Principles of scaling and root planing

Introduction to scaling and root planing

Term scaling refers to the instrumentation of the crown and root surfaces of the teeth to remove plaque, calculus, and stains from these surfaces ¹. Root planing is defined as a treatment procedure designed to remove cementum or surface dentin that is rough, impregnated with calculus, or contaminated with toxins or microorganisms ². It was Albucasis who designed a set of instruments to remove calculus around 1000 years ago. He believed that removal of calculus was essential for keeping the mouth healthy. Cleaning of tooth surfaces was also recommended by Pierre Fauchard (father of modern dentistry) to cure gum diseases and he designed specific instruments for this purpose. Riggs (1882) ³, stressed upon the importance of scaling in the treatment and prevention of periodontal diseases. He stated that if tartar is deposited over the tooth surfaces, the first principle of surgery demands that it should be removed and following its removal within three days a marked improvement is noticed.

Rationale for scaling

Numerous clinical and histopathological studies have demonstrated beneficial effects of calculus removal on gingival and periodontal health ^4-10. Calculus present on enamel surface in supragingival areas can be easily removed, but calculus present in subgingival areas and interproximal areas is difficult to remove. It has been demonstrated that calculus deposited in supragingival areas has a much less physical hardness as compared to the underlying tooth structure which makes it easily removable ¹¹. However, during calculus deposition on cementum surfaces, the apatite crystals may be deposited onto the cemental surfaces as well as into the calculus matrix. It brings the two structures in an intimate contact and makes calculus removal from the cemental surfaces more difficult as compared to that from enamel surfaces ¹².

     Another factor responsible for firm cementum and calculus attachment is increased microscopic roughness of cementum surfaces facing periodontal pocket ¹³. During pocket formation, the Sharpey’s fiber ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

Rationale for root planing

As already stated, the cementum surface exposed to the periodontal pocket is rough as compared to non-exposed areas. The rough surfaces act as a reservoir for micro-organisms and hence disease progression. The resorption defects formed on the cementum during pocket formation also serve as a reservoir for the plaque which may serve as foci of re-infection. Hence, removal of these defects and achieving a clean and smooth root surface during periodontal treatment is essential ^{14, 15}. The resorption defects and roughness over the root surface have been shown to be responsible for the failure of periodontal treatment and the use of magnifying glasses and fiber optic illumination has been recommended to evaluate the root surfaces following instrumentation ¹⁶.

     Another major rationale for root planing is the removal of contaminated cementum. The endotoxins secreted by the periodontal pathogens invade the cementum surface and contaminate it. It has been shown that the normal migration of cells during periodontal healing is hindered by the presence of these toxins and a biologically acceptable root surface is required for adequate healing ¹⁷. Daly (1982) ¹⁸ demonstrated that microorganisms associated with periodontal disease penetrated the cementum till the depth of cementodentinal junction and suggested removal of all the periodontally involved cementum. However, in the same year Nakib et al. 19 demonstrated that endotoxin adhered to the tooth surface without penetration into cementum of either periodontally healthy or diseased teeth, and binding of the endotoxin to the root surface appeared to be weak. Hence, the removal of all cementum was not recommended by the authors. These findings have been supported by many other studies ^20-24. Researchers have advocated that extensive root planing is not essential for endotoxin removal from the root surface ²². Hence, while doing root planing a very thin layer of cementum needs to be removed to achieve a biologically acceptable root surface.

     Scaling and root planing creates a layer of organic and mineralized ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

Instruments used for scaling and root planing

Presently, a large number of hand instruments are available for scaling and root planing. A detailed description of these instruments is available in “Periodontal instruments”. The oldest instruments used for scaling are scalers or sickles. When adapted properly, the cutting edge of these instruments makes an angle of 90⁰ with the tooth surface. Some sickles are designed with their blade and shank in a straight line with the handle, while others (jacquette) have an angulated shank to facilitate access to various tooth surfaces. These are used for supra-gingival scaling.

