1: Diagnosis and Treatment Planning in Restorative Dentistry

Diagnosis and Treatment Planning in Restorative Dentistry

Periodontal Diagnosis

A. Fiorini

In restorative dentistry the planning of treatment cannot be based on mere examination of the single tooth to be restored, but should encompass assessment of the oral cavity as a whole. It must thus outline a global treatment plan that takes both hard and soft tissues into account and considers the tooth as a functional unit composed of several structures (Figure 1-1).

By global treatment plan we mean a set of decisions and operating procedures undertaken in order to draft the definitive treatment plan. Informed consent for diagnostic and therapeutic procedures should be obtained at the first appointment, along with the patient’s medical history. Emergencies should be treated at an early stage, sometimes even before the treatment plan is drawn up. Clinical examination and full mouth series radiographs are the two other important factors required for an accurate general picture of the case, in order to draft the temporary treatment plan. The periodontal checkup, which consists of probing and assessment of the periodontal indexes (bleeding and plaque indexes) is crucial and permits reevaluation of the case and hence drafting of the definitive treatment plan.

Notes on the Anatomy and Histology of the Dental Functional Unit

The key aspect of periodontal diagnosis is identification of local and systemic risk factors that can affect the anatomic structures and thus jeopardize the stability and even the survival of the tooth. The following structures are involved in the process (Figure 1-2): radicular cementum, periodontal ligament, and alveolar bone in the strict sense of the term. In 1961 Gargiulo, Wentz, and Orban described the concept of biologic width as a space of about 2 mm composed of the connective tissue attachment and the epithelial attachment, an inviolable space for dental and periodontal health (Figure 1-3).

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Figure 1-3 Biologic width.

An important anatomic variable is the arrangement of the cemento-enamel junction. When the cementum does not reach the enamel (Figure 1-4, A) and thus exposes a small amount of dentin, the risk of attack by bacterial, chemical, or mechanical agents is greater. In this case gingival recessions and erosion of the exposed radicular dentin can frequently be observed (Figure 1-5).

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Figure 1-5 Gingival recessions and root exposures. The subject has an interrupted cemento-enamel junction (see Figure 1-4, A), which favors the onset of soft-tissue alterations with more severe lesions on the left side (because the patient is right handed, brushing is stronger on the left side of the mouth).

Diagnosis

There are three key points to consider in periodontology—diagnosis, infection control, and treatment—all of which will be discussed later in the book.

Medical History

Not only is medical history an important component when obtaining the patient’s general data and clinical history, but it permits identification of local and systemic factors or diseases that can alter the equilibrium of the oral cavity (Figures 1-6 to 1-11)—for example, stress, smoking, poor oral hygiene, drug abuse, and iatrogenic injuries.

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Figure 1-11 A full mouth series shows no periodontal disease and the presence of faulty restorations that prevent correct periodontal probing (see Figure 1-10). During professional oral hygiene maneuvers it is necessary to remove overhangs to enable soft-tissue reconditioning.

Periodontal Probing

Periodontal probing was—and still is—an important factor in determining the presence and severity of periodontal disease (Figure 1-12). From a diagnostic standpoint, periodontal probing and assessment of the following three parameters are crucial.

1. Pocket depth: (PPD—probing pocket depth) Distance measured from the tip of the probe (located at the apex of the gingival sulcus) to the gingival margin. Inflamed tissues are much looser than the healthy ones. Consequently the probe penetrates more deeply with respect to the actual depth of the periodontal pocket (clinical parameter). Probing performed before the causal therapy will present greater depths than is actually the case; the bottom of the pocket is not a reference point for assessing the loss of periodontal attachment (histologic parameter).

2. Attachment level: (PAL—probing attachment level) Distance between the cemento-enamel junction and the lowermost point of the gingival sulcus. It is clear that attachment level and pocket depth will exhibit identical values when the gingival margin and cemento-enamel junction correspond.

3. Bleeding on probing: (BOP—bleeding on probing) An inflammation index that alone does not provide information regarding the aggressive behavior of the disease.

In 1979 Maynard and Wilson demonstrated that when the biologic width is violated during restoration, the result is comparable to periodontal disease. Figure 1-13 shows that faulty restoration causes resorption of the bony ridge, as in the case of periodontal disease.

Periodontal probing should follow certain criteria (pressure, probing sites), bearing in mind that measurements are affected by operator-dependent variables (pressure) and independent variables (type of probe, status of the soft tissues) (Figures 1-14 to 1-16).

Initial preparation (causal therapy) paired with concomitant removal of the causes of inflammation (calculus and overhanging restorations) improves the conditions of the soft tissues, which will be firmer at the next probing. This explains why, even if there are pockets, reevaluation can yield a lower probing score than what was assessed at the initial examination, even in cases of no attachment gain (Figures 1-17 and 1-18).

