Inter- and intra-observer agreement on Miller’s classification of gingival tissue recessions

Miller’s is the most commonly used classification of gingival tissue recessions, defined as the displacement of the soft tissue margin apical to the cemento-enamel junction. However, data on the reliability of this classification are missing so far, although reliability, which reflects the consistency of repeated measurements, is regarded as a prerequisite for judging the utility of a classification. The aim of the present study was to evaluate inter- and intra-observer agreement on Miller’s classification of gingival tissue recessions. Two hundred photographs (50 of each region: maxillary/mandibular anterior/posterior teeth) of gingival tissue recessions were evaluated twice by four observers with different degrees of experience in Miller’s classification, gingival phenotype, tooth shape, and identifiability of the cemento-enamel junction. The following inter- and intra-observer agreements were found: Miller’s classification, 0.72 and 0.73–0.95; gingival phenotype, 0.29 and 0.45–0.58; tooth shape, 0.39 and 0.44–0.59; and identifiability of the cemento-enamel junction, 0.21 and 0.30–0.59. A higher agreement was detected for anterior teeth. Further, gingival phenotype (thin-high scalloping) significantly correlated with tooth shape (long-narrow) (ρ = 0.662, p < 0.001). Miller’s classification of gingival tissue recessions was evaluated by four examiners using 200 clinical photographs and yielded substantial to almost perfect agreement, with higher agreement for anterior teeth. Although limited to photographic assessment, the present study offers the so far missing proof on the sufficient inter- and intra-observer agreement of this classification.     

Exploring the relation between patients’ resilience and quality of life after treatment for cancer of the head and neck

Resilience, which is a measure of a patient's ability to recover from a traumatic event, varies among the general population, and previous studies have suggested that it has an important influence on a patient's quality of life. We conducted a study of patients treated for cancer of the head and neck to investigate the relation between scores for resilience and quality of life (QoL). A total of 98 patients, who had been treated with curative intent, completed the University of Washington quality of life questionnaire (UW-QoL) and the Connor-Davidson resilience scale (CD-RISC). Retrospective analysis of patients’ records identified demographic data, stage of disease, and treatment. The Mann-Whitney U-test, Kruskal-Wallis test, and Spearman’s rank correlation were used to assess the significance of differences between the groups. The mean (SE) QoL score after treatment was 61 (2.081), and the mean CD-RISC score 0.427 for QoL in the last seven days. There was a significant correlation between overall scores for QoL and resilience (Spearman's Rho = 0.427, p < 0.005). As higher resilience scores had a significant correlation with a better QoL, strengthening a patient’s resilience might in turn help to improve their quality of life.     

Validation and inter‐examiner agreement of mutans streptococci levels in plaque and saliva of 10‐year‐old children using simple chair‐side tests

Since there are few validation studies of chair‐side tests of oral mutans streptococci, we compared a commercially available strip test with the conventional laboratory assay. Two plaque samples obtained from the mesial surfaces of the upper right and lower left permanent molars of sixty‐five 10‐year‐old children (boys = 38, girls = 27) were cultured and incubated using chair‐side site strip tests (Dentocult SM, Orion Diagnostica). Two plaque sampling tools, namely dental floss and micro‐brush, were compared, and inter‐examiner agreement between recordings of three examiners was assessed. Paraffin‐stimulated saliva was then collected for laboratory and chair‐side assays. The plaque and saliva chair‐side tests correlated well with each other (Spearman rho, r=0.72) and with the laboratory method, showing coefficients of 0.76 and 0.80 for saliva and plaque, respectively. Compared to the laboratory method, the sensitivity (Sn), specificity (Sp), accuracy (A), and kappa (K) values of the salivary and plaque chair‐side tests were 0.63, 0.75 (Sn), 0.93, 0.90 (Sp), 0.82, 0.85 (A), and 0.58, 0.66 (K), respectively. Agreement between the two plaque sampling techniques was good (0.91). Inter‐examiner agreement of plaque scores ranged between 0.65 and 0.86 when all density categories were analysed separately; when dichotomized into low and high categories, complete agreement was found. Agreement between the plaque and saliva chair‐side tests and the laboratory salivary assay was good, and in terms of sensitivity, accuracy, and kappa values, the site strip plaque test surpassed the salivary chair‐side test.     

