Radiographic assessment of the peri-implant site.

While peri-implant mucositis relies solely on clinical parameters, radiological assessment becomes indispensable for diagnosing peri-implantitis. Intraoral radiography, with its simplicity of application, low radiation exposure, and adequate representation of peri-implant structures, stands out as the standard of care for both immediate and follow-up assessments. Standardization by custom-made radiologic splints allows for excellent comparability with previous images and allows for the determination of even small changes in contour and density of the peri-implant bone. Furthermore, other radiographic modalities like panoramic radiography and cone beam computed tomography (CBCT) may provide useful features for specific patients and clinical cases while also showing innate limitations. Beyond the assessment of the marginal peri-implant bone level as the crucial parameter of clinical relevance, radiologic assessment may reveal various other findings related to the prosthetic restoration itself, the precision of its fit to the implant, and the peri-implant soft and hard tissues. Since such findings can be crucial for the assessment of peri-implant health and the implants' prognosis, a systematic diagnostic evaluation pathway for a thorough assessment is recommended to extract all relevant information from radiologic imaging. This article also provides an overview of the clinical and chronological indications for different imaging modalities in peri-implant issues.

Guided endodontics versus conventional access cavity preparation: an ex vivo comparative study of substance loss.

BACKGROUND: To compare the outcomes of conventional access cavity preparation (CONV) versus guided endodontics (GE) for access cavity preparation in anterior teeth with pulp canal calcification (PCC) regarding root canal detection, substance loss, procedural time, and need for additional radiographs. METHODS: Extracted, sound human teeth with PCC (n = 108) were matched in pairs, divided into two groups and used to produce 18 models. An independent endodontist and a general dentist performed access cavity preparation under simulated clinical conditions on nine models each (54 teeth). The endodontist used the conventional technique and the general dentist GE. Time needed to access the root canals and the number of additional radiographs were recorded. Pre- and postoperative cone-beam computed tomography scans were obtained to measure substance loss. Statistical significance was tested by examining the overlap of 95% confidence intervals (CIs) between the groups. RESULTS: All root canals were successfully accessed by both methods. There were no significant differences in substance loss (CI: CONV 15.9-29.6 mm3 vs. GE 17.6-27.5mm3) or procedural time (CI: CONV 163.3-248.5 s vs. GE 231.9-326.8 s). However, 31 additional radiographs were required for GE compared to none for CONV. CONCLUSIONS: For access cavity preparation in teeth with PCC, both CONV by a specialist and GE by a general dentist produce good results in terms of substance loss and time requirements.

Accuracy of a dynamic navigation system for dental implantation with two different workflows and intraoral markers compared to static-guided implant surgery: An in-vitro study.

PURPOSE: To investigate the accuracy of a miniaturized dynamic navigation system with intraoral markers and two different workflows for dental implantation and to compare with static computer-assisted implant surgery (sCAIS) surgery. MATERIALS AND METHODS: Two operators performed a total of 270 implant insertions in polyurethane mandibular models under simulated clinical conditions. Implants were placed after CBCT-based virtual planning in three different groups: two workflows utilizing dynamic computer-assisted implant surgery (dCAIS; DG1: marker in CBCT; DG2: 3D-printed marker) and the others with sCAIS (TG: template guided). Postoperative surface scans were matched to the planning data and allowed an evaluation of the angular and spatial deviation between the planned and the actually achieved implant position. Descriptive statistics were followed by a Mixed Model Analysis to determine the influence of the operator, the method, and operating area on different accuracy parameters and the random effect of the model number. RESULTS: The mean angular deviation ranged from 2.26° (DG1) to 2.96° (TG). The mean 3D deviation at the implant's tip ranged from 1.08 mm (TG) to 1.51 mm (DG2) and at the implant's base from 0.69 mm (TG) to 1.49 mm (DG2). The operator showed no significant influence on the accuracy. The method showed significant influence on singular parameters and the operating area on all spatial accuracy parameters. CONCLUSIONS: Dynamic navigation systems with intraoral markers enable accurate implant positioning, which is comparable to the static-guided implant surgery. 3D-printed markers provide less accurate results compared to prefabricated markers, attached before CBCT scan.