Please note that in reporting the patient’s probing scores, in addition to the aforementioned parameters it is also a good idea to include information regarding tooth mobility and status of the tissues (recessions).

On the periodontal chart the results of probing at the furcation areas will be described as degree 1, 2, or 3 (see Figure 1-21). An effective system for quickly viewing the status of the furcation areas is to draw a symbol on the chart beside the tooth (Figures 1-19 to 1-21).

In case of abscess (Figure 1-22), probing values are not significant, because a probe inserted in this area will penetrate past the pocket depth and will not provide any useful information. In case of marginal gingivitis (Figure 1-23) a pocket depth of 4 to 5 mm might revert to normal values (less than 3 mm) after the cause of inflammation is removed, owing to reduced tissue edema.

A different scenario occurs when inflammation is caused by a vertical fracture; in this case the periodontal probe will penetrate deeply only at the fracture site because of absence of the ligament and not because of tissue laxity (Figure 1-24).

Such a finding is pathognomonic of a vertical fracture, even in the absence of inflammation and/or radiographic evidence.

Radiographs

A full mouth series of radiographs is indispensable for drawing up a correct treatment plan. With respect to the panoramic radiograph this makes it possible to assess if the disease affects only a few teeth or if it is a diffuse form (Figure 1-25). The subsequent treatment plan varies according to the cause of the disease. Generalized defects demand complete treatment in conjunction with causal therapy, whereas treatment of localized defects involves only the affected teeth. To complete the full mouth series it is useful to take two bitewings (Figure 1-26). The number of radiographs and their distribution may change—for example, 16 radiographs, distributed as follows, can be taken even if teeth are missing (Figures 1-27 to 1-36):

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Figure 1-26 Bitewing radiographs.

Radiographs

Radiographs

Radiographs

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Figure 1-35 Periodontal pseudopockets. The full mouth series of the same patient shown in Figure 1-34 reveals the absence of periodontal disease. The 6- to 7-mm probing depth is not related to a lesion but to the different heights of the interproximal peaks of bone, caused by the mesial inclination of the tooth. The treatment is not periodontal but surgical (extraction of the third molars) and orthodontic (uprighting of the second molars), followed by prosthetic or implant treatment.

Laboratory Testing

Laboratory tests may be useful for establishing the etiologic diagnosis of the periodontal disease and its treatment. They can be easily performed with sterile endodontic paper points (Figure 1-37) introduced into the active periodontal pockets and then placed in proper containers to be sent to the microbiology laboratory for testing (Figure 1-38).

The European Workshop on Periodontology (2002) established the chief causative agents responsible for periodontal disease. The same bacterial agents are also found in the oral mucosa, and their presence is a sign of aggressiveness of the disease. In fact, the Third European Workshop on Periodontology (1999) recognized the terms “aggressive periodontitis” and “chronic periodontitis.”

Treatment

Once the various diagnostic procedures and initial preparation have been completed, it will be possible to establish treatment procedures:

The therapeutic goals are elimination and control of local and systemic causative factors in order to restore oral microflora compatible with periodontal health. Overhanging restorations alter the microflora because they prevent proper cleaning of the area, thus allowing the inflammation to persist.

Etiologic Phase

Reestablishment of healthy oral flora, treatment of periodontal defects, and restoration of the periodontal and dental morphology are the prerequisites for restoring tooth function and morphology and maintaining proper oral hygiene at home.

When there is thin tissue, proper oral hygiene helps preserve the structures and teeth (Figure 1-39).

In these types of patients the equilibrium of the dentoperiodontal unit is very delicate, and if oral hygiene maneuvers are done incorrectly or are overly aggressive, recessions or changes in the gingival scalloped profile are common findings. The status of the hard tissues (caries), gingiva (recessions), and morphology (phenotype) guide therapeutic decisions. For instance, sometimes placement of ceramic veneers can avoid involvement of the marginal periodontium (Figures 1-40 through 1-43). Patients with a thick and scalloped phenotype (Figure 1-44) have less chance of developing gingival recessions and show a higher resistance to mastication and hygiene-maneuver traumas. Despite the presence of inflammation, this situation can be reversed through proper oral hygiene.

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Figure 1-40 Initial status.

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Figure 1-42 Cosmetic mockup.

Reparative Phase

Causal therapy is a fundamental step in periodontal treatment and should be carried out before any therapeutic intervention.

After “periodontal health” has been reestablished, it should be maintained by means of periodic recalls for professional oral hygiene sessions, which will vary depending on the dental and periodontal status and level of home oral hygiene.

Good periodontal health makes it possible to switch from the temporary treatment plan to the definitive one. Periodontal surgery applied to restorative dentistry mainly concerns crown-lengthening procedures necessitated by fractures or subgingival caries.

