Reliability of assessing interproximal bone loss by digital radiography: intrabony defects

Use of Collagen Membrane in the Treatment of Periodontal Defects Distal to Mandibular Second Molars Following Surgical Removal of Impacted Mandibular Third Molars: A Comparative Clinical Study

The study aims to assess the efficacy of using collagen membrane in the treatment of distal periodontal defects of mandibular second molars following the removal of mesioangularly or horizontally impacted mandibular third molars surgically. Forty sites in twenty patients with bilaterally impacted mandibular third molars (mesioangular or horizontal) were considered for the study. In 20 test sites (Group A), after surgical removal of the mandibular third molar, a resorbable collagen membrane barrier was placed on the distal aspect of the mandibular second molar to cover the post-surgical bone defect. In the other control 20 sites (Group B), the same surgical procedure was repeated without placing any membrane barrier. The clinical parameters recorded were Oral Hygiene Index Simplified (OHI-S), Probing pocket depth (PPD), Clinical attachment level (CAL), and radiographic assessment of alveolar bone level (ABL). OHI-S score of most of the patients was observed to be satisfactory. Group A was observed to achieve a statistically significant reduction in PPD, CAL, and ABL gain compared to Group B. The improvements indicated that the use of collagen membrane facilitates early wound stabilization and promotes primary closure of the defect. This recovery is achieved through its unique property to assist fibrinogenesis over osteoconduction. Further longitudinal studies are needed to confirm the present findings.

Periodontal infrabony defects: Systematic review of healing by defect morphology following regenerative surgery

BACKGROUND

It is thought that infrabony defect morphology affects the outcome of periodontal regenerative surgery. However, this has not been systematically investigated.

AIMS

To investigate how well defect morphology is described in papers reporting regenerative therapy of periodontal infrabony defects and to investigate its effect on clinical and radiographic outcomes.

MATERIALS AND METHODS

A search was conducted in 3 electronic databases for publications reporting clinical and radiographic outcomes of periodontal intra-bony defects after regenerative therapy, divided by defect morphology.

RESULTS

The initial search resulted in 4487 papers, reduced to 143 after first and second screening. Fifteen of these publications were suitable for a fixed-effects meta-analysis. Initial defect depth was found to influence radiographic bone gain 12 months post-surgery, while narrower angles and increased number of walls influenced both radiographic bone gain and clinical attachment level (CAL) gain at 12 months. These associations seemed to occur irrespective of biomaterials used. Risk of bias ranged from low to high.

CONCLUSION

Deeper defects with narrower angles and increased number of walls exhibit improved CAL and radiographic bone gain at 12 months post-regenerative surgery. More data are needed about other aspects of defect morphology such as extension to buccal/lingual surfaces.

Accuracy of extraoral bite-wing radiography in detecting proximal caries and crestal bone loss

BACKGROUND

Extraoral bite-wing (EB) radiography is an imaging technology used in dentistry. The authors conducted an in vivo study comparing the accuracy of intraoral bitewing (IB) radiographs and EB radiographs for proximal caries and bone loss diagnosis.

METHODS

The authors recruited 116 patients who received IB radiographs to receive EB radiographs. The 5 calibrated authors made a consensus radiographic diagnosis of proximal caries and crestal bone loss. For this study, they assumed IB radiographs as the criterion standard. Next, they obtained EB radiographs for the 116 patients and calculated sensitivity, specificity, and false-positive rates against each patient's IB radiograph.

RESULTS

The patients' EB radiographs revealed a significantly greater number of caries and crestal bone loss findings compared with their IB radiographs. The EB radiographs had a high to excellent sensitivity and moderate to low specificity of caries and crestal bone loss findings, respectively. Considering IB radiographs to be the criterion standard, the false-positive rate for EB radiographs was moderate for caries and high for bone loss diagnosis.

CONCLUSIONS

The EB radiographs, which generate fewer images of overlapping proximal surfaces, have the advantage of detecting more carious lesions and bone loss findings than the IB radiographs do, but with the disadvantage of more false-positive diagnoses. Further research is needed to evaluate if the false-positive findings represent true carious lesions and bone loss.

PRACTICAL IMPLICATIONS

EB radiography is a promising technology, which has several advantages over traditional IB radiography. Clinicians should be aware of false-positive diagnosis of caries and bone loss with EB radiography.

Assessment of periodontal bone level revisited: a controlled study on the diagnostic accuracy of clinical evaluation methods and intra-oral radiography

OBJECTIVES

The accuracy of analogue and especially digital intra-oral radiography in assessing interdental bone level needs further documentation. The aim of this study was to compare clinical and radiographic bone level assessment to intra-surgical bone level registration (1) and to identify the clinical variables rendering interdental bone level assessment inaccurate (2).

MATERIALS AND METHODS

The study sample included 49 interdental sites in 17 periodontitis patients. Evaluation methods included vertical relative probing attachment level (RAL-V), analogue and digital intra-oral radiography and bone sounding without and with flap elevation. The latter was considered the true bone level. Five examiners evaluated all radiographs.

RESULTS

Significant underestimation of the true bone level was observed for all evaluation methods pointing to 2.7 mm on average for analogue radiography, 2.5 mm for digital radiography, 1.8 mm for RAL-V and 0.6 mm for bone sounding without flap elevation (p < 0.001). Radiographic underestimation of the true bone level was higher in the (pre)molar region (p ≤ 0.047) and increased with defect depth (p < 0.001). Variation between clinicians was huge (range analogue radiography 2.2-3.2 mm; range digital radiography 2.1-3.0 mm).

CONCLUSION

All evaluation methods significantly underestimated the true bone level. Bone sounding was most accurate, whereas intra-oral radiographs were least accurate. Deep periodontal defects in the (pre)molar region were most underrated by intra-oral radiography.

CLINICAL RELEVANCE

Bone sounding had the highest accuracy in assessing interdental bone level.

Is cement penetration in TKR reduced by not using a tourniquet during cementation? A single blinded, randomized trial

Despite suggestions that tourniquet inflation during total knee replacement reduces bleeding and hence improves cement penetration, no studies exist supporting this widely held belief. In this single-blinded, single-surgeon, randomized controlled trial, the tourniquet inflation during cementation group ( n = 20) did not have greater tibial cement penetration compared to a no tourniquet group ( n = 20). No statistically significant differences in semiautomatic digitally measured average and central radiographic tibial plateau penetration values were observed between the two groups ( p = 0.93; p = 0.84). Tourniquet inflation during cementation does not appear to improve tibial cementation penetration.