     Another instrument used for scaling is the hoe. It is used to remove calculus from the root surfaces and deep pockets. The angle between the outer cutting surface and the face of the hoe is about 70⁰. The working face of hoe should make a 90⁰ angle with the root surface. The shank of hoe is slightly bowed so that it can maintain a two-point contact on a convex tooth surface. At least four different hoes are required to get access to all circumferential tooth surfaces.

      The most important instrument used for subgingival scaling and root planing is a curette. A detailed description of the design of curettes, their classification and their method of application has been discussed in “Periodontal instruments” and “Principles of instrumentation”. Area specific curettes are used for removal of calculus deposits on the root surfaces in different parts of the dentition. For root planing, an angle of 60-80⁰ is established by the curette face with the root surface and pull stroke is applied with moderate pressure. Excessive removal of cementum should be avoided from the root surface.

     Files are primarily used to remove the top of gross roughness. These are excellent for achieving initial planing of very rough surfaces. However, these may cause streaking if used for root planing. Ideally, their use should be followed by the application of curettes and sickles. As the working end of the file is small, it may be used to reach the calculus in deep, narrow pockets where curettes or hoe cannot be brought into appropriate working position.

     All the above instruments are used with a pull motion for scaling and root planing. Instruments which are used in a push motion are chisel scalers. The blade of the chisel is ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

Identification of calculus deposits

The first step in carrying out scaling and root planing is the detection of sites with calculus deposition. The areas with calculus deposition can be identified by visual examination under bright light. Both the supragingival calculus and calculus just below the gingival margin can be identified under good lighting and clean field. A jet of compressed air can be used to identify calculus deposits on the root surface facing periodontal pocket. The compressed air displaces the soft tissue away from the tooth surface, making deposits near the cervical area of root visible. Use of explorers to detect sites with calculus deposits is a common method used by clinicians. This method requires a sharp and pointed explorer or probe which is moved in the subgingival areas on the root surface and changes in tactile sensation are observed. The instrument is held in the hand with a light but stable modified pen grasp. This grasp provides maximum tactile sensation.

     The pads of the fingers perceive slight vibrations conducted through the instrument shank. The tip of the instrument is moved vertically on the root surface, making light exploratory strokes. Once calculus deposition is encountered, the tip is moved apically until the root surface is felt. Usually, the distance between the apical end of calculus and bottom of the pocket is around 0.2-1.0 mm. In the contact areas, the explorer is extended at least halfway across the surface past the contact area so that any deposits in the interproximal areas can be detected, without missing.

     The handle of the instrument should be rolled in between the thumb and fingers to detect any surface changes such as convexities or concavities encountered at line angles and interproximal ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

Clinical procedure for scaling and root planing

Scaling and root planing are the two basic procedures carried out in patients with accretions on the teeth and periodontal disease. Scaling and root planing are not separate procedures, but a component of the initial periodontal therapy of complete periodontal treatment plan. The appointments required for these procedures may vary according to the clinical presentation of the case. In patients with less calculus deposits and relatively healthy periodontium, only one appointment may be sufficient, whereas, in patients with a lot of calculus deposits and inflamed periodontal tissues, more appointments may be required for these procedures.

Supragingival scaling:

The supragingival calculus is clinically visible under good lighting and clean field. It is less tenacious and less calcified which makes it easily removable from the tooth surface. Because it is deposited above the gingival margins, there are a fewer chances of any damage to the soft tissue. The scaling instruments can be easily placed in a proper angulation because there is no hindrance from the soft tissue. The instruments used for supragingival scaling include sickles, curettes, sonic and ultrasonic power-driven scalers and to a lesser extent chisels and hoes. The instrument is held in a modified pen grasp and finger rest is established. The cutting edge of the instrument is placed to engage the apical edge of the calculus with the face of the blade making an angulation of slightly less than 90⁰ with the tooth surface. After the instrument has been stabilized; short, powerful overlapping scaling strokes are activated in the coronal direction with a pull action. It must be noted that while using the sickles, their sharp tip may lacerate the soft tissue of the gingiva and gouge the exposed root surface, so care must be taken to properly adapt the instrument to the tooth surface and carefully activating the stroke.