Evaluation of five methods to identify composite restorations in human teeth on a forensic purpose-an ex vivo comparative study.

The use of tooth-colored composite resin materials in dentistry is increasing. As composite restorations appear similar to the natural tooth structure, their detection is becoming more challenging. The aim of this study was to compare five diagnostic methods for detection of dental restorations and to create reliable postmortem dental records for forensic purposes. A conventional examination method without a direct light source (CONV), with a dental loupe light (DL), Galilean loupes with a direct light source (GDL), a fluorescence-inducing device (FIT), and intraoral radiographs (RX) were compared. Dentists specializing in conservative dentistry or oral surgery and dentistry students participated. Regarding sensitivity, specificity, positive predictive value, and negative predictive value, FIT and RX showed significantly higher results than CONV, DL, and GDL. RX and FIT showed comparable results in identifying composite restorations but depending on their location. The combination of both methods may lead to even better results. In conclusion fluorescence-inducing devices show good results in identifying composite restorations and therefore should be considered as a standard tool in forensic examinations. Another advantage is their small size, low cost, and mobility. Good illumination and magnification devices are recommended to enhance performance during conventional examinations. Involving dentists specialized in conservative dentistry could contribute to dental identification.

Effect of field of view (FOV) positioning and shielding on radiation dose in paediatric CBCT.

OBJECTIVE: To investigate the effect of two different large field of view (FOV) positions in the vertical dimension and shielding (thyroid collar and eyeglasses) on the effective dose and the local doses of various sites of the craniofacial complex. METHODS: Organ doses and effective doses were calculated based on the measured doses using 27 pairs of thermoluminescent dosemeters in a paediatric tissue-equivalent of a 10-year-old anthropomorphic phantom. The large FOV of the 3D Accuitomo F170 CBCT scanner was used to image parts of the craniofacial complex. Six protocols were performed: (A) cranial position without shielding; (B) cranial position with shielding; (C) caudal position without shielding; (D) caudal position with shielding, (E) similar to C with 3600 rotation and (F) similar to D with 360° rotation. Measurements were obtained in duplicate, and the relative δ value (%) was applied to compare the average doses between the protocols. RESULTS: Changing the FOV position from cranial to caudal without using shielding resulted in an increase of the effective dose of 18.8%. Use of shielding in the caudal position reduced the dose by 31.6%. Local absorbed dose of the thyroid had the most relevant impact on calculation of the effective dose, followed by oesophagus, bone marrow and bone surfaces, especially when comparing the different protocols. CONCLUSIONS: Application of shielding devices for thyroid in combination with a most caudal positioning of FOV led to the lowest local absorbed doses as well as the effective dose in a child phantom model.

Impact of CBCT image quality on the confidence of furcation measurements.

BACKGROUND: To investigate the impact of scanning parameter in cone-beam computed tomography (CBCT) images on accuracy and confidence with measurements of furcation involvement (FI) in maxillary molars. MATERIAL AND METHODS: Six half cadaver heads with present maxillary molars (n = 10) were available. CBCT scans with the fixed-parameter field of view (4 × 4 cm, 12 × 17 cm) amperage and voltage (4 mA, 90 kV) and with varying scan modes (SM), that is images/scan (IS), voxel sizes (VZ) and rotation (R), were performed using one CBCT apparatus. The images were analysed by two calibrated investigators. Horizontal FI's were measured in mm or a "through and through" destruction (FI degree III) was recorded. Each rater scored the FI measurements performed in each scan as "confident" or as "not confident". Data were statistically analysed using chi-square tests. RESULTS: The agreement between CBCT FI measurements and intra-surgical FI measurements varied according to SM (SM HiSp 180°, 0.08: kappa 0.538, CI; 95%: 0.362-0.714; SM Std. 360°, 0.25: kappa 0.698, CI; 95%: 0.534-0.861). The number of measurements scored as "confident" varied according to SM (SM Std. 360°, 0.08:52 out of 60 measurements; SM Std. 360°, 0.25:16 out of 60 measurements; p < .001). CONCLUSIONS: SM of CBCT significantly affect the confidence with FI measurements in maxillary molars.