Comparison of bone mineral density among pre- and post-menopausal women with and without chronic generalized periodontitis

Background

There have been a very limited number of studies regarding the assessment of bone mineral density (BMD) using dual energy X-ray absorptiometry scan. Hence, the purpose of the study was to assess the relationship between BMD and periodontal health in three different study groups.

Materials and Methods

The study comprised of thirty female individuals who were categorized into three groups: ten premenopausal women with healthy periodontium (Group A), ten premenopausal women with generalized chronic periodontitis (Group B), and ten postmenopausal women with generalized chronic periodontitis (Group C). Number of teeth, plaque index, probing depth, clinical attachment level, interproximal alveolar bone loss, T-score for dual femur and posteroanterior (PA) spine, and BMD for dual femur and PA spine of each individual were recorded in all the three groups.

Results

The BMD and T-score of dual femur and PA spine were found to be low in Group C when compared to Group A and B which was statistically significant.

Conclusion

Postmenopausal women with generalized chronic periodontitis (Group C) exhibited severe periodontal destruction with less BMD. Hence, it is suggested that periodontitis may be a risk indicator for osteoporosis in postmenopausal women and vice versa.

Retrospective success and survival rates of dental implants placed after a ridge preservation procedure

AIM

Ridge preservation is any procedure that takes place at the time of, or shortly after an extraction, to minimise resorption of the ridge and maximise bone formation within the socket. The aim of this project is to investigate the outcome of implant treatment following ridge preservation and compare it to an ungrafted implant control group.

METHODS AND MATERIALS

Following ethics approval, an electronic and manual search of patient records was conducted, and appropriate cases of implant placement following a ridge preservation procedure were identified. Forty-two patients with 51 implants at ridge-preserved sites were examined by one author (PA) with the following parameters assessed at each implant: pocket probing depth, bleeding on probing, presence/absence of plaque and radiographic bone loss. Clinical and radiographic findings were compared to an ungrafted implant control group and analysed by years in function.

RESULTS

There was a 100% survival rate of implants in ridge-preserved sites. In the majority of cases, ridge preservation was performed in the anterior maxilla with a flap raised and the use of deproteinised bovine bone mineral and collagen membrane materials. The mean time in function was 31 (±24) months with a range of 2-102 months. Differences in the mean PPD, BOP, plaque index and radiographic bone loss were not statistically significant between implants at ridge-preserved or ungrafted sites. The overall success rate was around 58% for ungrafted implants and around 51% for implants in ridge-preserved sites. However, this difference was not statistically significant.

CONCLUSION

In this retrospective study, implant placement at ridge-preserved sites was a predictable procedure that led to very high survival rates and similar success rates to implant placement at ungrafted sites.

Comparison of diagnostic accuracy of conventional intraoral periapical and direct digital radiographs in detecting interdental bone loss

BACKGROUND

Periodontitis is an inflammatory disease of the supporting tissues of the teeth caused by specific microorganisms, resulting in destruction of the periodontal ligament and alveolar bone. Progressive loss of alveolar bone is the salient feature of periodontal disease. Accurate detection of periodontal disease with the use of radiographs helps in diagnosis, treatment and prognosis.

AIMS

The present study aims to compare the efficacy of conventional intraoral periapical (IOPA) and direct digital radiographs (RVG) in detecting interdental alveolar bone loss using intrasurgical (IS) measurements as the gold standard.

MATERIALS AND METHODS

Thirty patients elected to undergo periodontal flap surgery with periodontitis computing to 60 interdental alveolar defects on mandibular first molars were considered. IOPA and RVG were captured using standardized techniques. Bone loss measurements in IOPA and RVG were compared to the IS measurements.

STATISTICAL ANALYSIS

Statistical analysis was carried out using student t test and ANOVA with the help of SPSS software and p-value <0.05 was considered as significant.

RESULTS

Both IOPA and RVG underestimated the bone loss measurements when compared to IS measurements which was statistically significant (p<0.0001). Bone loss measurements in RVG were closer to IS measurements than IOPA.

CONCLUSION

Both the radiographic techniques IOPA and RVG underestimated bone loss by 1.5-2.5 mm. RVG was superior to IOPA for the detection of interdental bone loss due to reduced time and radiation exposure to obtain the same diagnostic information.

Evaluation of diagnostic accuracy of conventional and digital periapical radiography, panoramic radiography, and cone-beam computed tomography in the assessment of alveolar bone loss

Background:

To evaluate the diagnostic accuracy of different radiographic methods in the assessment of proximal alveolar bone loss (ABL).

Materials and Methods:

ABL, the distance between cement-enamel junction and alveolar bone crest, was measured in 70 mandibular human teeth – directly on the mandibles (control), using conventional periapical radiography with film holders (Rinn XCP and Han-Shin), digital periapical radiography with complementary metal-oxide semiconductor sensor, conventional panoramic, and cone-beam computed tomography (CBCT). Three programs were used to measure ABL on the images: Image tool 3.0 (University of Texas Health Sciences Center, San Antonio, Texas, USA), Kodak Imaging 6.1 (Kodak Dental Imaging 6.1, Carestream Health^®, Rochester, NY, USA), and i-CAT vision 1.6.20. Statistical analysis used ANOVA and Tukey's test at 5% significance level.

Results:

The tomographic images showed the highest means, whereas the lowest were found for periapical with Han-Shin. Controls differed from periapical with Han-Shin (P < 0.0001). CBCT differed from panoramic (P = 0.0130), periapical with Rinn XCP (P = 0.0066), periapical with Han-Shin (P < 0.0001), and digital periapical (P = 0.0027). Conventional periapicals with film holders differed from each other (P = 0.0007). Digital periapical differed from conventional periapical with Han-Shin (P = 0.0004).

Conclusions:

Conventional periapical with Han-Shin film holder was the only method that differed from the controls. CBCT had the closest means to the controls.

