Comparison of mechanical and surface properties of two 3D printed composite resins for definitive restoration.

STATEMENT OF PROBLEM: Additive manufacturing (AM) technology is emerging as an innovative approach in the dental field. In recent years, manufacturers have introduced 3-dimensionally printed composite resins (3D-CRs) that are specifically designed for the AM of definitive prostheses; however, the mechanical and surface properties of these materials require investigation. PURPOSE: The purpose of this in vitro study was to assess and compare the mechanical and surface properties of 2 commercially available 3D-CRs for definitive restoration after artificial aging. MATERIAL AND METHODS: Saremco print Crowntec; Saremco Dental AG and Varseo Smile Crown Plus; Bego GmbH were printed with a layer thickness of 50 µm at a 90-degree angle. A total of 20 bar-shaped specimens (25×2×2 mm) were produced from each material to measure the flexural strength (σf) and elastic modulus (E) using a 3-point bend test, and 5 disk-shaped specimens (Ø15×3 mm) from each material were used to measure the surface microhardness using a microhardness test. Half of the specimens were tested under dry conditions, while the other half were immersed in distilled water for 30 days. Five disk-shaped specimens (Ø15×3 mm) from each material were used to evaluate surface roughness before and after undergoing toothbrushing simulations. Additionally, 5 disk-shaped specimens (Ø15×1 mm) were used to assess water sorption (wsp) and solubility (wsl) over 28 days. Statistical analyses were conducted using the Wilcoxon matched-pairs signed-rank test (1-tailed) with 90% power (α=.05). RESULTS: The mean ±standard deviation flexural strength values were 123.4 ±8.7 MPa for Saremco print Crowntec and 109.9 ±15.8 MPa for Varseo Smile Crown Plus. After aging, these values were 97.5 ±15.2 MPa for Saremco print Crowntec and 94.2 ±11.7 MPa for Varseo Smile Crown Plus. The mean Vickers hardness values were 33.2 ±0.8 N/mm2 for Saremco print Crowntec and 31.5 ±0.6 N/mm2 for Varseo Smile Crown Plus. After aging, the mean values were 31.7 ±0.9 N/mm2 for Saremco print Crowntec and 29.6 ±1.0 N/mm2 for Varseo Smile Crown Plus. The mean modulus of elasticity was 4.2 ±0.3 GPa for Saremco print Crowntec and 3.82 ±0.2 GPa for Varseo Smile Crown Plus. After 21 days, the mean sorption values were 11.52 ±0.6 mg/mm3 for Saremco print Crowntec and 12.43 ±0.4 mg/mm3 for Varseo Smile Crown Plus. After 28 days, the mean solubility values were 1.36 ±0.4 mg/mm3 for Saremco print Crowntec and 0.98 ±0.3 mg/mm3 for Varseo Smile Crown Plus. Significant differences were found between the 2 3D-CRs in flexural strength in the dry state (P=.03), in Young modulus after 30 days of water immersion (P=.023), and in Vickers hardness in the dry state (P=.01) and after 30 days of water immersion (P=.018). CONCLUSIONS: Both 3D-CRs provided good in vitro performance and the mechanical properties required for long-term clinical application. Artificial aging decreased the flexural strength of both 3D-CRs.

"Diagnostic ability in oral pathology among different population clusters".

OBJECTIVES: To assess the diagnostic ability in detecting oral lesions among dentists, dental hygienists, dentistry students, oral hygiene students, and non-healthcare subjects. MATERIALS AND METHODS: Participants were invited to classify 30 images of oral lesions in "benign" or "suspected malignant" only based on the visual appearance of the lesion. Diagnostic accuracy was assessed by calculating sensitivity and specificity with 95% confidence intervals and stratified by population group and image features (color, shape, and size of the lesions). RESULTS: A total of 16,590 examinations by 553 subjects were analyzed. Overall sensitivity and specificity were 57% (95% confidence interval 56%-58%) and 64% (95% confidence interval 63%-65%). Diagnostic accuracy varied among population groups, with experienced dentists showing the lowest sensitivity (52%) and the highest specificity (71%). Red lesions, flat lesions, and large lesions had the lowest sensitivity (42%, 36%, 57%) but the highest specificity (70%, 75%, 76%). CONCLUSIONS: We found worrying low ability to detect suspected malignant oral lesions by both healthcare workers and non-healthcare subjects. Lesion-specific characteristics may lead to differences in recognition. Specific courses and more adequate teaching methods should be proposed to increase identification of oral lesions.