The relationship between various parameters of complete denture quality and patients’ satisfaction

BackgroundPatients’ appreciation of their conventional complete dentures might be affected by the quality of the dentures.MethodsA random sample of 33 edentulous patients who were rehabilitated by means of conventional complete dentures participated in the study. Three independent investigators who underwent technique calibration evaluated the dentures on the basis of seven clinical criteria by using a validated examination form. The patients filled out a validated denture satisfaction scale. The author used Pearson product-moment correlation and analysis of covariance to identify possible correlations.ResultsThe study results showed that most patients were between “reasonably satisfied” and “very satisfied” with their dentures. The author found nominally higher satisfaction among those receiving both mandibular and maxillary dentures and significant positive correlations between the overall denture satisfaction score and the stability of the mandibular denture (P = .039) and retention of the mandibular denture (P = .005). In contrast, esthetic lip support and lower lip line, occlusion, and maxillary stability and retention were not correlated with participants’ overall satisfaction level (P > .064).ConclusionsThe results of this study show that a clinically stable mandibular denture was the most important determinant of patients’ satisfaction.Practical ImplicationsThe study findings highlight the most important denture quality parameters that can aid clinicians in meeting their patients’ expectations.     

Comparison of Fit Accuracy between Procera® Custom Abutments and Three Implant Systems

Background: Although increase of misfit has been reported when associating implant and abutment from different manufacturers, Procera custom abutment has been universally used in clinical practice. Purpose: The purpose of this investigation was to compare the vertical gap of zirconia Procera® abutment associated with implants from the same manufacturer (Procera manufacturer) and two other implant systems. Materials and Methods: Twenty‐four zirconia Procera abutments were produced using computer‐assisted design and manufacture and paired with (a) eight MK III, RP 4.1 × 10 mm implants (Nobel Biocare?, Göteborg, Sweden) – GNB group (Nobel Biocare group); (b) eight Try on, 4.1 × 10 mm implants (Sistema de Implantes, São Paulo, Brazil) – ES group (SIN experimental group) ; and (c) eight Master screw, 4.1 × 10 mm implants (Conexão® Sistema de Prótese, São Paulo, Brazil) – EC group (Conexão experimental group). A comparison of the vertical misfit at the implant–abutment interface was taken at six measuring sites on each sample using scanning electron microscopy with a magnification of 408×. One‐way analysis of variance was used to test for differences, and Tukey's test was used for pair‐wise comparison of groups (α = 0.05). Results: Significant differences relative to average misfit were found when Procera abutments were associated with other implant manufacturers. The ES group and EC group did not differ significantly, but both demonstrated significantly larger average misfit than the GNB group (p = .001). The average misfit was 5.7 µm ± 0.39, 9.53 µm ± 0.52, and 10.62 µm ± 2.16, respectively, for groups GNB, ES, and EC. Conclusion: The association of Procera zirconia abutment with other implant systems different from its manufacturer demonstrated significant alteration of vertical misfit at implant–abutment interface.     

Correlation between degree of conversion,resin–dentin bond strength and nanoleakage of simplified etch-and-rinse adhesives

Objectives

The aim of this study was to correlate the degree of conversion measured inside the hybrid layer (DC) with the microtensile resin–dentin bond strength (μTBS) and silver nitrate uptake or nanoleakage (SNU) for five simplified etch-and-rinse adhesive systems.

Methods

Fifty-five caries free extracted molars were used in this study. Thirty teeth were used for μTBS/SNU [n = 6] and 25 teeth for DC [n = 5]. The dentin surfaces were bonded with the following adhesives: Adper Single Bond 2 (SB), Ambar (AB), XP Bond (XP), Tetric N-Bond (TE) and Stae (ST) followed by composite resin build-ups. For μTBS and SNU test, bonded teeth were sectioned in order to obtain stick-shaped specimens (0.8 mm²), which were tested under tensile stress (0.5 mm/min). Three bonded sticks, from each tooth, were not tested in tensile stress and they were immersed in 50% silver nitrate, photo-developed and analyzed by scanning electron microscopy. Longitudinal 1-mm thick sections were prepared for the teeth assigned for DC measurement and evaluated by micro-Raman spectroscopy.

Results

ST showed lowest DC, μTBS, and higher SNU (p < 0.05). All other adhesives showed similar DC, μTBS, and SNU (p > 0.05), except for TE which showed an intermediate SNU level. The DC was positively correlated with μTBS and negatively correlated with SNU (p < 0.05). SNU was also negatively correlated with μTBS (p < 0.05).

Significance

The measurement of DC inside the hybrid layer can provide some information about bonding performance of adhesive systems since this property showed a good correlation with resin–dentin bond strength and SNU values.     

Relationship between fracture of mandibular condyle and absence of unerupted mandibular third molar—a retrospective study

Purpose

The purpose of the present study was to find, if there exists, a co-relation between presence of unerupted mandibular third molar and fracture of mandibular condyle.

Methods

A retrospective, multicenter study was done collecting the data of all mandibular condyle fractures treated from November 2006 till August 2015. Data was collected from the patient’s records and radiographs for the following information: age, sex, etiology of fracture, presence and state of lower third molars, and associated fracture. The results were subjected to statistical analysis.