     Once all the visible calculus has been removed and the tooth surface is free of all the supragingival deposits, the areas just below the gingival margins should be inspected. If there is any visible calculus deposit, it should be removed using curettes or sickles (if the soft tissue is not injured). Finally, when all the surfaces of the teeth are free from calculus, polishing is done to smoothen out any surface irregularities, which may result due to instrumentation.

Subgingival scaling and root planing:

As already discussed, subgingival calculus is harder as compared to supragingival calculus and is difficult to remove due to its close adaptation to the cementum on the root surface. The subgingival instrumentation becomes more difficult due to the overlying tissue, which makes the adaptation of proper angulation of the instrument difficult. The clinician has to rely heavily on the tactile sensitivity because the vision is, most of the times, obscured by bleeding. The scaling instrument can easily extend beyond the junctional epithelium especially if the tissue is inflamed. Many clinical studies have demonstrated instruments extending farther apically than intended during subgingival instrumentation ^{29, 30}.

      During initial scaling in inflamed areas, application of local anesthesia should be avoided because the risk of overextending the instrument beyond the junctional epithelium is greatly increased due to lack of any pain response from the patient. The scaling site should be irrigated during scaling so that the calculus particle and debris are flushed out. Blowing air in the periodontal pocket during scaling is not safe as the air may pass into the connective tissue ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

     The most common instruments used by most of the clinicians for subgingival scaling and root planing are curettes. Both universal and area-specific curettes have been designed for subgingival scaling and root planing. Area-specific curettes such as Gracey curettes have been designed to reach all the surfaces of dentition as closely as possible. As already described in “Principles of instrumentation”, the instrument is held in a modified pen grasp and is stabilized by establishing a secure finger rest. An appropriate finger rest should allow keeping the lower shank of the instrument parallel to the long axis of the tooth and should allow the operator to use wrist arm motion to activate strokes (Figure 54. 2). The finger rest should be close to the working area so that appropriate instrumentation can be done. A finger rest established too far from the working area forces the clinician to separate the middle and ring finger due to which the stroke activation requires finger flexion. It adversely affects the scaling and root planing strokes and thus, the quality of the instrumentation. In certain posterior areas in the maxillary arch, opposite arch or extraoral fulcrums are required to stabilize the instrument.

     As already stated, the lower shank of the instrument is kept parallel to the long axis of the tooth. The working end of the instrument is then inserted into the periodontal pocket, with close to 0⁰ angulation and after it reaches the base of the pocket and apical end of the calculus is engaged, a working angulation between 45⁰ and 90⁰ is established. Pressure is applied laterally against the lateral wall of the tooth and a series of controlled overlapping, short and powerful pull strokes are made to dislodge calculus from the root surface. The instrument should be closely adapted to the root surface during instrumentation. The instrument ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

     The excessive lateral pressure during subgingival scaling and root planing may result in loss of tooth structure and formation of nicks and gouges. Sometimes ditches may be formed on the root surface because of excessive removal of cementum from a particular area. To avoid these problems, short, powerful scaling strokes are used initially to remove calculus and as soon as calculus and root surface roughness has been eliminated longer root planing strokes with light pressure are applied.

     The removal of calculus from the interproximal areas is difficult, especially if the contacts are wide. Scaling and root planing below the contact areas of the adjacent teeth is done by keeping the lower shank of the instrument parallel to the long axis of the tooth and extending the cutting edge as far as possible below the contact area. With lower shank parallel to the long axis of the tooth, the blade of the curette can reach the base of the pocket and instrument stroke can reach at least halfway across the proximal surface. If the lower shank is angled and tilted away from the tooth, the toe will move towards contact area and cutting edge won’t be able to engage the calculus. On the other hand, if the lower shank is tilted towards the contact area, application of scaling and root planing strokes will be hindered.