Retrospective clinical study of 1472-unit monolithic zirconia restorations with feather-edge margins realized with digital workflow.

OBJECTIVES: To evaluate the clinical performance of monolithic zirconia restorations with feather-edge margins fabricated by digital impressions. MATERIALS AND METHODS: All participants that present monolithic zirconia restorations with feather-edge margins realized with digital workflow were evaluated during scheduled periodontal maintenance between February and September 2022 according to predetermined inclusion criteria. Clinical performance was assessed using the modified USPHS and periodontal parameters. Overall survival was calculated for monolithic zirconia restorations. Technical and biologic complications were reported. Descriptive statistical analysis and life-table analyses were performed for all data. RESULTS: A total of 1472 monolithic zirconia FDPs (1279 on abutments and 193 on pontics) placed in 1189 patients (982 males and 490 females) from February 2017 to September 2020 were analyzed. The mean follow-up was 44 months (range 36-61 months), and the overall survival rate was 98.5%. There were 931 single crowns, 96 were 3-unit FDPs, 33 were 4-unit FDPs, 11 were 5-unit FDPs, and 6-unit FDPs. Three single crowns had irreparable cracks, and 6 single crowns and one 4-unit FDP were fractured. One 3-unit FDP failed due to tooth fracture and 5 single crowns failed due to endodontic failure. The loss of retention was noted in 25 monolithic zirconia FDPs and hypersensitivity in 44 single crowns. Biologic complications were uncommon. CONCLUSIONS: Based on the results and its limitations, the monolithic zirconia FPDs and digital impressions represent a favorable prosthetic treatment similar to that reported with other margin designs CLINICAL RELEVANCE: Monolithic zirconia restorations on vertical-margin abutments fabricated using a digital workflow demonstrate excellent clinical performance. The digital clinical workflow without the use of a cast means a reduction in costs, steps, and operating time.

Clinical performance of posterior monolithic zirconia implant-supported fixed dental prostheses with angulated screw channels: A 3-year prospective cohort study.

STATEMENT OF PROBLEM: The choice of retention type of an implant-supported fixed dental prosthesis (FDP) becomes critical when the dental implant is not placed in a prosthetically ideal location. In recent years, computer-aided design and computer-aided manufacturing (CAD-CAM) technology has enabled the correction of the location of screw access hole depending on the clinical needs of the patient. However, how FPDs with angulated screw channels (ASCs) perform clinically is unclear. PURPOSE: The purpose of this prospective clinical study was to evaluate the mechanical complications and crestal bone loss (CBL) when posterior monolithic zirconia implant-supported FDPs with an ASC are used. MATERIAL AND METHODS: Participants (N=37) with a missing single posterior tooth or multiple teeth, sufficient bone height, and an implant site without infection were included. Each participant received parallel-walled implants (Nobel Parallel CC) of 7-, 8.5-, or 10-mm length by using a 1-stage approach. After 4 months of healing, a conventional impression was made, and a digital workflow was followed. Monolithic zirconia restorations (Katana ML) were milled, stained, and mechanically attached to a titanium base (NobelProcera ASC abutment). CBL was measured from radiographs at 6, 12, 24, and 36 months after the placement of the prosthesis. Implant and prosthetic characteristics including implant diameter, implant length, screw channel angle (angle≤15 degrees versus angle>16 degrees), prosthetic type (single crown versus multiple-unit FDP), and antagonist dentition (natural versus prosthesis) were also recorded. A generalized linear mixed model with a log link was estimated to assess the independent predictors of CBL among the angles of ASC-retained definitive restorations and the clinically relevant variables (α=.05). RESULTS: Thirty-seven participants received 51 implants, and the median follow-up period was 30 months (interquartile range: 22-36). Two single-crown implants failed within the first 12 months of delivery. The implant and restoration survival rate was 96% at 36 months. Screw loosening was recorded in 2 study participants. After a follow-up of 36 months, the mean ±standard deviation CBL value was 0.15 ±0.14 mm with an increase over time (P<.001). The effect of the angle of ASC, implant diameter, implant length, prosthetic type, and antagonist on the CBL was not statistically significant (P>.05). CONCLUSIONS: CBL was not associated with the angle of ASC, implant diameter, implant length, prosthetic type, or antagonist when posterior monolithic zirconia implant-supported FDPs with ASCs were used. Screw loosening in 2 situations was the only mechanical complication during the first 3 years of service.

