Evaluation of periodontal attachment loss

Periodontal probing is the primary diagnostic technique for determining pocket depth, involving measuring from the marginal gingiva to the depth of the pocket. Ongoing assessment of clinical attachment level or probing depth is considered the benchmark for documenting changes in periodontal status.

Assessment of tooth mobility

Microperiodontometer (Korber K.H 1963) ^[12] Mobility of teeth with non-working interferences can be detected with a microperiodontometer. A force of 500g was applied 3 times on the facial and lingual displacements were recorded

Piezoelectric transducer (Oka H., 1998) ^[13] A device that utilizes the piezoelectric effect to detect and measure changes in acceleration, pressure, strain, temperature, or force by converting these mechanical energies into an electrical charge.

Dental holographic interferometry (Wedendal P.R.,1974) ^[14] This is a non-contact and non-destructive method that utilizes a Q-switched double-pulsed ruby laser. This technique provides detailed information and its documentation is enhanced by a special photographic method

Non-contact vibration device, as described by Yamane M. in 2008, is an electromagnetic vibrating device that utilizes an alternating sine wave to generate force without physically contacting the tooth. ^[15]

Resonance frequency analysis (RFA) (Meredith in 1994) ^[16] A test to assess implant stability by measuring the frequency of implant oscillation inside the bone.

Laser vibrometer (Castellini P.,1999) ^[17] A small hammer and a load cell were utilized to apply dynamic loads on teeth, measuring the forces. Subsequently, a Laser Doppler vibrometer was used to measure tooth displacement. This method is easy to use and enables versatile non-contact measurements with high accuracy and sensitivity (< 0.1 mm/sec).

Periotest®M, developed by Medizintechnik Gulden in Modautal, Germany, is an electronic wireless device utilized for evaluating tooth mobility and the osseointegration of implants. Its functioning involves measuring the response to a consistent impact applied to the tooth surface's center. The device calculates the duration of contact per impact by employing an electrically controlled rod that strikes the tooth and then recoils. Variations in this contact duration may suggest structural alterations in the periodontal bone or soft tissue as a result of periodontal disease. ^[18]

Implomates, created by Bio Tech One Inc. in Taipei, Taiwan, is a device that employs an electromagnetic field to drive a metal rod for percussing the tooth. The device records the vibrations produced using a microphone with a resolution of 50 Hz. ^[19]

Osstell IDX- The Osstell IDX, developed by Osstell AB in Gothenburg, Sweden, is a non-contact device designed for measuring implant stability (osseointegration) through OSTELL employs Resonance Frequency Analysis (RFA) with resonance frequencies between 3000 and 8500 Hz to determine the implant stability factor on a scale of 0 to 100. It is a non-invasive and non-destructive method, consisting of a transducer, a computer analysis unit, and an excitation source. ^[20] Designed to enhance patient comfort and reproducibility in measuring implant stability, although it is optimized for assessing osseointegration rather than traditional tooth mobility. To minimize variations arising from test position and device operating conditions, tooth mobility tests using a non-contact vibration technique should be conducted. ^[21]

Examination of plaque and calculus

DetecTar probe is designed to detect subgingival calculus by analyzing optical signals on root surfaces and distinguishing spectro-optical variances between calculus and tooth surfaces. Subgingival calculus produces a unique spectral signature when exposed to a specific light wavelength, attributed to absorption, reflection, and diffraction. These signals are captured by a fiber optic and converted into an electric signal for computer analysis. The DetecTar probe tip is similar in shape and dimension (0.45 mm diameter) to conventional periodontal probes. Additionally, the system can serve as a portable cordless hand-piece with a curved periodontal probe that includes millimeter scale markings for measuring clinical attachment level and probing depth. ^[4]

Perioscopy, developed by Zest Dental Solutions in Carlsbad, CA, USA, involves using a miniature periodontal endoscope to visualize the root surface within the periodontal pocket. This technique provides magnifications of up to 48×, assisting in the identification of residual calculus spots during examinations.

