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.

Oral disorders in patients with newly diagnosed haematological diseases

OBJECTIVE

This study aimed to examine saliva flow rates and prevalence of dental and periodontal diseases of patients with newly diagnosed severe haematological diseases and compare these findings with age-matched controls of normal population.

METHODS

A total of 149 patients diagnosed with haematological diseases aimed to be treated with haematological stem cell transplantation between 2008 and 2018 and 154 controls were included in the study. A dental examination was performed for patients within a maximum of 6 months after diagnosis. Differences were compared in terms of the stimulated salivary flow rate (SSFR); decayed, missing and filled teeth (DMFT) index; number of teeth; caries prevalence; presence of periodontitis and acute infections.

RESULTS

The mean SSFR of the patient group was significantly lower (1.1 ml/min ± 0.7 ml/min) than the mean SSFR of the controls (1.3 ml/min ± 0.5 ml/min; p = 0.004). The number of caries lesions was significantly higher in the patient group (mean ± SD, 1.1 ± 1.9) than in the control group (mean ± SD, 0.4 ± 1.2; p < 0.001). There were fewer teeth and a higher DMFT index in the patient group compared to the control group, but the differences were not significant. Acute symptomatic infections were observed in eight (5.4%) patients and in none of the controls (p < 0.01).

CONCLUSIONS AND CLINICAL RELEVANCE

Oral examinations in patients with newly diagnosed severe haematological disease demonstrated a higher prevalence of caries, acute infections and lower mean SSFR compared with the controls. These findings support the recommendations for early dental examination at the time of diagnosis.

Initial management of dental trauma: musts, shoulds, and cans

When dental trauma occurs, initial management on the day of injury has a determining influence on healing and thus on the prognosis of the affected teeth. Improper, delayed, and/or inconsistent treatment often has far-reaching consequences that cannot be reversed later, even with great effort, especially in children and adolescents. In most cases, it is unrealistic or impossible for the patient to get to a specialized dental trauma facility in time. Therefore, it is every dental practitioner's duty to provide adequate initial diagnosis and treatment of dental trauma at their dental practice, even if they do not have routine experience in this area. This article serves as a guide to the initial management of dental trauma. It utilizes a three-tiered approach to illustrate which initial management measures are absolutely essential (MUSTS), which should ideally be performed (SHOULDS), and which are not top priorities but can be performed (CANS) if the necessary time, training and experience, and equipment and facilities are available. For further treatment, dental practitioners should realistically assess the limits of their ability to treat complex dental trauma cases and, if necessary, they should refer the patient to a specialist or specialized treatment center. (Quintessence Int 2020;51:763-774; doi: 10.3290/j.qi.a45103; modified from a previously published article (in German) Quintessenz 2019;70(9):990-1002).

Endodontic Treatment in Switzerland. A National Survey

The purpose of this study was to collect information about current treatment protocols of endodontic procedures among general practitioners (GP), endodontically interested practitioners (EI) and endodontic specialists (ES) in Switzerland and to compare them with available endodontic quality guidelines and former surveys. A questionnaire was distributed to 1,522 attendees of two national conferences (Swiss Dental Association, 2015; Swiss Society for Endodontology, 2016) addressing socio-demographic characteristics and specific questions about root canal treatments (RCT) including techniques and materials used. Five hundred and six surveys were collected comprising data of 81.8% GP, 14.4% EI and 3.8% ES (response rate: 33.2%). The majority of respondents was male (59.9%), 40–59 years old (55.9%) with >20 years of clinical experience (54.3%). 498 participants (98.4%) stated to perform RCT. Rubber dam was always used in 52.2% of GP, 69.9% of EI and 89.5% of ES, while never-user accounted for 14.1%. Overall, 63.9% used loupes and 13.7% microscopes (mostly by ES). Rotating instruments were selected in 43.2%, followed by conventional hand-instruments (37.8%) and reciprocating instruments (19%). GP rarely activated irrigants and applied NaOCl in lower concentrations (>0.5–1%) compared to ES. GP preferred lateral compaction (57%), ES performed vertical compaction in 89.5%. 92% completed RCT after two or more visits. The majority of dentists in Switzerland follow the available quality guidelines and the present findings are coherent with internationally published surveys. Nonetheless, discrepancies are still present between daily practice and endodontic quality guidelines, especially with the routine use of rubber dam and working length determination, predominantly within the endodontic non-specialists.

Influence of Pretreatment Methods on the Adhesion of Composite and Polymer Infiltrated Ceramic CAD-CAM Blocks

PURPOSE

To assess the effect of different surface pretreatments on the shear bond strength of resin luting material on CAD-CAM composite resins and a polymer-infiltrated ceramic network (PICN).

