A paralleling technique modification to determine the bone crest level around dental implants

Influence of the Tube Angle on the Measurement Accuracy of Peri-Implant Bone Defects in Rectangular Intraoral X-ray Imaging

BACKGROUND

Intraoral radiography in the right-angle technique is the standard procedure to examine the peri-implant bone level in implant follow-up and implant-related studies. For the implementation of the right-angle or parallel technique, mostly ready-made image receptor holders are used. The aim of this experimental study is to analyze changes in the measurement of standardized peri-implant defects caused by a deviation in the position of the image receptor.

METHODS

Eleven Xive® implants (Dentsply Sirona, Bensheim, Germany) were placed in bovine bone, and peri-implant defects of varying depths were created. The preparations were fixed in a specially made test stand, and intraoral radiographs were taken using the right-angle technique with standard film holders at various horizontal and vertical projection angles. Defect measurement was carried out with the imaging software Sidexis 4 V 4.3 (Dentsply Sirona, Bensheim, Germany).

RESULTS

With increasing angular deviation, larger deviations between the measured and the real extent of the defect occurred. Vertical tilting caused significant distortion, while horizontal rotation showed less effect.

CONCLUSION

Intraoral radiography only provides a valid representation of the peri-implant bone level for follow-up or as a tool in implant-related studies if a reproducible projection direction is assured.

Neuroimaging and artificial intelligence for assessment of chronic painful temporomandibular disorders-a comprehensive review

Chronic Painful Temporomandibular Disorders (TMD) are challenging to diagnose and manage due to their complexity and lack of understanding of brain mechanism. In the past few decades' neural mechanisms of pain regulation and perception have been clarified by neuroimaging research. Advances in the neuroimaging have bridged the gap between brain activity and the subjective experience of pain. Neuroimaging has also made strides toward separating the neural mechanisms underlying the chronic painful TMD. Recently, Artificial Intelligence (AI) is transforming various sectors by automating tasks that previously required humans' intelligence to complete. AI has started to contribute to the recognition, assessment, and understanding of painful TMD. The application of AI and neuroimaging in understanding the pathophysiology and diagnosis of chronic painful TMD are still in its early stages. The objective of the present review is to identify the contemporary neuroimaging approaches such as structural, functional, and molecular techniques that have been used to investigate the brain of chronic painful TMD individuals. Furthermore, this review guides practitioners on relevant aspects of AI and how AI and neuroimaging methods can revolutionize our understanding on the mechanisms of painful TMD and aid in both diagnosis and management to enhance patient outcomes.

Standardization of three-dimensional pose of cylindrical implants from intraoral radiographs: a preliminary study

Background

To introduce a theoretical solution to a posteriori describe the pose of a cylindrical dental fixture as appearing on radiographs; to experimentally validate the method described.

Methods

The pose of a conventional dental implant was described by a triplet of angles (phi-pitch, theta-roll, and psi-yaw) which was calculated throughout vector analysis. Radiographic- and simulated-image obtained with an algorithm were compared to test effectiveness, reproducibility, and accuracy of the method. The length of the dental implant as appearing on the simulated image was calculated by the trigonometric function and then compared with real length as it appeared on a two-dimensional radiograph.

Results

Twenty radiographs were analyzed for the present in silico and retrospective study. Among 40 fittings, 37 resulted as resolved with residuals ≤ 1 mm. Similar results were obtained for radiographic and simulated implants with absolute errors of − 1.1° ± 3.9° for phi; − 0.9° ± 4.1° for theta; 0° ± 1.1° for psi. The real and simulated length of the implants appeared to be heavily correlated. Linear dependence was verified by the results of the robust linear regression: 0.9757 (slope), + 0.1344 mm (intercept), and an adjusted coefficient of determination of 0.9054.

Conclusions

The method allowed clinicians to calculate, a posteriori, a single real triplet of angles (phi, theta, psi) by analyzing a two-dimensional radiograph and to identify cases where standardization of repeated intraoral radiographies was not achieved. The a posteriori standardization of two-dimensional radiographs could allowed the clinicians to minimize the patient’s exposure to ionizing radiations for the measurement of marginal bone levels around dental implants.

Peri-implant marginal bone changes with implant-supported metal-ceramic or monolithic zirconia single crowns: A retrospective clinical study of 1 to 5 years

STATEMENT OF PROBLEM

Monolithic zirconia has excellent mechanical and biologic properties. However, evidence of the clinical properties of implant-supported monolithic zirconia prostheses is limited.