Comparative evaluation of periosteum as a barrier membrane with and without an alloplastic bone graft in periodontal osseous defects: A 9 months follow-up study

BACKGROUND

Regenerative procedures frequently include the use of barrier membranes and bone grafting materials to encourage the growth of key surrounding tissues. The present study aims to evaluate and compare the ability of periosteum in intrabony defect regeneration.

MATERIALS AND METHODS

A total of ten intrabony defects were equally divided in two treatment groups. Group I consisted of Periosteum used as a barrier memebrane and Group II of periosteum as barrier membrane alongwith graft material. Nine months post operative evaluation of defect fill was done radiographically.

RESULTS

Mean defect fill (CEJ-BBD) was found to be significantly lower in Group II as compared to Group I (P = 0.041).

CONCLUSION

Within the limitations of this study, alloplastic graft material supplimentation results in better regeneration with Periosteum used as a barrier membrane.

Image enhancement of digital periapical radiographs according to diagnostic tasks

Purpose

This study was performed to investigate the effect of image enhancement of periapical radiographs according to the diagnostic task.

Materials and Methods

Eighty digital intraoral radiographs were obtained from patients and classified into four groups according to the diagnostic tasks of dental caries, periodontal diseases, periapical lesions, and endodontic files. All images were enhanced differently by using five processing techniques. Three radiologists blindly compared the subjective image quality of the original images and the processed images using a 5-point scale.

Results

There were significant differences between the image quality of the processed images and that of the original images (P<0.01) in all the diagnostic task groups. Processing techniques showed significantly different efficacy according to the diagnostic task (P<0.01).

Conclusion

Image enhancement affects the image quality differently depending on the diagnostic task. And the use of optimal parameters is important for each diagnostic task.

Comparative study between two techniques for alveolar bone loss assessment: A pilot study

OBJECTIVE

To conduct a comparative study between two techniques for assessment of alveolar bone loss.

MATERIALS AND METHODS

Absolute and relative techniques were evaluated. The sample consisted of 16 radiographs supposed to meet a single criterion: The reference points applied (Cementum-enamel junction (CEJ) alveolar bone crest and root apex) should be visible. Bone height was measured in the selected radiographs as the percentage of root length through both techniques. Data were submitted to the Statistical Package for Social Science software. Results obtained by both methods were converted into bone loss index values and then categorized. Sensitivity and specificity of the relative technique, compared to the absolute technique, were calculated. Wilcoxon test and the Bland and Altman's method were employed for comparisons. Significance level was set at 5%.

RESULTS

For the absolute and relative techniques, means of bone loss index were respectively of 4.81 (±2.25) and 4.75 (±1.80). Bone loss index ≥6 (alveolar bone loss ≥50%) was found in 5 (31.2%) teeth, in the absolute technique, and in 4 (25%) teeth, according to the relative technique. There was no statistically significant difference between both methods (P>0.05). According to the Bland and Altman's method, it was verified a bias of 0.06, and limits of upper and lower agreement of, respectively, 1.58 and -1.45. Sensitivity of 0.8 and specificity of 1 were found for the relative technique compared to the absolute one.

CONCLUSION

There was no significant difference between the techniques evaluated, and the relative technique was found to be reliable for measuring alveolar bone loss.

Measurements of simulated periodontal bone defects in inverted digital image and film-based radiograph: an in vitro study

Purpose

This study was performed to compare the inverted digital images and film-based images of dry pig mandibles to measure the periodontal bone defect depth.

Materials and Methods

Forty 2-wall bone defects were made in the proximal region of the premolar in the dry pig mandibles. The digital and conventional radiographs were taken using a Schick sensor and Kodak F-speed intraoral film. Image manipulation (inversion) was performed using Adobe Photoshop 7.0 software. Four trained examiners made all of the radiographic measurements in millimeters a total of three times from the cementoenamel junction to the most apical extension of the bone loss with both types of images: inverted digital and film. The measurements were also made in dry mandibles using a periodontal probe and digital caliper. The Student's t-test was used to compare the depth measurements obtained from the two types of images and direct visual measurement in the dry mandibles. A significance level of 0.05 for a 95% confidence interval was used for each comparison.

Results

There was a significant difference between depth measurements in the inverted digital images and direct visual measurements (p>|t|=0.0039), with means of 6.29 mm (IC_95%:6.04-6.54) and 6.79 mm (IC_95%:6.45-7.11), respectively. There was a non-significant difference between the film-based radiographs and direct visual measurements (p>|t|=0.4950), with means of 6.64mm(IC_95%:6.40-6.89) and 6.79mm(IC_95%:6.45-7.11), respectively.

Conclusion

The periodontal bone defect measurements in the inverted digital images were inferior to film-based radiographs, underestimating the amount of bone loss.

Determination of vertical interproximal bone loss topography: correlation between indirect digital radiographic measurement and clinical measurement

Background

Diagnosis and accuracy in determining the exact location, extent and configuration of bony defects of the jaw are of utmost importance to determine prognosis, treatment planning and long-term preservation of teeth. If relatively accurate diagnosis can be established by radiography, proper treatment planning prior to treatment procedures will be possible.

Objectives

The aim of the present study was to assess the correlation between indirect digital radiographic measurements and clinical measurements in determining the topography of interproximal bony defects.

Patients and Methods

Twenty interproximal bony defects, preferably in the mandibular and maxillary 5↔5 area were selected and radiographed using the parallel periapical technique. The radiographs were corrected and digitized on a computer using “Linear Measurement” software; then the three parameters of the base of defect (BD), alveolar crest (AC) and cementoenamel junction (CEJ) were determined using a software. Subsequent to radiographic measurements, clinical measurements were carried out meticulously during flap procedures. Then linear measurements were carried out using a periodontal probe to determine the defect depth and its mesiodistal width. Then the amount of correlation between these two measurements was assessed by Pearson's correlation coefficient.

Results

The correlation between clinical and radiographic measurements in defect depth determination, in the evaluation of defect angle and in determination of defect width were 88%, 98% and 90%, respectively.

Conclusions

Indirect digital radiographic technique can be used to diagnose intra-osseous defects, providing a better opportunity to treat bony defects.