Evaluating high power laser therapy (HPLT) as treatment for chemotherapy-induced oral mucositis in paediatric patients with oncohematological diseases.

BACKGROUND: Oral mucositis (OM) is one of the most debilitating side effects of chemotherapy. Among the current methods used in OM management, the feasibility of high power laser therapy (HPLT) has been proposed but not fully evaluated. AIM: The aim of this study was to evaluate the efficacy of HPLT in the treatment of OM in paediatric patients. DESIGN: Fourteen oncohematological paediatric patients treated with chemotherapy and/or hematopoietic stem cell transplantation and affected by OM at different grades were enrolled in this study. All patients were treated with a class IV laser device in four sessions for four consecutive days, OM was evaluated with the WHO-OTS scale. The perception of pain was assessed by the visual analog scale. Photographs of and information about lesions and patient questionnaires were taken and collected, respectively. Descriptive analyses and the Wilcoxon signed-rank test (nonparametric test) were used, with a statistical significance of α = .05. RESULTS: After a week into the treatment, 57% of patients were completely healed, whereas the whole cohort experienced a drastic decrease in pain, from an average value of 5.8-1.1 (p = .0016). The average number of injuries per patient decreased from 7.4 to 3.1 (p = .008). CONCLUSION: High power laser therapy appears to be a safe and efficacious method for managing OM. It reduces pain and severity of oral cavity injuries. Further studies are needed to determine the optimal parameters useful in OM treatment and to evaluate the relative effectiveness of HPLT to other treatments like LLLT.

Computer-guided implant surgery for immediate implanting and loading: The STIL technique.

A method is described for minimizing errors in positioning a surgical template during the insertion of implants immediately after extraction and the placement of interim prostheses with immediate loading. The technique, called sequential template immediate loading (STIL), uses modular templates to fix pins before extracting the teeth, thus giving a reliable position for the subsequent templates for inserting the implant and placing the interim prosthesis.

Automatic Digital Design of the Occlusal Anatomy of Monolithic Zirconia Crowns Compared to Dental Technicians' Digital Waxing: A Controlled Clinical Trial.

PURPOSE: Reconstructing the occlusal morphology of posterior teeth in definitive dental prosthesis can be challenging. The use of the correlation technique enables replication of the information and occlusal anatomy of interim dental prostheses to the definitive ones. The purpose of this controlled clinical trial was to compare the static and dynamic contacts (SDC) of monolithic zirconia crowns designed with correlation and library techniques. MATERIAL AND METHODS: Twenty-four patients were included in the study for a total of 28 molars. For each abutment tooth, an interim crown was fabricated and two digital scans, with and without the interim crown in place were made. Two single crowns were designed using correlation and library techniques. Fifty-six monolithic zirconia crowns were milled. The interim and definitive crowns were evaluated intraorally for SDC by using a 24-µm-thick blue articulating foil. After removing the interim and definite crowns, extraoral photographs were taken to calculate the SDC area using software (ImageJ) and analyzed by the Kruskal-Wallis test. RESULTS: The average and ± standard deviation (SD) of area of the occlusal marks on interim crowns was 32.27 ± 3.45 mm2 . Definitive crowns designed by using the correlation technique had an area of 31.01 ± 3.73 mm2 ; the area in the library technique was 36.85 ± 5.78 mm2 . No statistically significant difference was found (p = 0.091) between the occlusal mark areas of the interim and definitive crowns designed by using the correlation technique. Whereas, there were significant differences between the areas of occlusal marks of the interim and definitive crowns designed by using the library technique, and between the areas of occlusal marks of definitive crowns designed by using the correlation and library techniques (p < 0.001). CONCLUSION: The average area of the SDC of monolithic zirconia crowns designed by using the correlation technique was similar to that of interim crowns. The library technique was less effective when replicating the SDC compared to the correlation technique.