MATERIALS AND METHODS

CAD-CAM materials (Brilliant Crios, Cerasmart, Lava Ultimate, VITA Enamic) were subjected to the following pretreatments: no pretreatment; grit blasting; grit blasting + silane; HF etching + silane; tribochemical silica coating + silane; manufacturers' specifications; manufacturers' specifications + silane; manufacturers' specifications using only the manufacturers' products including their recommended luting materials (DuoCem, G-Cem LinkForce, RelyX Ultimate, RelyX Unicem 2). Specimens were luted with resin luting material according to the Swiss shear test design. After six months of water storage, shear bond tests were performed. Data were analyzed with multiple linear regression models and nested models (α = 0.05).

RESULTS

Low bond strengths were obtained without pretreatment (Brilliant Crios 3.01 ± 0.54 MPa, Cerasmart 2.66 ± 0.47 MPa, Lava Ultimate 1.76 ± 0.26 MPa, VITA Enamic 2.83 ± 0.63 MPa). Grit blasting achieved high bond strengths across all materials (Brilliant Crios 5.17 ± 0.77 MPa, Cerasmart 4.27 ± 0.50 MPa, Lava Ultimate 3.98 ± 0.54 MPa, VITA Enamic 4.97 ± 0.90 MPa). Silane application tended to decrease bond strengths on CAD-CAM composite resins. Following the manufacturers' specifications and using their recommended materials achieved the highest bond strengths for all materials except Cerasmart (Brilliant Crios 5.75 ± 0.91 MPa, Cerasmart 2.82 ± 0.28 MPa, Lava Ultimate 6.63 ± 0.97 MPa, VITA Enamic 7.09 ± 0.77 MPa).

CONCLUSION

Grit blasting and the application of a suitable material primer is a useful pretreatment for the bonding of CAD-CAM composite resins. Silane application on CAD-CAM composite resins may entail drawbacks, possibly owing to the scarcity of silanizable fillers.

Fluorescence-aided Composite Removal in Directly Restored Permanent Posterior Teeth

AIM

The aim of this study was to quantitatively compare conventional composite removal and composite removal supported by the fluorescence-aided identification technique (FIT) regarding the completeness, selectivity, and duration of the procedure in directly restored permanent posterior teeth.

METHODS AND MATERIALS

Two operators removed standardized direct class II composite restorations (n=32 per operator) in human tooth models under simulated clinical conditions. According to a randomized allocation scheme, removal was performed with either the conventional technique (contra-angle handpiece) or supported by FIT. The duration of each removal procedure was recorded. The completeness and selectivity were volumetrically assessed through superimposition of three-dimensional surface scans. Statistical significance was tested by examining the overlap of 95% confidence intervals (CI). Multiple comparison was performed with Tukey tests for each variable.

RESULTS

Compared with the conventional technique, composite removal with FIT was faster (329 seconds [95% confidence interval (CI): 268-390 seconds] vs 179 seconds [95% CI: 150-208 seconds]), generated less tooth substance loss (4.53 mm³ [95% CI: 3.77-5.30 mm³] vs 2.77 mm³ [95% CI: 2.11-3.43 mm³]), and left behind less composite residue (1.58 mm³ [95% CI: 1.23-1.94 mm³] vs 0.53 mm³ [95% CI: 0.39-0.67 mm³]).

CONCLUSION

Within the limitations of this in vitro study, FIT facilitated the selective and expeditious removal of tooth-colored composites in directly restored posterior teeth.

Common oral diseases in allogeneic haematopoietic stem cell transplantation (HSCT) recipients pre-HSCT

OBJECTIVES

The purpose of this study was to compare the prevalence of common oral diseases between allogeneic haematopoietic stem cell transplantation (HSCT) recipients and healthy controls.

MATERIALS AND METHODS

A total of 143 adult allogeneic HSCT recipients who were treated for haematological malignancies between 2008 and 2016 were included in the study. The HSCT recipients were age and sex matched with healthy controls. A dental examination was performed on the HSCT recipients prior to HSCT. Differences in stimulated saliva flow rate (SSFR), decayed, missing and filled teeth (DMFT) index, number of teeth, number of caries lesions, and measures of current or previous periodontitis (radiological attachment loss >3 mm or probing pocket depth ≥4 mm) between HSCT recipients and controls were examined.

RESULTS

Stimulated saliva flow rate, DMFT index and the number of caries lesions were poorer in the HSCT recipients pre-HSCT compared to controls (all P-values <0.05). No statistically significant differences in the measures of current or previous periodontitis were observed.