Radiographic and clinical outcomes of implants placed in ridge preserved sites: a 12-month post-loading follow-up

OBJECTIVE

The aim of this clinical study was to evaluate the interproximal radiographic bone levels and the survival/success rate of dental implants placed in alveolar ridges previously preserved with a synthetic bone substitute or a bovine xenograft.

MATERIAL AND METHODS

Alveolar ridge preservation was performed in 27 patients who were randomly assigned in two groups. In the test group (n = 14), the extraction socket was treated with a synthetic bone graft Straumann Bone Ceramic; SBC and a collagen barrier, whereas in the control group (n = 13) a deproteinized bovine bone mineral (DBBM) and the same collagen barrier were used. After 8 months of healing, titanium dental implants with a hydrophilic surface were placed in the preserved ridges. During surgery, 9/13 implants in the SBC group and 8/12 implants in the DBBM group presented with either dehiscence or fenestration defects and required additional bone augmentation. The implants were loaded at 4 months following placement and were followed up for 1 year post-loading. Interproximal radiographic bone levels were evaluated in standardized periapical radiographs at loading and 1 year post-loading. Probing pocket depth, gingival recession and bleeding upon probing were recorded at implants and neighbouring teeth. The success rate of the implants was evaluated according to criteria set by Albrektsson et al. (1986).

RESULTS

The survival rate of the implants in both groups was 100% at 1-year post-loading. No statistically significant differences in any of the clinical and radiographic measurements were detected between the two groups (P < 0.05). The success rate of the implants was 84.6% (11/13) in the SBC group and 83.3% (10/12) in the DBBM group.

CONCLUSION

Equivalent success and survival rates (as well as similar radiographic changes) of dental implants placed in alveolar ridges previously preserved with SBC or DBBM should be anticipated.

Role of space provision in regeneration of localized two-wall intrabony defects using periosteal pedicle graft as an autogenous guided tissue membrane

BACKGROUND

Marginal pedicle periosteum (MPP) has been used as a rigid membrane in guided tissue regeneration (GTR) for osseous defects. The present study aims to study the effect of space provision by an alloplastic graft material in bone defect area (BDA) reduction of 2-wall defects.

METHODS

Twenty interproximal intrabony 2-wall defects in healthy non-smoking patients with chronic periodontitis were randomly divided in control (group 1, periosteum alone) and experimental (group 2, periosteum with alloplastic graft material) groups. Measurements of probing depth (PD), clinical attachment level (CAL), and radiographic BDA were done at the baseline and 6-month postoperative evaluations.

RESULTS

The 6-month postoperative assessment showed clinical and radiographic improvements with PD reduction, CAL gain, and changes in BDA in both groups, which was statistically significant compared with baseline (P <0.05). However, BDA reduction was statistically greater in group 2 (48.88% ± 18.61%) compared with group 1 (14.08% ± 12.97%) at the 6-month follow-up (P = 0.009).

CONCLUSION

Within the limitations of this study, it can be concluded that space provision by an alloplastic graft material increases the regenerative potential of MPP as a GTR membrane and results in increased defect fill.

Comparison of radiovisiography and digital volume tomography to direct surgical measurements in the detection of infrabony defects

OBJECTIVES

To compare the linear measurements of Radiovisiography (RVG) and Digital volume tomography (DVT) to direct surgical measurements in the detection of periodontal infrabony defects.

STUDY DESIGN

RVG and DVT images were taken prior to periodontal surgery for 28 infrabony periodontal defects. After defect debridement, direct bony defect measurements were made from the cemento enamel junction (CEJ) to the base of the defect (CEJ-BD) and to the alveolar crest (CEJ-AC) with a periodontal probe. These same measurements were made on the RVG and DVT images and then compared to the direct surgical values.

RESULTS

DVT correlated strongly with surgical measurements, whereas RVG correlated less favorably (P=0.0109, P=0.0193 respectively).No significant difference for CEJ-AC (P=0.0599) was seen between DVT and surgical measurements; however, there was a significant difference for the distance CEJ-BD (P=0.0105).

CONCLUSION

DVT technique is significantly more accurate than RVG in the detection of infrabony periodontal defects. Key words:Tomography, volume computed, dental radiovisiography, periodontal diseases.

Retrospective analysis of survival rates and marginal bone loss on short implants in the mandible

OBJECTIVES

Short implants have become an interesting alternative to bone augmentation in dental implantology. Design of shorter implants and longer surveillance times are a current research issue. The goal of this study was to show the survival rates of short implants below 9 mm in the partly edentulous mandibular premolar and molar regions with fixed prosthetics. Marginal vertical and 2D bone loss was evaluated additionally. Different implant designs are orientationally evaluated.

MATERIAL AND METHODS

A total of 247 dental implants with fixed prosthetics (crowns and bridges) in the premolar and molar region of the mandible were evaluated; 47 implants were 9 mm or shorter. Patient data were evaluated to acquire implant survival rates, implant diameter, gender and age. Panoramic X-rays were analysed for marginal bone loss.

RESULTS

Average surveillance time was 1327 days. Cumulative survival rate (CSR) of short implants was 98% (1 implants lost) compared to 94% in the longer implants group without significance. Thirty-five of the short implants were Astratech (0 losses) and 12 were Camlog Screw Line Promote Plus (1 loss). Early vertical and two-dimensional marginal bone loss was not significantly different in short and regular length implant group with an average of 0.6 mm and 0.7 mm(2) in short implants over the observation period.

CONCLUSIONS

Within the limitations of this study, we conclude that short implants with a length of 9 mm or less have equal survival rates compared with longer implants over the observation period of 1-3 years.

Radiographic alveolar bone changes following ridge preservation with two different biomaterials

OBJECTIVES

The aim of this randomized controlled trial was to evaluate radiographical bone changes following alveolar ridge preservation with a synthetic bone substitute or a bovine xenograft.

METHODS

Alveolar ridge preservation was performed in 27 patients randomized in two groups. In the test group (n=14), the extraction socket was treated with Straumann bone ceramic(®) (SBC) and a collagen barrier membrane (Bio-Gide(®)), whereas in the control group (n=13) with deproteinized bovine bone mineral and the same barrier. Standardized periapical X-rays were taken at 4 time points, BL: after tooth extraction, GR: immediately after socket grafting, 4M: 16 weeks, 8M: 32 weeks post-operatively. The levels of the alveolar bone crest at the mesial (Mh), and distal (Dh) and central aspects of the socket were measured at all time points. All the radiographs obtained were subtracted from the follow-up images. The gain, loss and unchanged areas in terms of grey values were tested for significant difference between the two groups.