Relationship between Breastfeeding Difficulties, Ankyloglossia, and Frenotomy: A Literature Review.

OBJECTIVE: Breastfeeding plays a key role in the development of the baby, in addition to the benefits to the mother and this dyad. Among the possible difficulties in this process, we have ankyloglossia. Some professionals opt for the frenotomy, although the literature is controversial. This paper aims to present how the literature provides subsidies for health professionals' decision and action in the intersection of the themes: breastfeeding, ankyloglossia, and frenotomy. MATERIALS AND METHODS: The research on the platforms SciELO and PubMed used the terms: "ankyloglossia," "frenotomy," and "lingual frenulum" and the same ones associated with "breastfeeding." A specific inclusion and exclusion criteria were applied and validated by the American Speech-Language-Hearing Association to reduce any bias in the analysis. In the end, 16 papers were included and, by thematic equivalence, divided into two domains: association between lingual frenulum alteration and breastfeeding and between frenotomy and breastfeeding. RESULTS: The literature does not assure that the frenotomy is the "standard conduct" to be adopted in cases of difficulty in breastfeeding and ankyloglossia. CONCLUSION: Further studies are needed on the different types of ankyloglossia and their direct influence on the sucking function and lactation difficulties.

Incorporating a facial scanner into the digital workflow: A dental technique.

The transfer of extraoral and intraoral clinical information into the virtual environment is necessary to optimize prosthetic treatment planning. The purpose of this article was to describe a digital workflow designed to superimpose the different 3D files obtained with an intraoral scanner, a cone bean computed tomography (CBCT) device, and a facial scanner and their clinical application with the Digital bite device.

Influence of ceramic firing on marginal gap accuracy and metal-ceramic bond strength of 3D-printed Co-Cr frameworks.

STATEMENT OF PROBLEM: The marginal gap and ceramic bond strength of metal-ceramic restorations are important for success. However, studies evaluating the marginal gap and ceramic bond strength of fixed partial dentures (FPDs) produced with 3D printing technologies such as selective laser melting (SLM) are scarce. PURPOSE: The purpose of this in vitro study was to investigate the marginal gap of cobalt-chromium (Co-Cr) alloy frameworks produced by SLM technology before and after ceramic firing. Additionally, the metal-ceramic bond strength was evaluated with the Schwickerath crack-initiation test according to the International Standards Organization (ISO) 9693-1:2012. MATERIAL AND METHODS: Conventional impressions were made, and the definitive cast of a patient requiring a 4-unit FPD was scanned. After designing the FPD, the files were sent to a service center for the fabrication of a metal master model, 80 Co-Cr frameworks, and 80 flat specimens (25×3×0.5 mm) with SLM technology. The marginal gap between frameworks and the abutment tooth of the metal master model was nondestructively measured by using an optical coordinate-measuring machine. A total of 80 sets, consisting of 1 framework and 1 flat specimen, were sent to 80 dental laboratory technicians for ceramic firing. Detailed instructions for correct manipulation of the framework and flat specimen were provided. The marginal gap was remeasured, and the 3-point bend test was used to evaluate metal-ceramic bond strength. RESULTS: Only 28 of the 80 dental technicians returned the specimens within a prespecified time and/or in adequate condition. The mean ±standard deviation marginal gap of the framework before ceramic firing was 25 ±9 µm and 34 ±12 µm after firing. The difference was statistically significant (P=.001). The mean ±standard deviation 3-point bend strength was 33 ±9 MPa. CONCLUSIONS: Ceramic firing affected the marginal gap; however, all Co-Cr frameworks had a marginal gap lower than 120 µm, which is reported to be a clinically acceptable limit. Most of the specimens (80%) had a metal-ceramic bond strength value higher than the 25-MPa ISO 9693 requirement. Five of 28 dental laboratory technicians were not able to comply with ceramic firing instructions.

