Diagnosis and Treatment Planning in Restorative Dentistry
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).
Figure 1-1 Algorithm of the global treatment plan.
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.
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).
Figure 1-2 Histology and diagram of the periodontal ligament depicting the fibers that connect the tooth to the bone by means of radicular cement. The fibers that go from the bony ridge to the gum surface are those that give the gum its stippled appearance, in proportion to their number.
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).
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).
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.
Figure 1-6 Owing to severe neurologic degeneration, the patient takes antiepileptic drugs and has motor difficulties that prevent proper oral hygiene. In this case, maintenance therapy with frequent professional oral cleaning recalls is advisable. More aggressive therapies are not recommended, as maintenance by the patient is difficult and it is impossible to eliminate the cause of the disease.
Figure 1-7 Drug abuse and addiction in general cause behaviors and pathologies that can negatively influence the effectiveness of therapy, as it is impossible to establish a healthy physician-patient relationship and the patient is uncooperative during the therapeutic phases.
Figure 1-8 Young patient with poor or no oral hygiene. The clinical examination reveals the presence of a mass of composite material, placed above the calculus in order to try to keep the central lower incisors in place. In this case the treatment is incorrect, although it was performed on an emergency basis; scaling should precede any intervention.
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 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.
Figure 1-12 Radiographic image of periodontal probing.
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.
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).
Figure 1-14 The Williams probe (A) is the most easily readable, as it is very thin and easy to use because the probing depth reference marks are at 1, 2, 3, 5, 7, 8, 9, and 10 mm. Therefore it is preferable over flatter and very wide probes, which may complicate probing (C), or others with colored marks at 3, 6, 9, and 12 mm (B).
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).
Figure 1-17 Periodontal probing sites. The case with six probing sites (two mesial, two distal, one buccal, and one lingual) is compatible with proper operating standards. The probe should slip into the sulcus during transition from one site to the other and slide along the tooth wall to detect any roughness or abnormalities.
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).
Figure 1-19 Probing sites at the furcation areas, which should be reported on the periodontal chart. V, degree 1 (probing 1 mm); Ø, degree 2 (probing 1 to 3 mm); , degree 3 (probing more than 3 mm; completely passes through the furcation).
Figure 1-20 A curved (Naber) probe makes it possible to reach into the furcation area. A, Probing of the vestibular bifurcation of the maxillary molar. B, Probing of the bifurcation between distal and palatine roots (this assessment is usually performed on the buccal side). C, Probing of the bifurcation between palatine and mesial roots (this assessment is usually performed on the lingual side). D, Probing of the bifurcation of the first maxillary premolar.
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).
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):
Figure 1-25 Full mouth series of 16 radiographs.
Figure 1-26 Bitewing radiographs.
Figure 1-27 Severe periodontal disease caused by the presence of a foreign body (toothpick) that remained in place for over 2 weeks, which caused inflammation with radiologic findings of demineralization and deep probing depth not associated with periodontal disease.
Figure 1-30 Overhang. The presence of overhanging restorations that favor plaque accumulation creates periodontal situations that can lead to bone loss; prompt removal of the faulty restoration and its replacement with correct treatment limits the loss of periodontal support.
Figure 1-32 A, Incorrect prosthetic works and pulp chamber perforations can create lesions that are not always detectable with the periodontal probe, which cannot be positioned correctly because of the overcontoured crown. B, The periodontal probe cannot be positioned correctly because of perforation of the pulp chamber by a pin.
Figure 1-33 Chronic periodontitis. The restorative treatment of the distal tooth caries is pointless without a comprehensive assessment. Simple periodontal probing combined with radiographs allows detection of a very serious periodontal lesion. The tooth must be extracted.
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 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).
Figure 1-38 Report of laboratory tests.
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.”
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.
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.
Figure 1-39 Thin and scalloped gingival phenotype.
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.
Figure 1-44 Thick and scarcely scalloped gingival phenotype.
Figure 1-40 Initial status.
Figure 1-41 Causal therapy and polishing.
Figure 1-42 Cosmetic mockup.
Figure 1-43 Cementation of feldspathic ceramic veneers.
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 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:
Figure 1-45 Subcrestal tooth fracture. Restoration will be possible only after osteoplasty for repositioning the bony ridge apically. A, The incision reflects the future scalloped aspect of the gumline. B, The bone surrounding the tooth has been remodeled. C, The apical repositioning of the edge of the palatal flap can be noted. Restoration can be performed during surgery or postponed for a later session.
Figure 1-46 Caries extending below the crest. A and B, This is a more complex case that requires a multidisciplinary approach. The tooth has to be treated endodontically after interim and temporary restoration to facilitate endodontic treatment. The cervical step of the tooth, too close to the bone crest, requires a clinical crown-lengthening procedure, the outcome of which would compromise the esthetic results because of the modified scalloped edge of the gum. C, To achieve better esthetic results the periodontal surgery must be preceded by an extrusive orthodontic treatment. D, The outcome of the extrusion movement is clearly illustrated in the radiograph.
Figure 1-47 A and B, Clinical crown lengthening allows recontouring of the bone margin. C, Apical repositioning of the gingiva without altering the scalloped profile. D, The checkup 6 years later shows that the results have been maintained.
Figure 1-48 Poorly contoured restoration. A, During the visit an impediment to periodontal probing, caused by a poorly contoured buccal restoration, was noted. B, The exploratory flap allows assessment of its extent. C, Correct restoration performed intraoperatively. D, Apical repositioning of the flap.
Figure 1-50 A, Despite the clinical appearance and the proximity of the cervical step to the bone crest, it is possible to achieve good isolation of the operative field using a rubber dam and insulation material. B, Positioning of the metal matrix band. C, The restoration is made of amalgam, and the 1-year checkup shows the restored function of the tooth.
Figure 1-52 A, The endodontic access is performed through the old restoration, keeping its marginal ridge. B, The restoration is performed with an amalgam patch. C, The restoration is rebuilt and tooth function is restored.
Figure 1-53 A, Four years later a new caries prevented the execution of another restoration procedure. B through D, The restoration must follow surgical clinical crown lengthening, and a concomitant core buildup procedure. E, A temporary restoration is positioned during the tissue maturation period and will be later replaced by the definitive one. F, The final outcome can be seen at the radiographic checkup 10 years after surgery.
Figure 1-55 A, Isolation of the field with a rubber dam and dental matrix band. B and C, Restoration of the tooth by means of a direct composite technique, and occlusal check. D, The correct positioning of the contact point with respect to the biologic width is crucial for optimum healing of the tissues.
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.
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 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.
Figure 1-59 A, Interproximal caries with marked enamel irregularities and pigmentation. B, After removal of the affected and decalcified enamel the involvement of the underlying dentin becomes apparent. C, Cavity preparation completed. D, Final adhesive restoration.
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.
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).
• A “chronic” form or arrested caries, usually found in adult teeth, which progresses slowly. It has a blackish-brown color, and its consistency is harder and drier compared with the active carious lesions seen in young teeth (Figure 1-65).
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).
Figure 1-66 Carlier diagram of 1954. In a carious lesion five successive layers can be distinguished microscopically from the enamel toward the pulp: A, disorganized zone; B, softened zone; C, invasion zone; D, transparent zone; E, hard zone. (From Nespoulous and Carlier, 1954.)
• Class I—Morphologic depression, pits and fissures of posterior teeth (Figure 1-67), pits and foramina ceca of anterior teeth (Figure 1-68)
Figure 1-73 Initial enamel caries of the occlusal grooves.
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.