Role of ambient light in the detection of contrast elements in digital dental radiography.

OBJECTIVE: This study aimed to evaluate the effect of different ambient light levels on observer detection of small contrast differences in a contrast phantom by using a high-end liquid crystal display (LCD) monitor. STUDY DESIGN: An aluminum step wedge was converted into a contrast phantom by the addition of bore holes. Radiographic images of the contrast elements were presented to 20 observers. Images were displayed in random order under different ambient light levels (0, 50, 200, and 500 lux) twice, and the observers had to determine if contrast elements were visible. Sensitivity and specificity were determined to calculate areas under receiver operating characteristic curves and Friedmann's test was applied to evaluate the influence of the ambient light level on observer performance. RESULTS: Mean AZ values were moderate for each ambient light level at 0.715, 0.793, 0.764, and 0.722 for 0, 50, 200, and 500 lux, respectively. The influence of the ambient light level on observer performance was not statistically significant (P > .05). CONCLUSIONS: There was no significant influence of ambient light between 0 and 500 lux on observer ability to detect small contrast details displayed on a high-end LCD monitor.

Influence of Three-dimensional Imaging on Implant Treatment Planning: Implant Diameter and Length.

AIM: To investigate the influence of the radiographic modalities panoramic radiography (PR) and cone beam computed tomography (CBCT) on selection of implant length and diameter. MATERIALS AND METHODS: Potential implant sites (59 sites, 40 patients) with available PRs and CBCTs were selected from the databases of two University dental schools. Six experienced clinicians were asked to select the appropriate implant length and diameter based on PR and CBCT. Results were compared with the actual surgical procedure and intra- /interrater agreement was calculated using Cohen's kappa. RESULTS: On average, greater implant length was more often planned based on PR (24.2 vs 8.8% with CBCT), while wider implants were generally more frequently planned based on CBCTs (19.9 vs 29.7% with PR). Implant treatment planning based on PR and on CBCT images was equal in 50 to 67%. Compared with the actual surgery, CBCT revealed a higher agreement (46% for implant length), while for PR, 34.4% equal implant length was observed. CONCLUSION: The radiographic modality used for implant treatment planning affects implant selection. CLINICAL SIGNIFICANCE: The CBCT scans are advantageous for choosing the appropriate implant dimension. Caution should be exercised when selecting implant length planned from PR.

Implant treatment planning regarding augmentation procedures: panoramic radiographs vs. cone beam computed tomography images.

OBJECTIVES: To evaluate the impact of cone beam computed tomography (CBCT) imaging on treatment planning regarding augmentation procedures for implant placement. MATERIAL AND METHODS: Panoramic radiographs and CBCT images of 40 patients requesting single-tooth implants in 59 sites were retrospectively analyzed by six specialists in implantology, and treatment planning was performed. Therapeutic recommendations were compared with the surgical protocol performed initially. RESULTS: Bone height estimation from panoramic radiographs yielded to higher measures and greater variability compared to CBCT. The suggested treatment plan for lateral and vertical augmentation procedures based on CBCT or panoramic radiographs coincided for 55-72% of the cases. A trend to a more invasive augmentation procedure was seen when planning was based on CBCT. Panoramic radiography revealed 57-63% (lateral) vs. 67% (vertical augmentation) congruent plans in agreement with surgery. Among the dissenting sites, there was a trend toward less invasive planning for lateral augmentation with panoramic radiographs, while vertical augmentation requirements were more frequently more invasive when based on CBCT. CONCLUSIONS: Vertical augmentation requirements can be adequately determined from panoramic radiographs. In difficult cases with a deficient lateral alveolar bone, the augmentation schedule may better be evaluated from CBCT to avoid underestimation, which occurs more frequently when based on panoramic radiographs only. However, overall, radiographic interpretation and diagnostic thinking accuracy seem to be mainly depending on the opinion of observers.