Combined Orthodontic and Surgical Treatment in a 8-Years-Old Patient Affected By Severe Obstructive Sleep Apnea: A Case-Report.

An eight-years-old girl showed a restless sleep with snoring and severe apnea episodes, a mandibular retrognathia, mouth breathing, maxillary transverse discrepancy, mandibular transverse discrepancy, moderate crowding and anterior open-bite. The CBCT showed an anterior collapse of the epiglottis. The treatment consisted in a rapid palatal expansion, an epiglottoplasty and a reduction of the tongue base. Polysomnography revealed that apnea-hypopnea index improved from 21,8 episodes/hr at the baseline to 0,6 episodes/hr, average oxygen saturation from 96,5% to 98,1%, oxygen desaturation events from 23,4 episodes/hr to 1/hr.

Maturation of the Middle Phalanx of the Third Finger: A Comparative Study between Right and Left Hand.

OBJECTIVES: Recently a classification of patient's skeletal age based on the phalanx maturation, The Middle Phalanx Maturation of the third finger (MPM) method, was suggested. The aim of this study is to evaluate if there is a difference in MPM between the right and left hand. STUDY DESIGN: Two hundred fifty-four patients were obtained from the Complex Operating Unit of Orthodontics of Padua University Hospital. The total sample size has been selected by appropriate statistical calculations resulting in 130 patients. It was decided to further double the sample size of a previous study to ensure a robust statistical analysis. Radiographs of the right and left were obtained using the MPM method. Stages were compared using the right hand as a reference. The statistical analysis (Fisher exact test) was performed for the entire sample and related to gender in order to compare the right and the left hand stages. RESULTS: In MPS2, 6 out 49 (12.2%) males and 7 out 27 females (25.9%) showed MPS3 in the left hand (p-value < 0.05). In all other stages, a total agreement (100%) was found. CONCLUSION: The authors confirm the use of the right hand as reference. In patients with MPS2 an additional radiograph on the left hand can be taken in order to increase the diagnostic accuracy. In all other stages other radiographs are not needed as a total agreement between the right and left hand was found.

Influence of abutment material on peri-implant soft tissues in anterior areas with thin gingival biotype: a multicentric prospective study.

PURPOSE: The aim of the present clinical trial was to analyze, through spectrophotometric digital technology, the influence of the abutment material on the color of the peri-implant soft tissue in patients with thin gingival biotype. MATERIAL AND METHODS: Thirty-seven patients received an endosseous dental implant in the anterior maxilla. At time of each definitive prosthesis delivery, an all-ceramic crown has been tried on gold, titanium and zirconia abutment. Peri-implant soft-tissue color has been measured through a spectrophotometer after the insertion of each single abutment. Also facial peri-implant soft-tissue thickness was measured at the level of the implant neck through a caliper. A specific software has been utilized to identify a standardized tissue area and to collect the data before the statistical analysis in Lab* color space. ΔE parameters of the selected abutments were tested for correlation with mucosal thickness. Pearson correlation test was used. RESULTS: Only 15 patients met the study inclusion criteria on peri-implant soft-tissue thickness. Peri-implant soft-tissue color was different from that around natural teeth, no matter which type of restorative material was selected. Measurements regarding all the abutments were above the critical threshold of ΔE 8.74 for intraoral color distinction by the naked eye. The ΔE mean values of gold and zirconium abutments were similar (11.43 and 11.37, respectively) and significantly lower (P = 0.03 and P = 0.04, respectively) than the titanium abutment (13.55). In patients with a facial soft-tissue thickness ≤2 mm, the ΔE mean value of gold and zirconia abutments was significantly lower than that of titanium abutments (P = 0.03 and P = 0.04, respectively) and much more close to the reference threshold of 8.74. CONCLUSIONS: For peri-implant soft tissue of ≤2 mm, gold or zirconia abutments could be selected in anterior areas treatment. Moreover, the thickness of the peri-implant soft tissue seemed to be a crucial factor in the abutment impact on the color of soft tissues with a thickness of ≤2 mm.