RESULTS

In the test group, the Mh and Dh showed a mean difference (± standard deviation) of 0.9 ± 1.2 and 0.7 ± 1.8 mm, respectively, among BL-8M. In the control group, the Mh and Dh showed a mean difference of 0.4 ± 1.3 and 0.7 ± 1.3 mm, respectively (P>0.05). Both treatments presented similar gain in grey values between BL-GR, BL-4M and BL-8M. The SBC presented less loss in grey values between BL-4M and BL-8M (P<0.05). Radiographic assessment underestimated the intrasurgical measurements (mesial and distal) of an average 0.3 mm (95% CI, 0.02-0.6).

CONCLUSION

Both types of bone grafts presented similar radiographic alveolar bone changes when used for alveolar ridge preservation.

Influence of individual brightness and contrast adjustment on accuracy of radiographic measurements of infrabony defects

OBJECTIVES

To assess the accuracy of radiographic measurements of infrabony defects and to compare the accuracy with and without individual digital adjustment of brightness and contrast.

METHODS

In 41 periodontitis patients (19 females, 22 males; age range 23-73 years), 50 radiographs of 50 infrabony defects were obtained. All radiographs were digitized. Using a personal computer program, the linear distances between cemento-enamel junction (CEJ) and alveolar crest (AC) and between CEJ and bony defect (BD), and the depth of the infrabony defect (INFRA), were measured twice, according to the individual judgement of the radiographic examiner: (1) without digital adjustment (W) and (2) after use of contrast and brightness adjustment (A). Intrasurgical bone measurements served as the gold standard. The accuracy of measurements with or without digital adjustment was compared.

RESULTS

Radiographic measurements underestimated the gold standard for CEJ-BD (W: 1.1 mm ± 1.8 mm, P < 0.001; A: 1.0 mm ± 1.9 mm, P = 0.001). Both CEJ-AC (W: 0.2 mm ± 2.5 mm; A: 0.5 mm ± 2.6 mm) and INFRA (W: -0.4 mm ± 2.4 mm; A: -0.6 mm ± 2.5 mm) measurements came close to the gold standard. Statistically significant differences between W and A regarding accuracy were not observed.

CONCLUSIONS

The measurement tool used in this study provided high-accuracy measurements of periodontal bone loss in INFRA. Individual brightness and contrast adjustment failed to improve accuracy.

Modern dental imaging: a review of the current technology and clinical applications in dental practice

A review of modern imaging techniques commonly used in dental practice and their clinical applications is presented. The current dental examinations consist of intraoral imaging with digital indirect and direct receptors, while extraoral imaging is divided into traditional tomographic/panoramic imaging and the more recently introduced cone beam computed tomography. Applications, limitations and current trends of these dental "in-office" radiographic techniques are discussed.

Influence of image filters on the reproducibility measurements of alveolar bone loss

The reproducibility of measurements of alveolar bone loss on radiographs may be a problem on epidemiologic studies, as they are based on comparisons of the diagnosis of various examiners. The aim of the present research paper was to assess the inter- and intra-examiner reproducibility of measurements of the interproximal alveolar bone loss on non-manipulated digital radiographs and after the application of image filters. Five Oral Radiologists measured the distance between the cementoenamel junction (CEJ) to the alveolar crest or to the deepest point of the bony defect on 12 interproximal digital radiographs of molars and bicuspids of a dry human skull. The digital manipulation and the linear measurements were obtained with the Trophy Windows software (Throphy®). For each image, six different versions were created: 1) non-manipulated; 2) bright-contrast adjustment; 3) negative; 4) negative with brightness-contrast adjustment; 5) pseudo-colored; 6) pseudo-colored with brightness-contrast adjustment. In order to prevent interpretation bias because of the repetition of measurements, the examiners measured the radiographs in a random sequence. The two-way ANOVA test at 5% level of significance to compare the means of readings of the same operator with each filter indicated p<0.05 for the majority of operators, while the comparison between the mean values of operators using the same filter indicated p>0.05 for all filters. Based on the results, we concluded that linear measurements of interproximal alveolar bone loss on digital radiographs are highly reproducible among examiners. Nevertheless, the application of image filters significantly influenced the degree of intra-examiner reproducibility. Some filters even reduced the reproducibility of intra-examiner readings.

Comparison of the reproducibility of storage phosphor and film bitewings for assessment of alveolar bone loss

OBJECTIVE

To compare bitewing storage phosphor images and a digital measuring method with bitewing films and an analog measuring method with regard to the reproducibility of measurements of alveolar bone loss.

MATERIAL AND METHODS

Nine participants randomly selected from an epidemiological study were radiographically examined using two modalities: bitewing SP images and bitewing films. A digital measuring method was used on the bitewing SP images and an analog measuring method on the bitewing films. Alveolar bone loss was measured at 12 index sites in the premolar/molar region per participant and modality. One hundred measured sites on each modality were assessed twice by three observers. Paired t-test values and intra-class correlation coefficient (ICC) were computed.

RESULTS

Comparison of the mean absolute difference of alveolar bone loss between the digital and analog measuring methods demonstrated comparable results (p=0.53). The absolute difference in millimetres between 1st and 2nd measurements was comparable for two observers and statistically different for one. Intra-observer performance between 1st and 2nd measurements was comparable for the digital (ICC=0.85) and analog (ICC=0.83) measuring methods. Inter-observer agreement for the digital measurements was higher (ICC=0.79) than for the analog measurements (ICC=0.64).

CONCLUSIONS

The study demonstrates that digital and analog measuring methods are comparable with regard to absolute alveolar bone measurements and intra-observer agreement. Inter-observer comparison demonstrated significantly higher agreement for the digital measurements. Based on the overall results, the modalities with the measuring methods utilized are comparable when measuring minor alveolar bone loss.

Measurement accuracy of marginal bone level in digital radiographs with and without color coding

OBJECTIVE

New radiographic techniques have made it possible to color-code intra-oral digital radiographs. The purpose of the present study was to compare the accuracy and precision of marginal bone level measurements in digital radiographs with and without color coding.