CONCLUSIONS

Stimulated saliva flow rate was low and caries was common in HSCT recipients prior to HSCT. Efficient preventive strategies are important in order to maintain the oral health of these patients.

Evaluation of a Fluorescence-aided Identification Technique (FIT) for removal of composite bonded trauma splints

BACKGROUND/AIM

Accurate removal of composite bonded titanium trauma splints (TTS) can be challenging. The aim of this study was to evaluate a Fluorescence-aided Identification Technique (FIT) compared with a conventional light source (CT) for removal of trauma splints regarding loss of tooth substance, residual composite, and time taken.

MATERIALS AND METHODS

Twenty maxillary models with six bovine teeth (13 - 23) were fabricated. An optical three-dimensional impression was taken and a TTS was applied from 12 to 22 with two bonding sites on every tooth under standardized conditions using an etch-and-rinse adhesive and resin composite. Two operators removed 10 splints each (5x FIT and 5x CT). For FIT, a 405 nm light-emitting headlamp was used. Time was recorded. A post-operative scan was superimposed on the pre-operative scan using OraCheck software. A qualitative and quantitative analysis of tooth defects and composite remnants was performed by two operators and statistically analyzed.

RESULTS

Compared with the CT, FIT led to significantly fewer and smaller enamel defects (mean volume: -0.04 mm³ vs -0.33 mm³ ) (P < 0.001), significantly less composite remained (mean volume: 0.02 mm³ vs 0.28 mm³ ) (P < 0.001), and the removal procedure with FIT was significantly quicker (mean: 162 seconds vs 268 seconds) (P < 0.001), CONCLUSIONS: FIT facilitated the removal of composite used to bond trauma splints leading to less time-consuming as well as less invasive treatment. It left fewer composite residues on enamel surfaces.

Changes in periapical status, quality of root fillings and estimated endodontic treatment need in a similar urban German population 20 years later

OBJECTIVES

The study aimed at assessing, as primary objective, the periapical status and quality of root fillings, and, as secondary objective, the endodontic treatment need of a German urban population in a cross-sectional study 20 years after the first one.

MATERIALS AND METHODS

Clinical and radiographic data of 353 patients were evaluated. Descriptive and regression analyses were performed and the endodontic treatment need was calculated. Results were compared with data from the year 1993.

RESULTS

A total of 9269 teeth were examined (26.2 teeth per patient; 1993, 24.4), of which 337 teeth were root filled (3.6%; 1993, 2.7%). Prevalence of apical periodontitis in root-filled teeth was 34% (1993, 61%). Quality of root fillings was adequate in 117 cases (35%; 1993, 14%). Minimum endodontic treatment need was estimated with 1.6% (1993, 2.3%), including teeth with clinical symptoms. Considering symptomless teeth with apical periodontitis and poor quality of root filling, the treatment need was 2.9% (1993, 3.7%). Regression analysis identified quality of root filling as a significant factor for periapical health (p = 0.01, odds ratio 3.4×, 95% CI 1.9-6.3×), likewise the type of instrumentation. Teeth treated with rotary files had a significantly better outcome (p = 0.02, odds ratio 2.0×, 95% CI 1.1-3.7×).

CONCLUSIONS

Quality of root fillings and the periapical status have improved over the last 20 years in Germany. However, there is still a need for an increase in quality of root canal treatment.

"Karius and Baktus": A Critical Appraisal of Enger's Seminal Storybook

Karius and Baktus, first published in 1949, is one of the most influential storybooks with dental caries as main theme and it remains in wide use for domestic health education. This study aimed at assessing oral health related contents of the historic storybook in the light of the current body of cariologic evidence. Two investigators independently identified phrases in the storybook with cariologically relevant content. Dental health related contents were systematically evaluated with respect to the current body of cariologic evidence. Karius and Baktus highlights important etiopathogenetic and preventive aspects such as sugars consumption and tooth brushing with toothpaste. Its behavior management techniques and narrative health didactics concerning dental care for children are, however, outmoded. The cariologic core statements in Karius and Baktus have remained valid whereas certain narrative features may have some drawbacks when employing the historic storybook for educational purposes for young children.

Adhesive bonding to polymer infiltrated ceramic

Aim of this study was to investigate the mechanism of adhesive bonding to the polymer-infiltrated ceramic VITA Enamic [VE]. Shear bond strength was measured with three resin composite cements: RelyX Unicem 2 Automix, Clearfil SA and Variolink II on polished surfaces of VE and its components silicate ceramic [SC] and polymer [PM] (n=12). Further, the effect of etching VE with 5% HF for 15-240 s and the application of silane coupling agents was analyzed in a screening test (n=6). Shear bond strength measurements were performed after 24 h of water storage at 37°C. Significant bonding to polished substrates could only be achieved on VE and SC when silane coupling agents were used. Etching of VE with 5% HF increased shear bond strength. Following silanization of etched VE, a further increase in shear bond strength could be established. Etching for more than 30 s did not improve shear bond strength.