Diagnodent, is a pen-like probe that emits a harmless, painless laser beam onto the tooth to detect autofluorescent signs of calculus lesions. Uses a range of values for relative calculus detection to measure fluorescence intensities, which are then shown on an electronic screen. ^[2]

PerioScan is capable of identifying calculus deposits and offers a treatment mode for traditional ultrasonic debridement with adjustable power levels. It concurrently shows blue light and emits an acoustic signal on both the handpiece and screen to aid in diagnosis when the ultrasonic tip detects calculus on the tooth surface. Conversely, Key Laser 3 is designed for calculus detection and removal in a feedback-controlled manner. This automated device features a 655-nm In:Ga:As diode laser for calculus detection and a 2940-nm solid-state erbium-doped yttrium aluminum garnet (Er:YAG) laser for calculus removal. Some studies suggest that there are no statistically significant differences between feedback-controlled laser debridement and ultrasonic treatment. The Perioscan and Key Laser offer diagnostic and treatment modes that can be used continuously on the same tooth surface without changing instruments. However, these devices have limitations. Improvements are needed in the specificity of calculus detection, particularly in reducing false detections, where irregularities on the root surface are incorrectly identified as calculus. Sensor-integrated probes have been used to measure parameters not typically assessed in clinical examinations, such as temperature and sulfide concentration. ^[22]

Evaluation of gingival inflammation

Measurement of volatile sulfur components

Periodontal diseases, particularly plaque-induced gingivitis, are linked to sulfide byproducts. Various tools are available for detecting sulfides, including the Halimeter, the Oral Chroma and the Breathtron. These tools are designed to detect halitosis and are not used for the diagnosis of periodontal disease. The Diamond Probe/Perio 2000 System is designed to offer real-time monitoring of gram-negative bacteria and sulfide levels in the gingival sulcus and periodontal pockets. This system utilizes a microscale sensor integrated into modified Michigan O sulfide periodontal probes to measure clinical attachment level (CAL), probing depth (PD), bleeding on probing (BOP), and sulfide levels. Upon detection of sulfides in the gingival crevicular fluid (GCF) by the sensor-integrated probe tip, the system provides information using a four-color light bar, an audible tone, and the actual sulfide level.

Conventional radiographs

From CEJ to the crest of alveolars, special but weak sensitivity and bone loss can be estimated.

Limitations

Change in the projection geometry.

Differences in the contrast and density between them.

Masked by another anatomic structure.

Subtraction radiography ^[26] Used to enhance the diagnostic information obtained from radiographs by removing superimposed images that are not useful for diagnosis. It provides a quantitative and qualitative view of minor variations in bone density. Here, two radiographic images are taken, one before and one after a certain treatment or time interval. The images are then digitally subtracted from each other, highlighting any changes that have occurred between the two images. In the resulting image, areas of bone loss appear darker, while areas of bone growth appear lighter, allowing for a more precise detection of changes in bone density.

Digital radiography: Using a sensor to capture radiographic images revolutionized dental imaging. Trophy introduced the first digital radiographic images of teeth through the RVG Radiographic Imaging System in 1987. ^[27] This innovation brought several advantages: a) Elimination of chemical processing: Digital radiography eliminates the need for traditional film processing chemicals, reducing environmental impact and costs. b) Increased efficiency and speed: Digital images can be viewed immediately after capture, allowing for quicker diagnosis and treatment planning. c) Improved diagnostics: Digital radiographs can be enhanced and manipulated to improve diagnostic accuracy, such as adjusting brightness and contrast or zooming in on specific areas of interest. d) Computerized storage: Digital radiographs can be stored electronically, saving physical storage space and enabling easy retrieval for comparison over time or for referral. e) Reduced radiation exposure: Digital radiography typically requires less radiation exposure compared to traditional film radiography, enhancing patient safety.

Computer-Assisted Densitometric Image Analysis (CADIA) is a radiographic method introduced by Urs Bragger et al in 1988. This technique allows for the quantification of changes by measuring the radiographic density in a predetermined region between baseline and subsequent subtraction radiographs. The camera used in CADIA measures the light passing through the radiograph, and the signal captured by the camera is converted into a grayscale image. Advantages of CADIA include its ability to measure the quantitative change of bone density and its higher sensitivity, reproducibility, and accuracy compared to subtraction imaging.