SADMFR Guidelines for the Use of Cone-Beam Computed Tomography/Digital Volume Tomography.

In 2011, the first consensus conference on guidelines for the use of cone-beam computed tomography (CBCT) was convened by the Swiss Society of Dentomaxillofacial Radiology (SGDMFR). This conference covered topics of oral and maxillofacial surgery, temporomandibular joint dysfunctions and disorders, and orthodontics. In 2014, a second consensus conference was convened on guidelines for the use of CBCT in endodontics, periodontology, reconstructive dentistry and pediatric dentistry. The guidelines are intended for all dentists in order to facilitate the decision as to when the use of CBCT is justified. As a rule, the use of CBCT is considered restrictive, since radiation protection reasons do not allow its routine use. CBCT should therefore be reserved for complex cases where its application can be expected to provide further information that is relevant to the choice of therapy. In periodontology, sufficient information is usually available from clinical examination and periapical radiographs; in endodontics alternative methods can often be used instead of CBCT; and for implant patients undergoing reconstructive dentistry, CT is of interest for the workflow from implant planning to the superstructure. For pediatric dentistry no application of CBCT is seen for caries diagnosis.

SADMFR guidelines for the use of Cone-Beam Computed Tomography/ Digital Volume Tomography.

Cone-Beam Computed Tomography (CBCT) has been introduced in 1998. This radiological imaging procedure has been provided for dentistry and is comparable to computed tomography (CT) in medicine. It is expected that CBCT will have the same success in dental diagnostic imaging as computed tomography had in medicine. Just as CT is responsible for a significant rise in radiation dose to the population from medical X-ray diagnostics, CBCT studies will be accompanied by a significant increase of the dose to our patients by dentistry. Because of the growing concern for an uncritical and consequently rapidly increasing use of CBCT the Swiss Society of Dentomaxillofacial Radiology convened a first consensus conference in 2011 to formulate indications for CBCT, which can be used as guidelines. In this meeting, oral and maxillofacial surgery, orthodontics and temporomandibular joint disorders and diseases were treated and the most important and most experienced users of DVT in these areas were asked to participate. In general, a highly restrictive use of CBCT is required. Justifying main criterion for CBCT application is that additional, therapy-relevant information is expected that should lead to a significant benefit in patient care. All users of CBCT should have completed a structured, high-level training, just like that offered by the Swiss Society of Dentomaxillofacial Radiology.

Is the Schneiderian membrane thickness affected by periodontal disease? A cone beam computed tomography-based extended case series.

OBJECTIVE: The aim was to assess the thickness of Schneiderian membranes (SM) in patients with advanced periodontal disease. METHODS: 17 dentate patients (DG) scheduled for periodontal surgery on maxillary molars were consecutively recruited and cone beam computed tomographies performed for preoperative diagnosis. Twenty-one patients (EG) requiring cone beam computed tomography-based planning of implant placement in the edentulous posterior maxilla served as controls. RESULTS: Schneiderian membrane thickness measured from cone beam computed tomography was significantly greater in the dentate group compared to the edentulous group, both in the first (p = 0.028) and second (p < 0.001) molar position. In the dentate group, clinical signs of periodontal destruction (increased probing pocket depth or furcation involvement) were not associated with Schneiderian membrane thickness. Additional findings, such as periapical lesions (p = 0.008), and the distance between root tips and maxillary sinus revealed a significant association (p = 0.036) with Schneiderian membrane thickness. CONCLUSION: In molar regions with periodontal destruction, Schneiderian membrane thickening occurred, particularly in combination with small bone layers above the root tips or periapical lesions.