Partial Ceramic Crowns Prepared by Dental Students: Clinical Performance Up to Five Years

Partial ceramic crowns (PCCs) are an accepted treatment option for the restoration of posterior teeth with deficient tooth substance. Data on the survival of PCCs fabricated by dental students are scarce. The aim of this retrospective clinical study was to investigate the clinical performance and longevity of PCCs placed by dental students in the last year of their training program at the University of Basel, Switzerland. Eighty-eight patients who had received at least one PCC (n=108) in the program were considered for clinical assessment; their records were analyzed to detect previous complications or failures; and they were contacted by telephone. Criteria regarding aesthetic, functional, and biological aspects were rated with a scoring system from 1=clinically excellent to 5=clinically poor. The response rate was 66.3% (55 of 83 included patients), and 72.2% (n=78) of the PCCs were included in the analysis. Five PCCs had been lost within ten to 78 months after treatment. Six PCCs were recorded as failures (score 5), and ten received clinically unsatisfactory gradings (score 4). The risk of a clinically poor outcome was 14% after five years (86% survival), while the overall success rate was 63.5%. These results suggest that the clinical procedure of PCCs was successfully implemented by these students with satisfactory clinical survival.

Accuracy of a separating foil impression using a novel polyolefin foil compared to a custom tray and a stock tray technique

PURPOSE

To compare the dimensional accuracy of three impression techniques- a separating foil impression, a custom tray impression, and a stock tray impression.

MATERIALS AND METHODS

A machined mandibular complete-arch metal model with special modifications served as a master cast. Three different impression techniques (n = 6 in each group) were performed with addition-cured silicon materials: i) putty-wash technique with a prefabricated metal tray (MET) using putty and regular body, ii) single-phase impression with custom tray (CUS) using regular body material, and iii) two-stage technique with stock metal tray (SEP) using putty with a separating foil and regular body material. All impressions were poured with epoxy resin. Six different distances (four intra-abutment and two inter-abutment distances) were gauged on the metal master model and on the casts with a microscope in combination with calibrated measuring software. The differences of the evaluated distances between the reference and the three test groups were calculated and expressed as mean (± SD). Additionally, the 95% confidence intervals were calculated and significant differences between the experimental groups were assumed when confidence intervals did not overlap.

RESULTS

Dimensional changes compared to reference values varied between -74.01 and 32.57 µm (MET), -78.86 and 30.84 (CUS), and between -92.20 and 30.98 (SEP). For the intra-abutment distances, no significant differences among the experimental groups were detected. CUS showed a significantly higher dimensional accuracy for the inter-abutment distances with -0.02 and -0.08 percentage deviation compared to MET and SEP.

CONCLUSION

The separation foil technique is a simple alternative to the custom tray technique for single tooth restorations, while limitations may exist for extended restorations with multiple abutment teeth.

Lower Educational Level is a Risk Factor for Tooth Loss - Analysis of a Swiss Population (KREBS Project)

PURPOSE

To analyse risk factors for tooth loss in women and men seeking treatment at the University of Basel, Switzerland.

MATERIALS AND METHODS

Records of patients from the pool of patients at the department were consecutively screened between January 2009 and October 2011. Gender, smoking habits, education, profession, general health status and dental variables were recorded. Tooth loss was assessed on full-mouth periapical radiographs. Gender-nested logistic regression models were applied for statistical analysis.

RESULTS

The sample consisted of 161 participants (4012 teeth in total, 3988 after exclusion of third molars), 80 women and 81 men, with a mean age of 48.0 ± 14.6 in women and 47.7 ± 12.5 in men. There were no significant differences in smoking status between men and women. Oral clinical data revealed similar gingival inflammation (BI) and number of sites with a periodontal probing depth (PPD) ≥ 5 mm among men and women. However, oral hygiene (PI) differed between men and women, with women having better oral hygiene (p < 0.01). Tooth loss increased from the front to the molar regions. A significant risk for tooth loss was associated with decreasing educational level. Compared to advanced education, individuals with 'no school graduation' showed a significantly higher risk for tooth loss in women (OR = 3.2, p = 0.02) and men (OR = 3.6, p = 0.03). Age ≥ 50 years significantly predicted tooth loss in men only (OR 2.2, p = 0.01).