MATERIAL AND METHODS

Periapical digital radiographs of 21 patients were processed with and without a color-coding algorithm. The patients had periodontal surgery immediately after exposure of radiographs, and vertical distances from the cemento-enamel junction (CEJ) to the most apical part of the marginal bone were measured clinically. The measured values were considered as a reference standard and subtracted from the corresponding radiographic vertical distance. Seven observers contributed to the radiographic measurements under the same viewing conditions.

RESULTS

No statistically significant differences were found between absolute differences of vertical distances obtained from radiographs and their corresponding reference standards in the two types of radiograph. Intra- and inter-observer variability was not significant.

CONCLUSION

Color-coded digital radiographs did not provide a more favorable accuracy when assessing marginal alveolar bone levels than black-and-white radiographs and thus did not improve measurement of such levels.

Three-dimensional micro-computed tomographic imaging of alveolar bone in experimental bone loss or repair

BACKGROUND

Micro-computed tomography (micro-CT) offers significant potential for identifying mineralized structures. However, three-dimensional (3-D) micro-CT of alveolar bone has not been adapted readily for quantification. Moreover, conventional methods are not highly sensitive for analyzing bone loss or bone gain following periodontal disease or reconstructive therapy. The objective of this investigation was to develop a micro-CT methodology for quantifying tooth-supporting alveolar bone in 3-D following experimental preclinical situations of periodontitis or reconstructive therapy.

METHODS

Experimental in vivo bone loss or regeneration situations were developed to validate the micro-CT imaging techniques. Twenty mature Sprague-Dawley rats were divided into two groups: bone loss (Porphyromonas gingivalis lipopolysaccharide-mediated bone resorption) and regenerative therapy. Micro-CT and software digitized specimens were reconstructed three-dimensionally for linear and volumetric parameter assessment of alveolar bone (linear bone height, bone volume, bone volume fraction, bone mineral content, and bone mineral density). Intra- and interexaminer reproducibility and reliability were compared for methodology validation.

RESULTS

The results demonstrated high examiner reproducibility for linear and volumetric parameters with high intraclass correlation coefficient (ICC) and coefficient of variation (CV). The ICC showed that the methodology was highly reliable and reproducible (ICC >0.99; 95% confidence interval, 0.937 to 1.000; CV <1.5%), suggesting that 3-D measurements may provide better alveolar bone analysis than conventional 2-D methods.

CONCLUSIONS

The developed methods allow for highly accurate and reproducible static measurements of tooth-supporting alveolar bone following preclinical situations of bone destruction or regeneration. Future investigations should focus on using in vivo micro-CT imaging for real-time assessments of alveolar bone changes.

Marginal bone levels measured in film and digital radiographs corrected for attenuation and visual response: anin vivostudy

OBJECTIVE

To compare the accuracy and precision of measurements on marginal bone levels in differently processed digital radiographs and in film-based radiographs.

METHODS

Twenty-one patients with a diagnosis of chronic periodontitis were included in this study. Periapical radiographs were exposed with the Dixi digital intraoral radiographic system (Planmeca Oy, Helsinki, Finland) and the F-speed Film (Insight, Eastman-Kodak Co., Rochester, NY), respectively. Digital radiographs were subsequently processed into two sets: (a) correction for attenuation and visual response and (b) the same correction but with an additional shift in grey levels. Patients had periodontal surgery immediately after the radiographs were exposed. The vertical distance from cementoenamel junction to the most apical part of the marginal bone was assessed. The measurements were then employed as reference standard and subtracted by the vertical distance from radiographs accordingly. Altogether, 47 sites were evaluated. Seven observers were employed for evaluation under the same viewing conditions. ANOVA was employed for statistical analysis.

RESULTS

No significant differences were found between the absolute differences of the vertical distance obtained from radiographs to their corresponding reference standards when comparing differently processed digital radiographs, but the absolute differences were significantly smaller in digital radiographs than in films. Interobserver variances were not significant.

CONCLUSION

Digital radiographs have a favourable measurement accuracy compared with film radiographs when assessing marginal bone levels.

The infrabony defect and its determinants

BACKGROUND AND OBJECTIVE

The purpose of this study was to assess the defect width of infrabony defects in a cross-sectional study and to evaluate whether the defect width is a function of defect depth.

MATERIAL AND METHODS

Complete sets of intra-oral radiographs of patients with severe periodontitis, which exhibited at least one infrabony defect, were digitised and evaluated. The following parameters were measured: depth and width of the infrabony defect, defect angle, and width of the interdental spaces.

RESULTS

Fifty-one patients (26 women), ranging from 21 to 73 yr of age (48.5 +/- 13.4 yr), contributed a total of 1272 teeth with 135 infrabony defects (10.6%). Seventeen infrabony defects were located at sites without a neighboring tooth. Infrabony defects were statistically more prevalent in the mandible (n = 82) than in the maxilla (p = 0.013), and more prevalent at mesial sites (n = 92) than at distal sites (p < 0.001). At infrabony defects, the width of interdental spaces at the most coronal extension of the alveolar crest could be measured only at sites with neigboring teeth 2.67 +/- 0.78 mm (range: 1.19-5.70 mm). Analysis failed to reveal a statistically significant difference between defect width at sites with (2.64 +/- 0.82 mm) and sites without (2.76 +/- 0.70 mm) a neighboring tooth. Multilevel regression analysis revealed narrow defect angles to be related to deep infrabony defects, whereas width of the interdental space and distal location were related to wide defects.

CONCLUSION

Defect angle depended on defect depth and defect width was not different at sites with or without a neighboring tooth. Even in severe periodontitis, infrabony defects are found only at a minority of teeth.

Periodontal disease and coronary heart disease

BACKGROUND

Several epidemiological studies have demonstrated an association between periodontal disease and coronary heart disease (CHD). The association could be a result of confounding by mutual risk factors. The present study was undertaken in a Danish population to reveal the significance of common risk factors.