PURPOSE

The purpose of this retrospective clinical study was to compare the peri-implant marginal bone changes of metal-ceramic and monolithic zirconia single crowns in the posterior region after prosthetic loading.

MATERIAL AND METHODS

A total of 224 participants treated with 327 implants restored with either metal-ceramic or monolithic zirconia single crowns in the posterior region between 2012 and 2016 were included in this study. Clinical outcomes, including the plaque index, peri-implant probing depth, and bleeding on probing, were recorded, and the marginal bone level was recorded by using the panoramic radiographs obtained at implant placement, second-stage surgery, and the most recent follow-up visit. The included parameters were analyzed with the nonparametric Mann-Whitney tests (α=.05).

RESULTS

The mean follow-up time was 30.4 months, and the cumulative survival rate of implants was 100% and that of the prostheses was 99.1%. The plaque index was 0.46 in the metal-ceramic group, which was significantly higher (P<.05) than 0.37 in the monolithic zirconia group. However, no significant differences (P>.05) were observed in peri-implant probing depth and bleeding on probing between the 2 groups. The marginal bone level at implant placement, second-stage surgery, and the most recent follow-up visit was above the implant platform in both the metal-ceramic and monolithic zirconia groups. The marginal bone changes of the metal-ceramic group was 0.31 mm in the healing period and 0.38 mm in the prosthetic loading period, while in the monolithic zirconia group, it was 0.25 mm in the healing period and 0.43 mm in the prosthetic loading period; no significant differences (P>.05) were observed between the 2 groups.

CONCLUSIONS

The peri-implant marginal bone level change was comparable after prosthetic loading for metal-ceramic and monolithic zirconia single crowns, although monolithic zirconia was associated with reduced plaque.

Influence of glycemic control on survival of zygomatic implants in relation with type-2 diabetes mellitus: 10 years' follow-up results

It is hypothesized that under optimal glycemic control (GC), there is no difference in the survival of implants placed in the zygomatic bone of edentulous patient with and without type-2 diabetes mellitus (T2DM). Purpose: The aim was to assess the influence of GC on survival of implants placed in the zygomatic bone of edentulous patient with and without T2DM at 10-years' follow-up. Twenty patients with T2DM (10 with poorly- and 10 with well-controlled T2DM) and 12 patients without T2DM were included. Hemoglobin A1c (HbA1c) levels were recorded and demographic data was collected from all participants. Peri-implant inflammatory parameters (plaque index [PI], probing depth [PD], crestal bone loss [BL] and gingival index [GI]) were measured in all patients. Group comparisons were done and P-values, which were less than 0.01 were indicative of statistical significance. Twenty and 12 male patients with and without T2DM, respectively were included. Among patients with T2DM, 10 and 10 individuals had poorly- and well-controlled T2DM, respectively.  The mean HbA1c levels were significantly higher in patients with poorly- (9.2 ± 0.7%) compared with well-controlled T2DM (4.8 ± 0.3%) (P<0.01) and non-diabetic individuals (4.6 ± 0.3%) (P<0.01). The crestal BL on the mesial (P<0.01) and distal (P<0.01) surfaces, PD (P<0.01), PI (P<0.01), and GI (P<0.01) were significantly higher around all zygoma implants placed in patients with poorly-controlled T2DM compared with patients with well-controlled T2DM and patients without T2DM. These clinicoradiographic parameters were comparable around zygoma implants placed in patient with well-controlled T2DM and in subjects without T2DM.  Optimal glycemic control is essential for the long-term stability of zygomatic plants in patients with T2DM.

Influence of moderate cigarette-smoking on the peri-implant clinicoradiographic inflammatory parameters around cement- and screw-retained dental implants

