Periodontics. Fernando Suarez

gingiva usually presents a coral pink coloration, while mucosa is darker and redder (see Fig 2-3).Schiller’s iodine testOral mucosa can be stained with an iodine solution because of the glycogen distribution, while KG is iodine-negative.¹⁶Roll techniqueOral mucosa is movable while AG/KG is bonded to tooth surface and bone. A clear demarcation (MGJ) would appear when rolling from movable mucosa to AG/KG.

      BLEEDING ON PROBING

      BOP is another important parameter to record during periodontal examination, and it indicates evidence of gingival inflammation. A prospective study by Lang and colleagues evaluated the prognostic value of sites with BOP and the risk for periodontal breakdown of at least 2 mm of attachment loss during periodontal maintenance therapy.¹⁸ The results showed that only a 30% probability of future attachment loss may be predicted for sites repeatedly positive for BOP (Table 2-2).¹⁸ Further calculations confirmed that frequent BOP for prediction of future attachment loss yields a specificity of 88%, and the continuous absence of BOP has a positive predictive value of 98%.¹⁹ Therefore, it is of paramount importance to understand that BOP alone does not represent a good positive predictor for disease progression⁷; instead, studies have shown that absence of BOP is a more reliable parameter to indicate periodontal stability.¹⁹ BOP is also sensitive to the forces applied with the probe^2,19; therefore, Lang et al suggested a probing force of 25 g (0.25 N) when recording BOP, as heavier pressures (> 25 g) might traumatize the gingival tissue and provoke bleeding.¹⁹ In conclusion, the presence of BOP has low sensitivity and high specificity with respect to the development of additional attachment loss. For clinicians to monitor patients’ periodontal stability over time in daily practice, the absence of BOP at 25 g is a reliable indicator for periodontal stability with a negative predictive value of 98%.^7,18,19

TABLE 2-2 Positive predictive values for loss of attachment of ≥ 2 mm in 2 years in sites that bled on probing 0, 1, 2, 3, or 4 times out of 4 maintenance visits¹⁸

BOP incidence	Sites with loss of attachment > 2 mm
4/4	30%
3/4	14%
2/4	6%
1/4	3%
0/4	1.5%

      FURCATION INVOLVEMENT

      The furcation is the anatomical area of a multirooted tooth from where the roots diverge and form bifurcation (two-rooted tooth) or trifurcation (three-rooted tooth).² Furcation involvement or furcation invasion describes the pathologic resorption of bone within a furcation area^1,2,20 (Fig 2-4). The Nabers furcation probe is widely used and suited for detection and examination of furcation involvement.^2,20 The extent and configuration of furcation involvement can be characterized by anatomical factors including but not limited to presence of cervical enamel projections, enamel pearls, root trunk distance, tooth surface concavities, and the extent of root separation. The following summarizes the furcation entrances of multirooted teeth to aid in detection of furcation involvement²⁰:

      Fig 2-4 Furcation entrance on a mandibular first molar.

       Maxillary premolar:Furcation involvement can be detected from the mesial or distal surface; the entrance is located at the apical third of the root and/or approximately 8 mm below the CEJ.

       Maxillary molars:Buccal entrance: Centered mesiodistally.Mesial entrance: Two-thirds of the buccolingual width toward the palatal aspect, easier to approach from mesiopalatal aspect.Distal entrance: Furcation entrance is centered buccolingually and can be examined from either the buccal or palatal aspect.

       Mandibular molars:Buccal entrance: Centered mesiodistally at the buccal surface.Lingual entrance: Centered mesiodistally at the lingual surface.

      The amount of furcation involvement of a multirooted tooth can be registered depending on the horizontal and vertical amount of bony destruction into the furcation area.^20–22 Many systems have been proposed for classifying furcation involvement.² Hamp’s classification is one of the most commonly used for furcation destruction.²² A brief review of three systems is presented in the following sections.^2,20–23

      Horizontal destruction

      Glickman (1958) divided furcation involvement into 4 grades²¹:

       Grade I: Pocket formation into the flute but intact interradicular bone. Incipient lesion.

       Grade II: Loss of interradicular bone and pocket formation of varying depths into the furcation area but not completely through to the opposite side of the tooth.

       Grade III: Through-and-through lesion.

       Grade IV: Same as Grade III with through-and-through lesion with gingival recession, rendering the furcation area clearly visible on clinical examination.

      Hamp et al (1975) proposed three levels of furcation involvement²² (Fig 2-5):

      Fig 2-5 Different degrees of furcation involvement.

       Degree I: Horizontal loss of periodontal tissue support < 3 mm.

       Degree II: Horizontal loss > 3 mm, but not passing the total width of the furcation.

       Degree III: Horizontal through-and-through destruction.

      Vertical destruction

      Tarnow and Fletcher (1985) proposed the following classification based on the vertical bone loss around furcations. It is encouraged to supplement each category of horizontal destruction with a subclass based on the vertical bone resorption.²³

       Subclass A: 0 to 3 mm probeable depth.

       Subclass B: 4 to 6 mm probeable depth.

       Subclass C: ≥ 7 mm probeable depth.

      MOBILITY

      The definition of tooth mobility is the movement of a tooth in its socket resulting from an applied force.¹ Increase in tooth mobility is often a sign of periodontal breakdown and/or presence of excessive occlusal forces.¹ Tooth mobility is detected by using the ends of two instruments (eg, mirror handle) on either side of the tooth and alternately applying forces.² The most commonly used clinical index for tooth mobility is the Miller Index; using this index, mobility can be scored as the following^2,24:

       Class 0: Normal (physiologic) movement when force is applied. It has been defined as movement up to 0.2 mm horizontally and 0.02 mm axially.

       Class I: First distinguishable sign of movement greater than “normal” or “physiologic.”

       Class II: Movement of the crown up to 1 mm in any direction (buccolingual or mesiodistal).

       Class III: Movement of the crown more than 1 mm in any direction (buccolingual or mesiodistal) and/or vertical depression (apicocoronal) or rotation of the crown in its socket.

      Radiographic Interpretation

      Clinical periodontal examination provides information with regard to PDs, recession defects, AG/KG, and more; however, it cannot reveal the status of the alveolar bone. The alveolar bone is another critical aspect to take into consideration to accurately diagnose different periodontal diseases and conditions.² Dental radiographs are the most commonly used noninvasive method of examining alveolar bone levels. Other