METHODS

The investigation was conducted as a case-control study comprising 250 individuals: 110 individuals with verified CHD from a Department of Cardiovascular Medicine and 140 control individuals without CHD from the Copenhagen City Heart Study. Information on diabetic status, smoking habits, alcohol consumption, physical activity, school attendance, household income, body weight and height, triglyceride, and serum cholesterol was obtained. Full-mouth probing depth (PD), clinical attachment loss (CAL), bleeding on probing (BOP), and alveolar bone level (ABL) on radiographs were registered. ABL was stratified into ABL1=ABL<or=2 mm; ABL2=ABL>2 to <or=4 mm; and ABL3=ABL>4 mm. Multiple logistic regression models with stepwise backward elimination were used allowing variables with P<0.15 to enter the multivariate analysis.

RESULTS

The CHD group had a significantly lower outcome with respect to PD, BOP, CAL, and ABL. For participants<60 years old, only risk factors such as smoking and diabetic status entered the multivariate analysis. For the ABL3 group, there was a significant association with CHD for participants<60 years old, the odds ratio being 6.6 (1.69 to 25.6). For participants>or=60 years old, there was no association.

CONCLUSIONS

The present study showed a positive association between periodontal disease and CHD in agreement with several other studies. The association was highly age dependent and could only be attributed to diabetes and smoking to some extent.

Detectability of experimental peri-implant cancellous bone lesions using conventional and direct digital radiography

BACKGROUND

The aim of this study was to compare the diagnostic performance obtained from direct digital radiographic images (in their original form and after applying a grey-scale inversion) and conventional film in the detection of artificial peri-implant cancellous bone lesions.

METHODS

Four titanium implants were placed into the cancellous bone of a dry mandible and increasingly larger bone defects were created in their approximal sites. Radiographs were taken using conventional film and a digital charge-coupled device sensor. Twelve observers estimated three series of images (conventional, digital original, digital inverse) on a 5-point confidence scale. Data were evaluated statistically by analysis of variance and the sensitivity, specificity and accuracy of the three imaging modalities were calculated.

RESULTS

Total mean observer confidence scores increased as the size of the defect also increased. No statistically significant differences were found among the three images for the absence of defect and the defect that corresponds to the smallest bur size. Significant differences were found for larger bur sizes between the conventional image and the two digital images and for the largest bur size between the digital inverse and the other two images. Specificity was high and sensitivity relatively low.

CONCLUSIONS

Peri-implant bone lesions must exceed a certain size to be confidently detected but the lesion absence is detected equally well with all three imaging modalities.

Ex vivo comparison of digital images with conventional radiographs for detection of simulated voids in root canal filling material

AIM

To compare the diagnostic potential of direct digital images with conventional radiographs for the detection of simulated root canal voids.

METHODOLOGY

The root canals of 80 extracted maxillary incisors with straight root canals were prepared and filled and the specimens divided into two groups: (i) a group of 40 teeth without voids; and, (ii) a group of 40 teeth with voids created in the root filling. Each root was imaged using the paralleling technique with a CCD-based digital system and F-speed film. Totally, there were 240 images: conventional radiographs (n = 80), digital images (n = 80) and digital zoomed images at 2x magnification (n = 80). These were interpreted for voids by a radiologist (without prior knowledge of the distribution of the voids). The reliability of the radiologist was confirmed using Cohen's Kappa Statistic, with the kappa value found to be >0.08. The sensitivity, specificity and predictive values were calculated. The differences in sensitivity and specificity between the imaging systems were then assessed using the Exact McNemar significance probability at the 95% significance level.

RESULTS

The sensitivities (95% CI) of conventional radiographs, digital images and zoomed images were 0.68 (0.57-0.78), 0.83 (0.74-0.91) and 0.80 (0.71-0.89), respectively. The specificities of the conventional radiographs, digital and zoomed images were 0.80 (0.71-0.89), 0.83 (0.74-0.91) and 0.83 (0.74-0.91), respectively. The positive predictive values (95% CI) were 0.77 (0.68-0.86), 0.83 (0.74-0.91) and 0.82 (0.74-0.90), respectively. The negative predictive values (95% CI) were 0.71 (0.61-0.81), 0.83 (0.74-0.91) and 0.80 (0.72-0.89), respectively. There were no significant differences between the sensitivity and specificity of digital images and conventional radiographs, and of digital images and zoomed images during the detection of voids in root fillings (P > 0.05).

CONCLUSIONS

Under the conditions of this laboratory study, the diagnostic performance of digital images and conventional radiographs, and between the digital images and digital zoomed images for simulated void detection in root fillings were not significantly different.

Guided Tissue Regeneration With Bioabsorbable Barriers. II. Long-Term Results in Infrabony Defects

BACKGROUND

The aim of this 5-year randomized controlled clinical trial was to evaluate the long-term results after guided tissue regeneration (GTR) therapy of infrabony defects using two bioabsorbable barriers.

METHODS

Fifteen pairs of contralateral infrabony defects in 15 patients with moderate to severe periodontitis were treated. Each patient received one polydioxanon (test: T) and one polylactide acetyltributyl citrate (control: C) barrier by random assignment. At baseline, 12, and 60 +/- 3 months after surgery clinical parameters and standardized radiographs were obtained. Vertical bone levels (PBL-V) were measured during surgery and 60 +/- 3 months later by transgingival bone sounding.

RESULTS

Thirteen patients were available for the 60-month examinations. Twelve and 60 +/- 3 months after GTR, statistically significant (P< or =0.001) vertical attachment (CAL-V) gain was found in both groups (T12: 3.5 +/- 1.5 mm; T60: 2.2 +/- 1.8 mm; C12: 4.0 +/- 0.9 mm; C60: 2.4 +/- 1.0 mm). However, from 12 to 60 months after therapy both groups experienced significant CAL-V loss (P<0.05): two defects in the test group and three in the control group had CAL-V loss >2 mm compared to the 12-month reexamination. Twelve and 60 +/- 3 months after surgery, statistically significant (P<0.05) radiographic bony fill was found in both groups (T12: 1.2 +/- 1.3 mm; T60: 1.5 +/- 2.2 mm; C12: 0.9 +/- 1.4 mm; C60: 1.0 +/- 1.6 mm). Further, 60 months after surgery significant (P<0.05) PBL-V gain was found in both groups (test: 1.8 +/- 2.3 mm; control: 2.2 +/- 1.8 mm). The study failed to show statistically significant differences between test and control regarding CAL-V and PBL-V gain 60 months after surgery.