The aim was to assess the influence of moderate cigarette-smoking on the clinical (bleeding on probing [BoP] and probing depth [PD]) and radiographic (crestal bone resorption [CBR]) around cement- and screw-retained dental implants at 5 years' follow-up. A questionnaire was used to collect information about age, gender, smoking history, duration of implants in function, jaw location of the implant, and daily toothbrushing and flossing. Peri-implant BoP, PD and CBR were measured in all groups. Group comparisons were performed using one-way analysis of variance and for multiple comparisons, the Bonferroni Post hoc adjustment test was performed. Level of significance was set at P<0.05. Forty-eight patients (25 smokers and 23 non-smokers) had cement-retained dental implants; and 48 (24 smokers and 24 non-smokers) had screw-retained dental implants. Among patients with cement and screw-retained dental implants, PD (P<0.05) and CBR (P<0.05) were significantly higher among smokers than non-smokers. The peri-implant sites that demonstrated BoP were statistically significantly higher among non-smokers (P<0.05) than smokers among patients with cement- and screw-retained dental implants. There was no statistically significant difference in peri-implant PD and CBR among smokers with cement- and screw-retained dental implants. Among non-smokers with cement and screw-retained dental implants, there was no statistically significant difference in BoP, PD and CBR. Cigarette-smoking is associated with an increased PD and CBR around cement- and screw-retained dental implants. Cigarette-smoking increases peri-implant soft tissue inflammation as well as loss of crestal bone and this relationship is independent of the type of implant retention protocol used.The author recommends that cement- and screw-retained dental implants are suitable for prosthesis restoration in non-smokers. Further studies on dual-smokers (individuals smoking cigarettes and other forms of tobacco products) are needed related to the clinicoradiographic inflammatory parameters around cement- and screw-retained dental implants.

Using acrylic customized X-ray positioning stents for long-term follow-up studies

Objectives

Long-term assessment of teeth, dental implants, and their corresponding structures is vital to obtain more data concerning the achievement or disappointment of different treatment modalities in clinical situations.

Aim

This report aimed to verify the usage of customized X-ray positioning stents suitable for long-term follow-up studies.

Material and methods

Two acrylic stents were compared. An X-ray positioning device was built by the incorporation of a bite piece within an acrylic hard nightguard stent and a conventional acrylic film holder were fabricated for 20 patients. Four radiographs were taken of each patient (two of each film holder) at the initial time and after 3 months. Specific linear measurements of the premolar diameter (CEJ width) and the height between the CEJ and the apex were made of all of the radiographs to determine the reproducibility and accuracy of the procedure.

Results

The customized X-ray positioning positing stent showed a slight increase in the mean difference of the measurements of the value of the real ratio, demonstrating that the measurements were precise and reliable images of the premolars. The acrylic film holder showed a significant difference in the measurements of the value of the real ratio, indicating unreliable images of the premolars.

Conclusion

The device provided reliable linear measurements and produced reproducible images suitable for studies depending on the follow-up analysis.

A 22-Year Follow Up of Immediate Implant Placement without Bone Augmentation: A Case Series Study

PURPOSE

To retrospectively evaluate the treatment outcome of immediate implants placed in fresh extraction sockets without bone augmentation after 22 years of function.

MATERIALS AND METHODS

The study group received implant therapy in 1997, including surgical placement and prosthodontic rehabilitation. The mean age of the subjects at the time of implant placement was 40 ± 5.54 years. A total of 35 subjects received 36 implants in fresh extraction sockets without bone augmentation. Definitive prostheses were placed 4 to 6 months after implant placement. Implant treatment outcomes were evaluated using clinical and radiographic parameters obtained during follow-up visits at 1, 5, 10, 15, 20, and 22 years after prosthetic loading.

RESULTS

Among the 35 treated subjects, five patients moved out of the country and could not be evaluated at the follow-up times. A total of 29 subjects were included in the study with a drop-out rate of 14.1%. Of these, one patient lost the implant during the osseointegration period before prosthodontic treatment. No other implant failure or complication during the rest of the follow-up period was reported, thus giving a cumulative survival rate of 97.2% during the 22-year follow-up. The change in marginal bone level was less than 2 mm in most subjects at the 22-year examination. The mean bone loss from baseline to 22-year follow-up was 1.61 mm, and the mean bone level at the 22-year follow-up examination was situated at 2.13 ± 0.023 mm from the implant platform, which was used as the reference point.

CONCLUSIONS

Immediate implant placement in extraction sockets exhibits excellent prognosis even when bone augmentation is not performed.

A methodological approach to standardize and control the quality of the position and alignment of lamina implants on two-dimensional radiographs

OBJECTIVES

We sought to validate a new method to detect the degree of correlation between simulated and real tilted blade implants as they appear on a single two-dimensional radiograph.