Clinical Crown Lengthening

Clinical crown lengthening is a surgical procedure that permits more apical repositioning of the periodontal attachment for restoration with respect to the biologic width. Caries or cusp fractures are classified into three different clinical patterns:

Comparison of Two Similar Clinical Cases (Figures 1-49 to 1-55)

Case 1

Caries Diagnosis

The School of Dental Medicine of the University of Geneva defines restorative dentistry as the sum of clinical procedures aimed at preserving natural teeth and their function in order to maintain both the oral and systemic health of the patient.

The goals of restorative dentistry are as follows:

Therefore restorative dentistry—like any other medical branch—encompasses a diagnostic phase, followed by a therapeutic one, and then a maintenance and checkup phase. Diagnosis can be defined as the process that leads to disease identification through analysis of the patient’s signs, symptoms, medical history, and laboratory results.

From an etiologic standpoint, caries is an infectious disease, meaning that it is caused by a microbial factor, which represents the causal agent. It is common knowledge that it can be transmitted to experimental animals (Figure 1-56). It is characterized by progressive destruction of the hard tissues of the tooth, through both decalcification of the mineral component and proteolysis of the organic component, which result in cavitation.

The 1960 Keyes diagram (Figure 1-57) shows the interaction of the three factors that are decisive for the onset of the caries lesion:

Caries Classification

The literature has an array of classifications that illustrate the caries process. They can be anatomopathologic, topographic, symptomatologic, clinical, and radiologic. In purely operational terms, the main classifications are clinical and radiologic.

Anatomopathologic Classification

Enamel Caries

From an anatomopathologic standpoint, enamel caries on smooth surfaces appears macroscopically as an opaque whitish spot that can develop into cavitation or become pigmented (Figures 1-58 and 1-59).

On the level of pits and fissures (Figure 1-60) the affected enamel is brown in appearance (dark areas), and the development toward cavitation and subsequent involvement of the underlying dentin is often difficult to assess clinically.

The microscopic evaluation of carious lesions on smooth enamel surfaces exhibits a triangular pattern (conical section) with the apex pointing toward the dentin (Figure 1-61).

With pits, the lesion has always a triangular shape, but in this case the apex is directed outward, whereas the base of demineralization faces the dentinal substrate (Figure 1-62).

In both situations, especially in the case of initial lesions, the outer surface is seemingly intact, making it difficult for the clinician to arrive at an accurate assessment of the real involvement of the underlying tissues (Figure 1-63).

Dentin Caries

Macroscopically, dentin caries is traditionally and didactically classified into two forms:

From a clinical and operational standpoint, the distinction between the two dentin caries subtypes does not affect the therapeutic approach to the lesions, which requires complete removal of the pathologic tissue during cavity preparation.

Microscopically, dentin caries has a distinctive conical shape, with the apex of the lesion directed toward the pulp (see Figures 1-61 to 1-63). Some authors divide carious progression into three distinct phases:

Carlier’s schematic diagram (1954) shows the five characteristic zones of dentin caries, distinguishing—in a crown-apical direction—a “disorganized” outer layer followed by a “soft” dentin one, an area of bacterial invasion, and a deeper “clear” area with initial obliteration of dentinal tubuli, which is followed by the last layer, consisting of “hard” dentin, indicating pulp reactivity (Figure 1-66).

Therefore dentin caries formation is a dynamic pathologic process in which regressive alteration phases are alternated with reactive phenomena.

Topographic Classification

There are two types of topographic classification systems pertaining to carious lesions, the first and best known being that of Black.

The Black classification system makes an initial distinction between coronal and radicular caries. Coronal caries is then further divided into five groups:

In addition to the five traditional classes, Class VI was added subsequently, covering cavities on the top of the cusps of posterior teeth and carious lesions of the incisal margin of anterior teeth.

The second most recent topographic classification was proposed by Mount and Hume in 1998; here lesions are classified according to site and size.

Based on location, caries lesions are classified as follows:

Together with the site, the size of the lesion is also taken into account:

Symptomatologic Classification

Incipient caries of the enamel exhibits the following characteristics:

Patients with interproximal lesions may report discomfort from a foreign-body sensation, stagnation, or periodontal irritation (possible bleeding of the gingival papilla).

Established caries of the dentin shows marked symptoms that guide diagnosis because of the characteristics of dentinal pain, which has the following characteristics:

Clinical Classification

The clinical classification according to professors Baume and Holtz of the School of Dental Medicine of the University of Geneva is based on the extent of caries penetration, and it consists of five degrees of severity.

Jan 1, 2015 | Posted by in Dental Materials | Comments Off on 1: Diagnosis and Treatment Planning in Restorative Dentistry
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