Influence of Root Canal Posts on the Reattachment of Fragments to Endodontically Treated Fractured Incisors: An in vitro Experimental Comparison.

OBJECTIVE: The aim of this study was to establish the benefits of inserting a fiberglass post when bonding tooth fragments after complicated coronal fractures. METHODS: Thirty bovine incisors were randomly assigned to three groups: a control group of intact teeth (A), and two experimental groups (B and C). Coronal fragments were cut from the teeth in groups B and C, which then underwent root canal treatment, inserting posts in the teeth in group C. The coronal fragments were bonded to the teeth in both experimental groups using the same materials and technique, then the specimens were submitted to mechanical loading until fracture. RESULTS: The specimens in the experimental groups had a lower resistance to mechanical loading than the intact teeth. The mean failure load was: 352.77 (SD ± 62.22) N in group A, 151.04 (SD ± 45.76) N in group B, and 168.61 (SD ± 33.59) N in group C. The difference between group A and the other two groups was statistically significant (analysis of variance test: p < 0.0001), whereas there was no statistically significant difference in the force needed to fracture the teeth in groups B and C (Tukey's test: p = 0.34). When the failure mode under loading was examined, the fractures in group C never involved new tooth substance beneath the adhesion interface, whereas in group B, this was only true in one in two cases. CONCLUSIONS: Inserting a post does not significantly improve the strength of restored teeth, but it may result in a more favorable fracture mode. CLINICAL SIGNIFICANCE: Within the limitations of this in vitro study, reattaching the fragment of a fractured tooth does not seem to restore the tooth to its original load resistance. The findings of this study indicate that inserting a fiberglass post for reinforcement purposes in fractured teeth undergoing root canal treatment is unable to significantly improve their load-bearing capacity by comparison with teeth repaired without inserting a post. However, the results of the present study suggest that inserting a post may result in a more favorable fracture mode in the event of further trauma.

An In Vivo Evaluation of the Fit of Zirconium-Oxide Based, Ceramic Single Crowns with Vertical and Horizontal Finish Line Preparations.

PURPOSE: Different types of tooth preparations influence the marginal precision of zirconium-oxide based ceramic single crowns. In this in vivo study, the marginal fits of zirconium-oxide based ceramic single crowns with vertical and horizontal finish lines were compared. MATERIALS AND METHODS: Forty-six teeth were chosen in eight patients indicated for extraction for implant placement. CAD/CAM technology was used for the production of 46 zirconium-oxide-based ceramic single crowns: 23 teeth were prepared with vertical finishing lines, 23 with horizontal finishing lines. One operator accomplished all clinical procedures. The zirconia crowns were cemented with glass ionomer cement. The teeth were extracted 1 month later. Marginal gaps along vertical planes were measured for each crown, using a total of four landmarks for each tooth by means of a microscope at 50× magnification. On conclusion of microscopic assessment, ESEM evaluation was completed on all specimens. The comparison of the gap between the two types of preparation was performed with a nonparametric test (two-sample Wilcoxon rank-sum test) with a level of significance fixed at p < 0.05. All data were analyzed with STATA12. RESULTS: In the group with horizontal finish line preparations, the median value of the gap was 35.45 µm (Iqr, 0.33); for the vertical finish line group, the median value of the gap was 35.44 µm (Iqr, 0.40). The difference between the two groups was not statistically significant (two-sample Wilcoxon rank-sum test, p = 0.0872). CONCLUSIONS: Within the limitations of this study, the gaps of the zirconium-oxide-based ceramic CAD/CAM crowns with vertical and horizontal finish line preparations were not different.

Correlation between subjective and objective evaluation of peri-implant soft tissue color.