Computed Tomography (CT) is a specialized radiographic technique that enables the visualization of specific planes or slices of interest. CT offers several advantages over conventional radiography, including the elimination of superimposition of images of structures in superficial or deep areas, the ability to distinguish differences between tissues of varying physical density due to its high contrast resolution, and the capability for multiplanar imaging, allowing multiple scans of a patient to be interpreted as images in axial, coronal, and sagittal planes, depending on the diagnostic requirements. However, CT also has some disadvantages. It requires specialized equipment and setting, involves higher radiation exposure compared to conventional radiography, and may produce ring artifacts from metallic restorations that can affect image diagnostics.

Cone-beam Computed Tomography (CBCT): A newer technology for acquiring 3D images of oral structures. It is cheaper than CT, less bulky, and produces a smaller dose of X-radiation. ^[26]

Advantages

Creates a complete 3D reconstruction.

Allows limited X-radiation exposure through beam collimation.

Reduces image artifacts.

Computer-Based Thermal Imaging: Compares the rewarming rate of normal and inflamed human gingiva to aid in the measurement of gingival temperature. It is a noninvasive method provided by infrared thermography.

Tuned Aperture Computed Radiography: Tuned aperture computed tomography (TACT) is superior in detecting signals that were not appropriately visualized by other available imaging modalities. It offers increased sensitivity and specificity for a number of diagnostic tasks, high resolution, lower dose after image processing, and no artifacts associated with CT. ^[27]

Ultrasonography: Used in periodontology to measure alveolar crest height and assess periodontal bone morphology. However, it may not be accurate or reproducible, especially in difficult-to-access areas. ^[28] Palou et al. (1987) were also able to assess periodontal bone morphology using ultrasonic imaging. They concluded that measurements of the alveolar bone topography with ultrasonic probes are not accurate and reproducible, especially in difficult access areas. ^[29] Lost et al. (1988) were able to determine the width of the periodontal ligament, using dimensional in prepared pig jaws. A reliable image of the alveolar crest of the gingival ligament tissues and the entrance of the periodontal space could be obtained by ultrasound. ^[30]

Micro CT used to quantify histomorphometry of alveolar bone. ^[31] It allows for high-resolution imaging of specimens at the micron level and enables computer-aided reorientation following scanning, ensuring almost exact alignment.

Bone Scanning or Radionuclide Imaging: Detects new bone growth or breakdown areas using nuclear scans. It is used to assess damage to the alveolar bones and monitor conditions affecting the periodontium. ^[32]

SimPlant: Computer program for assessing dental implant sites. It uses CT data combined with advanced computer graphics to assess bone volume, height, and quality, select appropriate implant length, and visualize the lower alveolar canal clearly. ^[33]

Intraoral Scanners: Project an illumination source to the object for a scan and send photomorphological data to a connecting computer system to generate 3D models in digital form. ^[34], ^[35] Zhang et al. 2021 indicated that gingival volume changes could be measured with an intraocular scanner after therapy. Other parameters such as Probing depth, bleeding index and keratinized gingival width have been positively correlated with the results. ^[36] The Key benefits include shortens the time needed for diagnosis, provides relief from pain and discomfort to patients, enables real-time scanning and visualization and allows for quick diagnosis and communication without potential deformation of results. ^[37] Commercially available intraoral scanners include the TRIOS, the iTero Element, CEREC Omnicam and the Emerald.

Disadvantages

Predicting disease activity at the site can be challenging.

Selecting the biomarker to evaluate is challenging because no biomarker has been proven to be an exact indicator of disease activity.

PerioGard and PocketWatch are products designed to measure the levels of aspartate aminotransferase (AST), which is an abundant enzyme found in human gingival epithelial cells and gingival fibroblasts. Elevated AST levels in gingival crevicular fluid after cell death may indicate significant gingival tissue destruction, as large amounts of AST are released from the cells' cytoplasm into the GCF. The activity of AST in both products is evaluated by comparing the color of the collected GCF from patients with that of the controlled AST-positive group, based on the enzymatic catalysis reaction.