METHODS

The angular correction factor (CF^) was defined as the coupling of two subsequent angle transformations, a set of five angular values describing the theoretical radiographic appearance of the blade implant: (1) three consecutive rotations about the axes of the blade ([Formula: see text], θ, and ψ, standing for pitch, roll, and yaw, respectively) to represent the polarization directions; (2) a two-dimensional projection defined by two angles (λ and [Formula: see text], respectively, longitude and latitude) to represent the vector of the X-ray beam intersecting the detector plate. Data of patients who received fixed prostheses supported by blade-form implants were employed to calculate a dimensional correction factor (CF°), a specific length through the major axis. The simulation of a distorted radiograph of a blade positioned in space was compared with the real radiograph. Differences in the angular measurements served as an initial test to assess the effectiveness of the method.

RESULTS

In the acquired sets of periapical radiographs, mean misalignments of + 3.58° in longitude and - 0.04° in latitude were registered. The following variations were detected during the accuracy testing: the absolute error was 0.1 ± 7.5° for angle [Formula: see text]; 2.4 ± 6.7° for angle θ; - 1.0 ± 3.7° for angle ψ; 4.5 ± 8.6° for angle λ; and 2.0 ± 9.3° for angle [Formula: see text]. The linear dependence between CF° and CF^ was estimated by a robust linear regression: slope + 0.991, intercept + 0.007, and adjusted R² 0.992.

CONCLUSIONS

This a posteriori analysis introduces the explicit trigonometric equations of the theoretical standard (CF^) used to describe the blade implant radiographic position and misalignment on two-dimensional radiographs.

Pose determination of a blade implant in three dimensions from a single two-dimensional radiograph

The aim of the study was to introduce a mathematical method to estimate the correct pose of a blade by evaluating the radiographic features obtained from a single two-dimensional image. Blade-form implant bed preparation was performed using the piezosurgery device, and placement was attained with the use of magnetic mallet. The pose determination of the blade was described by means of three consecutive rotations defined by three angles of orientation (triplet φ, θ and ψ). Retrospective analysis on periapical radiographs was performed. This method was used to compare implant (axial length along the marker, i.e. the implant structure) vs angular correction factor (a trigonometric function of the triplet). The accuracy of the method was tested by generating two-dimensional radiographic simulations of the blades, which were then compared with the images of the implants as appearing on the real radiographs. Two patients had to be excluded from further evaluation because the values of the estimated pose angles showed a too-wide range to be effective for a good standardization of serial radiographs: intrapatient range from baseline to 1-year survey was > of a threshold determined by the clinicians (30°). The linear dependence between implant (CF°) and angular correction factor (CF^) was estimated by a robust linear regression, yielding the following coefficients: slope, 0.908; intercept, -0.092; and coefficient of determination, 0.924. The absolute error in accuracy was -0.29 ± 4.35, 0.23 ± 3.81 and 0.64 ± 1.18°, respectively, for the angles φ, θ and ψ. The present theoretical and experimental study established the possibility of determining, a posteriori, a unique triplet of angles (φ, θ and ψ) which described the pose of a blade upon a single two-dimensional radiograph, and of suggesting a method to detect cases in which the standardized geometric projection failed. The angular correction of the bone level yielded results very close to those obtained with an internal marker related to the implant length.

Accuracy of enhancement filters in measuring in vitro peri-implant bone level

OBJECTIVES

To identify the accuracy of enhancement filters of an intraoral phosphor-plate system for measuring the simulated peri-implant bone level.

MATERIALS AND METHODS

A total of 20 titanium implants (Titamax(®) ) were placed into six fragments of bovine ribs and defects simulating bone loss were created. Periapical radiographs were taken with a phosphor-plate system (Vista Scan(®) ) according to the paralleling standard technique, and nine enhancement filters were applied: fine, caries 1, caries 2, perio, endo, noise reduction, invert, emboss, and sculpture. The Friedman test compared the radiographic measurements of the defects to those obtained on the bovine ribs with a digital caliper. Intra- and interobserver agreement was calculated with the intra-class correlation coefficient (ICC).

RESULTS

The ICC values showed excellent intra- and interobserver agreement. The caries1, caries2, endo, and perio filters resulted on measurements statistically different from both the original images and the measurements of the digital caliper (P < 0.05). The other filters did not show statistically significant differences from the original images nor from the measurements of the digital caliper.

CONCLUSION

In addition to the original images, the fine and emboss filters resulted on the most precise measures. The caries1, caries2, endo, and perio filters were the less accurate for measuring the peri-implant bone level.