PURPOSE: While extensive references are present in the literature dealing with the correlation between subjective and objective evaluation of tooth shade, there is a lack of information on this correlation regarding the soft tissue color. The purpose of this experimental study was to verify whether a correlation between the objective and subjective evaluation exists in analyzing soft tissue color. MATERIAL AND METHODS: A total of 39 patients with at least one implant-supported restoration in the anterior maxilla were included in the study. The shade of the peri-implant mucosa was compared with the shade of the gingiva at the adjacent tooth in a subjective and in an objective manner. The subjective evaluation was performed by five dental professionals (prosthodontist, periodontist, general dentist, dental hygienist, and dental assistant) in a subjective scale (ranging from 1 to 4). The objective evaluation was obtained by means of a spectrophotometer in a CIELAB* Color Scale, and the differences were evaluated through formula ΔE=[(ΔL)²+(Δa)²+(Δb)²]¹/². To correlate the subjective and the objective evaluation, for each arithmetical median value of the subjective evaluation, a mean value of objective evaluation has been calculated, and the Spearman's rank correlation coefficient has been used. The differences have been also analyzed for thin and thick tissue biotypes. RESULTS: The mean ∆E value for the subjective evaluation between peri-implant soft tissue and adjacent tooth gingival tissue was ∆E = 9.74. Also, mean ∆E values of 10.35 and 7.54 have been reported for thin and thick biotypes, respectively. Mean values of ∆E = 6.63, 8.54, and 15.54 were presented by median values of 1 (perfect matching), 2 (good matching), and 3 (clinically distinguishable), respectively. The threshold for the distinction of differences of mucosal color by the human eyes between perfect or good matching and distinguishable values has been calculated in ∆E = 8.74. CONCLUSIONS: Within the limitation of this study, a correlation between the subjective and the objective evaluation of the peri-implant soft tissue exists and the threshold for the distinction of mucosal color differences between perfect or good matching and distinguishable subjective values has been calculated in ∆E = 8.74 in the objective evaluation.

Comparison of magnetic resonance imaging findings in temporomandibular joints of the two sides.

OBJECTIVES: The aim of this investigation was to assess the association of magnetic resonance imaging (MRI)-diagnosed temporomandibular joint (TMJ) disorders [i.e., disc displacement with reduction, disc displacement without reduction (DDNR), osseous changes (OC), joint effusion] on the same side as well as in the joints of the two sides of the same individual. MATERIALS AND METHODS: A total of 199 patients undergoing bilateral MRI of the TMJs were included in the study. A single variable correlation matrix was created to assess the within- and between-side correlation of single diagnoses. Then, based on 12 possible combinations of diagnoses per each side, a contingency table was created to assess the chi-square values of the differences between the observed and expected frequencies of the different cross-combinations. Multiple variable permutation test was performed to assess the null hypothesis that the diagnoses in the right and left joints are not related. RESULTS: Within the signs of the same side, DDNR was positively correlated with OC. As for combination of diagnoses, the presence of a specific combination of signs on one side implied the same combination of signs on the other side. The global multivariate permutation test with Tippett combination was significant at p < 0.001, showing that the null hypothesis of independence between diagnoses of the two sides was rejected. CONCLUSIONS: It can be suggested that disc displacement without reduction is associated with osseous changes of the same joint and that joints of the two sides are likely to be affected by the same combinations of MRI signs. CLINICAL RELEVANCE: This investigation supports the concept that the two temporomandibular joints work as a unit.

Canalicular adenoma immunoprofile: a case report.

OBJECTIVES: To report a case of canalicular adenoma (CA) and discuss the use of immunohistochemistry to better address the diagnosis given some unusual characteristics in this patient. BACKGROUND: CA is an uncommon benign neoplasm that can develop in minor salivary gland duct tissues throughout the oral cavity. At histology, it shares several features with other salivary tumors. Immunohistochemistry can be useful in the differential diagnosis. MATERIALS AND METHODS: The clinical presentation consisted in a nodule on the left upper lip of an 85-year-old man. The patient's main complaint was upper denture instability secondary to soft tissue changes. The nodule was excised under local anesthesia and underwent histological and immunohistochemical examination to rule out any malignancy. RESULTS: Histological findings, cytokeratin positivity and the absence of any reactivity to specific markers of myoepithelial differentiation confirmed the epithelial nature of the lesion. CONCLUSION: The histological diagnosis of benign salivary tumors such as CA can be confirmed by immunohistochemistry.