Healing after scaling and root planing

In most of the cases, immediately after scaling and root planing the epithelial attachment is severed and junctional and sulcular epithelium is partially removed ^{29, 32, 33}. If the gingival tissue is severely inflamed, the scaling instruments often extend beyond the epithelial attachment and create tears in the connective tissue. Under the microscope, strands of partially loosened epithelium and chronically inflamed connective tissue can be seen in the gingival crevice. The scaling also splits deep ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

     After 24 hours, intense mitotic activity within the epithelium can be observed and within 48 hours the entire gingival crevice is covered with epithelium. In the next 4-5 days, the formation of new epithelial attachment takes place. Depending on the extent and severity of inflammation the complete healing of the epithelium takes place within 1-2 weeks.

In one investigation done on monkeys 34, the authors observed following changes during healing after scaling,

1. The newly formed epithelial cells are derived primarily from the remaining cells of the junctional and crevicular epithelium.
2. The regeneration of the epithelium reaches its peak 1-2 days following scaling.
3. The healing of connective tissue reaches its peak 2-3 days after scaling.
4. A new epithelial attachment may be established as early as 4-5 days after scaling.

     Some less detailed studies on humans ^{6, 33} also demonstrated similar events of healing except that the time interval for various healing processes may vary. The complete healing of the epithelium may take as long as 9 months or more flowing scaling and root planing ³⁵.

     Studies have been done to investigate the re-colonization of bacteria in periodontal pocket following scaling and root planing. It has been observed that there is a significant change in bacterial ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

Changes observed after scaling and root planing

The most important change observed after scaling and root planing is the resolution of gingival inflammation due to which the gingiva attains a uniform color, gingival tissue bulk is reduced and tissue density is increased, tendency for bleeding on probing is reduced and the reduction in crevicular depth is observed. Reduction in probing depth is also a significant finding following scaling and root planing. In one study, it was observed that for pockets 4-6 mm deep, an average reduction in probing depth of 1 mm is expected following scaling and root planing and for pockets 7 mm or deeper, the expected reduction in probing depth is 2 mm ⁴². This reduction in probing depth is observed partly due to the recession in the gingival margin and partly due to gain in attachment level.

Re-evaluation after scaling and root planing

Re-evaluation is an important component of periodontal treatment and is necessary to access the effectiveness of periodontal therapy to date and to provide guidance for future treatment. A thorough evaluation of the patient after Phase I therapy is essential to determine the effectiveness of the initial treatment, to identify the elements which have served their purpose and should be continued, and which have been ineffective and should be discontinued. The periodontal re-evaluation should be performed 4 to 8 weeks after the final scaling and root planing visit 43. This much time period is sufficient for the inflammation to subside, re-establishment of the fresh dentogingival unit. Along with this, this much time is sufficient for the patient to develop an effective oral hygiene routine.

     During the re-evaluation visit, the clinician needs to perform three important tasks. Firstly, the clinician needs to assess the effectiveness of initial periodontal therapy and overall control over the disease. Secondly, the clinician can ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ……… Contents available in the book ………

Conclusion

The elimination of plaque and calculus from the tooth surfaces is the basic requirement for a successful periodontal treatment. There is enough evidence which suggests that scaling and root planing followed by adequate plaque control can dramatically improve the condition of periodontal tissues. In areas with deep pockets, surgical intervention is required to get complete access to the root surfaces so that all the calculus can be removed and effective root planing can be done. It has been well established that periodic scaling and root planing are the cornerstones of periodontal maintenance therapy following an active periodontal treatment.

References

References are available in the hard-copy of the website.

Suggested reading

Zappa U, Smith B, Simona C, Graf H, Case D, Kim W. Root substance removal by scaling and root planing. Journal of Periodontology. 1991 Dec;62(12):750-4.