The PerioSafe and ImplantSafe tests are qualitative evaluations of aMMP-8 levels in oral rinse and gingival crevicular fluid respectively. These tests use an automated digital device called Oralyzer, which can quantify the amount of aMMP8 in ng/mL units within five minutes. Recent reports indicate that a device equipped with an MMP-8 assay kit is beneficial for distinguishing between active and inactive sites through rapid and straightforward analysis. It is also useful for detecting asymptomatic, ongoing periodontitis before clinical and radiographic signs become apparent. ^[40], ^[41], ^[42]

SillHa and Salivary Multi Testan, assess a range of saliva indicators (including blood, leukocytes, and proteins) linked to gingival health. Both products comprise test strip kits and an automated wavelength reflectometry device. This device detects color changes on the test strips in about five minutes.

Electronic Taste Chips - These are chemically sensitized bead microreactors integrated into a lab-on-a-chip system. They have the ability to distinguish between healthy individuals and those with periodontal disease based on their CRP level. Furthermore, they can concurrently monitor saliva inflammation biomarkers. The system analyzes analytes such as acids, bases, electrolytes, and proteins in the solution phase. ^[43]

Oral Fluid NanoSensor Test- In 2012, Dr. David Wong created OFNASET, an automated device designed for the detection of oral cancer using saliva. The Oral Fluid NanoSensor Test (OFNASET) detects various salivary proteins and nucleic acids using an electrochemical method. It is capable of identifying four salivary mRNA biomarkers (IL-8, ODZ, SAT and IL-1b) and two salivary proteomic biomarkers (Thioredoxin and IL-8) present in saliva.

Integrated Microfluidic Platform for Oral Diagnostics (IMPOD) assists in rapidly quantifying salivary biomarkers in small 10 ml volumes within 3 to 10 minutes. This includes the rapid assessment of levels of the collagen-cleaving enzyme MMP-8 in saliva from individuals, both healthy and with periodontal disease.

Periocheck- In US, Periocheck has received approval from the Food and Drug Administration. It is the quickest chairside test in GCF for neutral proteases like elastases, proteinases, and collagenases. Elevated levels of these enzymes in gingival crevicular fluid (GCF) are observed during the development of gingivitis and at sites with existing periodontitis. ^[44]

IAI Pado Test 4.5 used to identify four types of periodontal pathogens: Aa, Pg, Tannerella Forsythia, and T. denticola. This test utilizes oligonucleotide probes that specifically target the 16S rRNA gene, responsible for encoding the ribosomal RNA subunit of bacterial ribosomes, through a process called DNA hybridization.

Omnigene, a nucleic acid technology genomic probe that utilizes genetic engineering to create species-specific DNA probe tests for eight periodontal pathogens, using DNA hybridization.

Evalusite (kodak), a membrane-based enzyme immunoassay used to detect three dental pathogens, available on the market.In this assay, the antigen is linked with a membrane-bound antibody to form an immunocomplex, which is then detected using a colorimetric reaction. ^[44]

PerioScan, a diagnostic test kit that employs the BANA (N-benzoyl-DL-arginine-2-naphthylamide) hydrolysis reaction to detect bacterial trypsin-like proteases in dental plaque. It detects the presence of three periodontal pathogens in subgingival plaque (T. denticola, P. gingivalis, and B. forsythus). The BANA test was developed by Dr. Walter Loesche and colleagues at the University of Michigan. Among the 60 bacterial species in the subgingival microbiota, only these three bacteria possess a trypsin-like enzyme that hydrolyzes the synthetic peptide benzoyl-DL-arginine-naphthylamide. The test involves a plastic strip with two separate reagent matrices attached. The lower white reagent matrix is impregnated with N-benzoyl-DL-arginine-B-napthylamide, onto which subgingival plaque samples are applied. Following a 5-minute incubation at 55℃, the upper buff reagent matrix reacts with one of the hydrolytic products of the enzyme reaction, using a chromogenic diazo reagent, resulting in a permanent blue color. The intensity of this blue color in the upper buff matrix determines the strength of the reaction, indicating whether it is positive or weak. ^[45]

Toxicity Prescreening Assay detects the presence of bacteria indirectly by identifying two markers of gingival infection: bacterial toxins and proteins. The test is associated with the extent of inflammation and the advancement of the destructive process. As the concentration of these toxins increases, a change in the color intensity scale, based on metabolic activity, determines whether the periodontal disease is active or inactive. ^[46]