The aim of initial periodontal therapy is to remove pathogenic microorganisms and their byproducts (e.g. calculus, lipopolysaccharides) from around affected teeth, in order to promote cessation of periodontal inflammation and to halt progression of disease. This process renders the tooth/root surfaces compatible with periodontal health. Typically this involves the use of scaling, root debridement and the provision of oral hygiene instructions. In order to produce biologically acceptable tooth surfaces plaque and calculus are removed from the tooth and root surfaces and the underlying cementum is planed off, as its surface will have been contaminated by microbial byproducts (e.g. the lipopolysaccharides). Since it is thought that only the surface of the cementum becomes ‘contaminated’ as a consequence of microbial activity, it is not necessary to remove the entire layer of cementum while planing the roots. Nonetheless, a smooth root surface should be produced following planing. A smooth root surface should, theoretically, lead to less accumulation of plaque biofilm, calculus and a decreased chance of reinfection, and from a clinical perspective, is the only way that the root-debridement can be assessed as having been done properly.
The presence of plaque can be identified by direct inspection or after staining with disclosing solution, which stains plaque that has been allowed to form on teeth for longer than 2 days.
The presence of supragingival calculus can be identified by visual inspection. As regards the presence of calculus that has formed below the gingival margins (subgingival calculus), this is often detected using tactile senses, with the aid of a periodontal probe or a periodontal explorer. The periodontal explorer can be used for the detection of supragingival and subgingival calculus present in shallow pockets. The periodontal probe can be used for the detection of calculus in both shallow and deep pockets. This makes it the instrument of choice for the detection of calculus and, as alluded to above, under clinical conditions this instrument can provide tactile information indicating whether or not the root surface has been planed as well as possible.
Intraoral radiographs such as periapical and bitewing films are also valuable aids in the detection of interproximal calculus, especially when the deposits are subgingival.
The instruments used for the removal of plaque and calculus are called scalers and curettes. They can be manual or ultrasonic. Supragingival calculus and plaque are removed with the aid of sickle scalers, while subgingival calculus and plaque are removed with the aid of curettes.
Scalers have 2 working edges, which converge toward a sharp tip. The tip should not be used for subgingival instrumentation, as it may gouge the root surface, thereby increasing the root’s roughness. It may also traumatize the soft tissue lining the periodontal pocket or crevice.
Curettes have rounded tips that can be used during instrumentation in the subgingival environment, as they’re less likely to damage the surrounding soft-tissues. Curettes have either one or two working edges and rounded tips that can be sharpened and also used for removal of plaque and calculus.
Prior to use, the cutting edges of the instruments are checked and, if necessary, sharpened. A cutting edge is deemed to be sharp if it does not reflect light. The instrument is held firmly, in an area with good visibility, so that the inner part of the working end is parallel to the floor. The sharpening stone is first cleaned of metal particles that may have been produced during previous sharpening and then moistened with water. The stone is then adapted to the cutting edge in the 2 o’clock position and it is moved lightly upward towards the cutting edge. This light upward motion is repeated until the cutting edge of the instrument no longer reflects light. No downward sharpening strokes are used with this sharpening method. Depending on the amount and tenacity of calculus deposits, instruments often require repeated sharpening during a single scaling appointment.
Supragingival calculus is removed by engaging the apical end of the deposit with a scaler and then moving the scaler coronally. A fair amount of force is often required to dislodge large calculus deposits, which often extend between several teeth.
Subgingival calculus is removed as follows: first, its presence and location are identified with the aid of the periodontal probe. The appropriate curette is chosen and then adapted to the root, apical to the deposit of calculus. There are various curette types and sizes that can be used, depending on the anatomical features of the tooth and root surface, as well as the depth of the pockets being treated. The cutting edge is engaged and the curette is moved across the root surface with short, controlled, overlapping, coronally-directed strokes until the entire deposit of calculus has been removed. While engaging the working edge of the curette, its terminal shank should be oriented parallel to the long axis of the tooth being instrumented.
After a cycle of root planing is completed, it is necessary to determine the extent of removal of calculus that was accomplished. And, as an indirect indicator of the efficiency of debridement, the probe is used to determine the amount of calculus still present by assessing the smoothness of the root surface. If residual calculus is still detected (generally meaning that the root still feels rough) the root planing procedure is continued until calculus cannot be detected any longer and the root surface feels smooth. After that, the next tooth is examined for the presence of plaque and calculus and cleaned as required.
Curettes are also used for the removal of plaque from pockets in which there is no calculus. In such cases, the roots are instrumented using only light pressure, so as to prevent the removal of excessive amounts of cementum and dentin, which can lead to dentinal hypersensitivity.
Ultrasonic instruments are used for the removal of tenacious supragingival and subgingival calculus. The power and water output of ultrasonic scalers can be adjusted individually so that the generation of undue heat is avoided. The manual and ultrasonic scalers are used alternatingly until complete calculus removal and smooth root surfaces are achieved. As with the use of manual sickle scalers, care is taken to avoid touching the root surfaces with the point of the ultrasonic scaler. Only light pressure is applied, as calculus removal is accomplished by the high frequency vibration of the ultrasonic tips.
Patients who are overly sensitive or who have deep subgingival deposits may require some form of anesthesia/analgesia. In this regard, it must be understood that patients can feel pain during scaling and root planing as a consequence of having either hypersensitive root surfaces, inflamed/tender subgingival tissues, or both. When the patient is not overly sensitive, adequate anaesthesia can be established with the use of a topically applied anesthetic (e.g. Ora-Q® or Cetacaine®). In other cases, the patient’s tissues and teeth might be extremely sensitive, at least during the initial stages of treatment. In those cases, injected local anaesthetic might be needed either by way of local infiltration or a nerve block.
Six to eight weeks after the initial therapy, a process that may take one or several appointments, the patient’s periodontal condition is re-evaluated according to the parameters used during the initial examination. The results of the re-evaluation are compared to the findings obtained at the initial examination. If necessary, oral hygiene instructions are reinforced or altered at this appointment.
As a result of decreased inflammation and reduced swelling of the gingival tissues, previously inaccessible residual calculus deposits may become accessible. If such deposits are detected at the re-evaluation appointment, they are removed.
Depending on the results of the re-evaluation, the post-initial treatment diagnosis is established. It will serve as baseline for determining guidelines for future surgical and/or non-surgical periodontal treatment or for the development of an individualized maintenance program.
Special thanks to Drs. Abbassali Hassanali, Vanessa Mendes and Quyen Su.