CONCLUSION

CAL-V gain achieved after GTR therapy in infrabony defects using both bioabsorbable barriers was stable after 5 years in 21 of 26 defects (81%).

Radiographic parameters as prognostic indicators for healing of class II furcation defects

OBJECTIVE

To evaluate radiographic measurements for use as prognostic indicators for healing of class II furcation defects following regenerative therapy.

MATERIAL AND METHODS

In 17 patients (eight females), 33 class II furcation defects (mandibular buccal (n=10) and lingual (n=12), and maxillary buccal (n=11)) were treated using the barrier membrane technique. Twenty-six furcations were treated using a bioabsorbable membrane, while a nonresorbable membrane was used to treat the remaining seven furcation defects. Clinical parameters and standardized radiographs were obtained before as well as 6 and 24 months after therapy. All radiographs were digitized and evaluated by an examiner blinded to the clinical data. The following distances were measured: cemento-enamel junction line (CEJ-line) to alveolar crest (AC) at the furcation site (AC-CEJ line), CEJ-line to the furcation fornix (Fx-CEJ line), width of the furcation at the level of the AC (FW) as well as the distance from Fx to a straight line between the AC mesial and distal of the tooth (Fx-AC line).

RESULTS

Statistically significant (p<0.001) horizontal attachment gains could be observed 6 and 24 months after therapy (6 months: 1.49+/-0.85 mm; 24 months: 1.14+/-0.91 mm). However, a small but statistically significant (p=0.031) attachment loss of 0.35 mm was observed between the 6 and 24 months examination. Multilevel regression analyses identified baseline probing depth (p=0.0017) and 3 of the radiographic distances as prognostic factors: Fx-CEJ line (p=0.014), FW (p=0.0535), Fx-AC line (p=0.0827).

CONCLUSION

The analysis of presurgical radiographs may yield information on the success of the regenerative therapy of buccal and lingual class II furcation defects. A long root trunk, a wide furcation entrance and an Fx coronal to the AC have negative influences on the success of therapy. Further, a deep probing depth at the furcation site at baseline increases the likelihood for more favourable horizontal attachment gain in furcations.

Comparison of direct digital and conventional intraoral radiographs in detecting alveolar bone loss

BACKGROUND

Intraoral radiographs are important diagnostic aids in periodontics. The authors conducted a study to compare estimates of bone levels from direct digital and conventional radiographic under normal clinical use.

METHODS

A full-mouth series of conventional radiographs was taken for each of 25 subjects who had periodontitis. A long cone paralleling technique was used for periapical, or PA, images, and a paper sleeve with biting tab was employed for bitewing, or BW, images. A set of direct digital radiographs matching the conventional radiographs was taken for each subject under the same conditions. The distance from the cementoenamel junction to the interproximal alveolar crest on all readable surfaces was measured.

RESULTS

Examiners measured 857 PA image sites and 315 BW image sites matched on both radiographic systems. Paired t test showed significant differences in bone levels between the two systems. Measurements from conventional PA images were higher in all maxillary sextants (P < or = .02), and measurements from digital PA images were higher in mandibular anterior sextants (P = .007). Measurements in digital BW images were higher in mandibular posterior sextants (P = .002). A chi2 analysis of categorical bone levels (normal, early-to-moderate loss or advanced loss) showed significant differences between the imaging systems in revealing bone levels in both PA (P < .04) and BW (P < .001) images. Digital radiographs showed a higher number of sites with bone loss than did conventional radiographs.

CONCLUSIONS

Under normal clinical use, alveolar bone levels revealed on intraoral direct digital radiographs differ from those revealed on conventional radiographs.

CLINICAL IMPLICATIONS

Intraoral direct digital radiographs are not an equivalent substitute for conventional radiographs in evaluating alveolar bone levels.

Accuracy of computer-assisted radiographic measurement of interproximal bone loss in vertical bone defects

Objective. The objective of the present study was to compare 2 different computer-assisted analysis systems with respect to the measurement of interproximal bone loss on radiographs. Study Design. In 14 patients with untreated advanced periodontal disease, 90 standardized radiographs were taken presurgically and during postoperative follow-up. During periodontal surgery for 30 vertical bone defects and 28 adjacent sites (22 vertical, 3 horizontal, and 3 without bone loss), the distances from the cementoenamel junction (CEJ) to the alveolar crest (AC) and from the CEJ to the bottom of bony defect (BD) were measured. In all radiographs, the linear distances from the CEJ to the AC and from the CEJ to BD were assessed by using 2 computer-assisted analysis devices: linear measurement (LMSRT) and FRIACOM (FRIADENT, Mannheim, Germany). A comparison between the radiographic and intrasurgical assessments was performed by using the paired t test. Results. With respect to the linear distance from the CEJ to the BD, the study failed to detect statistically significant differences between the computer-assisted techniques and intrasurgical measurement as the gold standard (LMSRT,: 0.26 +/- 2.16 mm [P >.05]; FRIACOM, 0.35 +/- 2.5 mm [P >.05]). In terms of the distance from the CEJ to the BD and from the CEJ to the AC, the correlation between both computer-assisted methods was excellent (r(s) > or = 0.75) and there were no statistically significant differences detectable between LMSRT and FRIACOM for both distances. With regard to the distance from the CEJ to the AC, both techniques overestimated interproximal bone loss as compared with intrasurgical measurements (CEJ-AC, LMSRT: 1.63 +/- 2.52 mm [P <.01]; FRIACOM: 2.00 +/- 2.48 mm [P <.01]). The amount of overestimation of interproximal bone loss did not differ significantly in either computer-assisted technique (P >.05). For double measurements, both LMSRT and FRIACOM showed excellent reproducibility with coefficients of variation that ranged between 3.8% and 4.5% (CEJ-BD) and between 5.7% and 6.6% (CEJ-AC). There were no statistically significant differences between the reproducibilities of both computer-assisted techniques (P <.05). Conclusions. Both LMSRT and FRIACOM are reproducible methods to measure the distances from the CEJ to the BD and from the CEJ to the AC on radiographs and can be recommended for clinical use. With respect to the distance from the CEJ to the AC, it must be kept in mind that both computer-assisted methods tend to overestimate the real distance on an average of 1.5 to 2.0 mm.