of a chewing disorder. Tooth wear and tooth factures are typical signs caused by occlusal disorders.
If the surfaces of teeth show excessive wear, it is important to investigate the cause(s) and perform corrective actions to stop the phenomenon.
A normal tooth wear shouldn’t be compensated or disturbed by any intervention. But a good practitioner should check regularly the intra and inter connections between the arches: if they’re losing their cohesion, this could lead to the disorganization of the whole manducatory system. As soon as possible, an intervention should try to restore their previous balance. But if the whole manducatory system shows a regular wear on all teeth, in a uniform way, then it may be appropriate to carefully restore all teeth.
Fractures of the incisal edges of teeth are also the expression of mandibular kinematics causing interferences between the facial surfaces of mandibular teeth and the lingual and palatal surfaces of maxillary teeth. In such cases, most of the time, those fractures are caused by a discomfort in the  posterior maxillary mandibular contacts. The patient just tries to compensate this discomfort by seeking for a better perception of contact with its front teeth, which is generally easier to obtain. Teeth grinding in this position will unavoidably entail either a regular wear with polished incisal edges, or a crackled look resulting from a regular wear in relation with  the quality of hard tissues of the teeth.
Occlusal disorders may cause various diseases, which will be discussed in this blog. These pathologies are as follows:

dental diseases (dental migration, tooth wear, mylolysis, loosening, pulp hyperemia)
periodontal diseases
joint diseases
muscular diseases
diseases in relation with the individual’s overall balance (headaches, dizziness, backache, eye problems, tonic […]

Dental migrations

In the various dental diseases that can be caused by occlusal disorders, one of the most early recognizable signs involves the position of the teeth.
This observation is made difficult when the teeth are misaligned, but it is particularly instructive when the dental arch is perfectly aligned. It is frequent to observe a perfectly aligned arch loosing its order as a consequence of a dental restoration, a prosthesis or a filling which doesn’t properly rebuild the contact between teeth.
A strain can also move the tooth and break the continuity of  the proximal contacts. This is a phenomenon that may happen a while after an ordinary correction of the arches. More globalized dental migrations are often the consequence of a more important strain, leading to serious disorders in the manducatory system.
Therefore attention must be paid to regularly check the dental positions and ascertain that the occlusion plays its part as a holding key.
Periodontal diseases with weakening of the connective tissues also cause migrations which wouldn’t have occured otherwise. When this happens, the phenomenon’s causes must be investigated and its amplitude must be evaluated.
Occlusal disorders may cause various diseases, which will be discussed in this blog. These pathologies are as follows:

dental diseases (dental migration, tooth wear, mylolysis, loosening, pulp hyperemia)
periodontal diseases
joint diseases
muscular diseases
diseases in relation with the individual’s overall balance (headaches, dizziness, backache, eye problems, tonic postural system problems, psychological diseases  associated with craniomandibular disorders)

 

Foreword

It is now obvious that occlusal therapy is a direct, unquestionable link between all dental disciplines which intervene in the functioning of the manducatory, or chewing system.
The progress made towards harmonious teeth reconstruction, either by new materials or by the advent of implant techniques, leads us to think that the mastering of occlusion is an essential requirement.
Furthermore, the connections existing between the chewing system and the other systems participating in  each individual’s global balance are highlighted everyday. The manducatory tract is a system which parts are constantly participating in several vital functions, in addition to chewing. It is essential in dental practice to maintain a good occlusion or to recreate it, if it has been lost. In this respect, the contribution of occlusal therapy is critical and should not be considered as secondary or incidental.
These reasons seemed enough to me to take the risk of trying to synthesize the subject and share my knowledge with you, while keeping a constant clinical approach.
 

Dr Jean-Pierre Toubol.

Dental surgeon – Doctor of dental sciences – Post Graduate University Of southern California.

Creator of the first university degree of occlusal therapy.
Founding member of National French College of Occlusal Therapy.
Past president of National College of Occlusal Therapy.
Member of european licensed experts.
Past president of the International Academy of Computerized Dentistry (Houston, Texas USA).