CONCLUSION

The results from the present study demonstrate lower educational level as a strong risk factor for tooth loss in this Swiss cohort. The educational level may need to be considered for diagnosis and treatment planning, and particularly for patient information practices to increase the patients' understanding of the development of oral diseases leading to tooth loss.

Presence of root canal treatment has no influence on periodontal bone loss

AIM

The aim of this study was to compare the interproximal bone level at root canal-filled teeth and non-root canal-filled teeth.

MATERIALS AND METHODS

The records of patients from the department were consecutively screened from January 2009 to October 2011. The distance between the coronal reference point to the alveolar bone crest (AC) was assessed at the mesial and distal aspects of root canal-filled teeth (RCF+) and their contralateral non-root canal-filled teeth (RCF-) on periapical radiographs. Generalised linear mixed-effects models were applied.

RESULTS

The sample consisted of 128 pairs of teeth comprising data from 72 patients. The results for AC revealed a median distance of 3.2 mm for RCF+ and 3.4 mm for RCF- (p = 0.61). Using the maximal distance on either the distal or the mesial tooth surface, a median distance of 3.6 mm was detected for RCF+ and 3.8 mm for RCF-, respectively (p = 0.42). Even after taking several tooth- and subject-specific variables into account, the differences between AC on RCF+ and RCF- were statistically not significant (p > 0.05).

CONCLUSION

The interproximal bone loss did not differ statistically significant between root canal-filled teeth and non-root canal-filled teeth.

CLINICAL RELEVANCE

Existence of appropriately done root canal fillings in periodontitis patients has no effect on the prognosis of periodontal disease.

Do periapical and periodontal pathologies affect Schneiderian membrane appearance? Systematic review of studies using cone-beam computed tomography

OBJECTIVES

This systematic review analyzed the relationship between periapical and periodontal pathologies in the posterior maxilla and the appearance of the Schneiderian membrane in cone-beam computed tomography (CBCT) compared with sound dentitions.

METHODS

Five electronic databases (Cochrane Library, Embase, OpenGrey, PubMed, Web of Science), complemented by hand searching, were screened up to May 9, 2016. Human clinical studies that used CBCT and contained information on the periapical/periodontal status in the posterior maxilla and Schneiderian membrane appearance were included. A weighted vote counting (WVC) method was applied to summarize results across studies.

RESULTS

Out of 413 records, 20 studies were included. In the WVC, the studies that observed a positive association between periapical lesions and the appearance of the Schneiderian membrane outweighed those that found no such association (WVC 51 % and WVC 33 %, respectively), with some studies yielding indeterminate results (WVC 16 %). Regarding the relation between periodontal pathologies and the appearance of the Schneiderian membrane, WVC produced a tie between studies demonstrating a positive association (WVC 46 %) and those showing no association (WVC 44 %); one study (WVC 10 %) reported indeterminate results.

CONCLUSIONS

On CBCT scans, periapical lesions in the posterior maxilla are likely to be associated with Schneiderian membrane thickening. In contrast, current evidence regarding the relation between periodontal diseases and the appearance of the Schneiderian membrane in CBCT is inconclusive.

CLINICAL RELEVANCE

Incidental maxillary sinus findings on CBCT scans warrant thorough differential diagnosis. Frequently, they may be related to dental pathologies.

Treatment of calcified root canals in elderly people: a clinical study about the accessibility, the time needed and the outcome with a three-year follow-up

OBJECTIVE

Determination of accessibility, time needed and outcome of endodontic treatment of teeth with calcified root canals in a sample of elderly participants in a private practice limited to endodontics.

BACKGROUND

Due to demographic changes, gerodontology is becoming more and more important, also in the field of endodontology. Elderly patients can show up with severe calcifications of root canals. Root canal treatment, when needed, can be very challenging in these cases. Only few data exist about the treatment of calcified root canals and its outcome, especially in an elderly population.

MATERIALS AND METHODS

Forty-one participants (median age: 72 years) needing a root canal treatment were included. The total number of treated teeth was 41 with 114 negotiated root canals. A specialist limited to endodontics performed the treatment in a private practice. Outcome was assessed by applying the periapical index score on the basis of recall radiographs provided by the referring dentists. Likewise, time required to localise the root canals was measured.

RESULTS

All root canals have been detected using the operating microscope, and full working length could be established in 90% of the cases. Success rate was 80% after an observation time of 3 years. In three of five teeth, root canals could be localised within 15 min.

CONCLUSION

Calcified root canals of older people treated in this study were all accessible within a maximum of 60 min. The success rate after a follow-up of 3 years was 80%.