Results

Out of 180 patients of condylar fracture, unerupted third molars were present in 35 (19.44 %) cases compared to 145 (80.55 %) cases of condylar fracture where the unerupted third molars were not present. The difference was statistically significant (p < 0.05). In the unerupted third molar present group, isolated bilateral condylar fracture was seen in 4 (11.4 %) cases, bilateral condylar fracture associated with other mandibular fractures in 9 (25.7 %) cases, isolated unilateral condylar fracture in 0 (0.0 %) cases, and unilateral condylar fracture associated with other mandibular fractures in 17 (48.5 %) cases and condylar fracture associated with mid face fractures in 5 (14.2 %) cases. In the unerupted third molar absent group, isolated bilateral condylar fracture was seen in 5 (3.4 %) cases, bilateral condylar fracture associated with other mandibular fractures in 30 (20.6 %) cases, isolated unilateral condylar fracture in 24 (16.5 %) cases, unilateral condylar fracture associated with other mandibular fractures in 73 (50.34 %) cases, and condylar fracture associated with mid face fractures in 13(8.96 %) cases. The difference between the groups was statistically significant (p = 0.032).

Conclusion

This study suggests that the fractures of mandibular condylar region have a significantly higher incidence in patients without an unerupted mandibular third molar.

     

Relation between mercury and Alzheimer's disease?

Mercury from dental silver amalgam has been suggested to be linked with Alzheimer's disease. The percentage in the population (formerly) possessing amalgam restorations exceeds that of Alzheimer patients. Therefore, low levels of mercury in the brain are unlikely to cause the disease. However, studies indicating increased levels of mercury in Alzheimer brains compared to controls have been criticised. In contrast, it has been proven that an inherited trait accounts for a minor proportion of Alzheimer's patients. Moreover, education--or related psychosocial factors--instead of amalgam has been found to be associated with the disease. Therefore, it does not seem warranted as yet to conclude that mercury is an etiological factor in Alzheimer's disease.     

Association between Björk's structural signs of mandibular growth rotation and skeletofacial morphology

The aim of this study was to apply Bj?rk's structural signs of mandibular growth rotation to answer the questions: (1) Is a hyperdivergent or hypodivergent skeletofacial growth pattern characterized by a specific mandibular morphology? (2) Are severe skeletofacial hyperor hypodivergencies recognized more easily than mild ones? (3) Are skeletofacial hyper- or hypodivergencies recognized more easily in older than in younger subjects? Mandibular cuttings from lateral head films of 135 Class I or Class II subjects were surveyed twice by nine observers. Of the 135 subjects, 95 subjects exhibited a large (ML/NSL > 38 degrees) and 40 a small (ML/NSL < 26 degrees) mandibular plane angle. Using the structural signs of mandibular growth rotation, the observers had to categorize the subjects as having either a high-angle or low-angle skeletofacial morphology. In 14% (13 of 95) of the subjects with a large ML/NSL angle, the skeletofacial hyperdivergency was recognized in all registrations, but in 19% (18 of 95), the hyperdivergency was identified in less than half of the registrations. In 63% (25 of 40) of the subjects with a small ML/NSL angle, the skeletofacial hypodivergency was recognized in all registrations, whereas in only 2.5% (one of 40), the hypodivergency was identified in less than half of the registrations. There was no association between the degree of hypo- or hyperdivergency or the age of the subjects and the number of correct registrations. Using the structural method of Bj?rk, it was difficult to categorize the subjects as having either a hyperor hypodivergent skeletofacial morphology. However, hypodivergency was recognized more easily than hyperdivergency.     

A clinical investigation of the relationship between the quality of conventional complete dentures and the patients’ quality of life

Objective

The purpose of this study was to determine whether there is a correlation between the clinical quality of conventional complete dentures and patient quality of life.

Materials and methods

This study included a random sample of 32 completely edentulous patients (15 males and 17 females) who were treated with conventional complete dentures. Using a validated questionnaire, three investigators evaluated the dentures independently on the basis of seven clinical parameters: esthetics (lip support and lower lip line), retention and stability of the maxillary and the mandibular dentures, and occlusion. Patients completed the validated Oral Health Impact Profile-20 (OHIP-20) questionnaire. Correlations were determined by using the point-biserial correlation coefficient.

Results

Clinicians rated the overall clinical quality of the dentures satisfactory in 80.3% of patients. The mean (±standard deviation) total OHIP-20 score was 56.3 ± 15.9 out of a possible 120 maximum. A statistically significant negative correlation was found between the stability of the maxillary and mandibular dentures and the total OHIP-20 score (p = 0.009 and 0.0023, respectively). A negative correlation between the total OHIP-20 score and the retention of the mandibular denture approached significance (p = 0.092). Esthetics, retention of the maxillary denture, and occlusion were not correlated with patient quality of life (p > 0.169).

Conclusion

Stability of the maxillary and mandibular dentures is the denture quality parameter that can most significantly affect patient quality of life.