Impact of Auxiliary Features on Retention of Short Dental Crowns: An In-Vitro Analysis of Box and Groove Preparations.

BACKGROUND Several auxiliary features have been proposed to achieve sustainable retention for short-prepared dental crowns; however, achieving retention is challenging. This study aimed to assess the impact of increased total occlusal convergence and auxiliary preparation factors like box and groove on the retention form of short tooth preparations. MATERIAL AND METHODS Eighty resin machine-milled dies with a height of 3 mm and a deep chamfer margin of 1 mm were prepared to mimic the short-prepared molar. Initially, 2 teeth were prepared following the guidelines, and the total occlusal convergence was kept at 10° and 20°, respectively. Auxiliary features such as the proximal box and buccal groove were prepared on separate 20° dies. Eighty dies were prepared with 10 samples each for 10°, 20°, 20° with proximal box and 20° with buccal groove for zirconia (n=40) and metal crowns (n=40). Cementation was done with glass ionomer luting cement, and a pull-off test was conducted. Data were analyzed using one-way analysis of variance and post hoc fisher least significant difference test (P<0.05). RESULTS The highest mean was observed in the proximal box group with the metal crown (14.59), and the lowest in the group with 20° zirconia crowns (9.12). Within groups, the highest retentive values were found for the 20° taper with proximal box preparation; the lowest was for the 20° taper group. CONCLUSIONS Within the study limitations, it could be concluded that incorporating a proximal box or buccal groove in short tooth preparations with an increased total occlusal convergence improved retentive values.

Comparative Accuracy of Intraoral and Extraoral Digital Workflows for Short Span Implant Supported Fixed Partial Denture Fabrication: An In Vitro Study.

BACKGROUND The advent of digital impressions using computer-aided design and manufacturing technology (CAD/CAM) has simplified and improved the fabrication of implant prostheses in dentistry. The conventional impression has several drawbacks, including tray selection, material type, impression technique, impression disinfection, and cast model storage. The inaccuracies caused by distortion and contraction of impression material can be minimized with digital impressions. This study aimed to compare digital dental impressions of 10 working casts made using the Pindex laser removable die system to fabricate parallel drill channels vs 10 working casts made using the Di-Lok plastic tray removable die system. MATERIAL AND METHODS An implant master die with 2 dental implant analogs was fabricated. Ten working casts using the Pindex laser removable die system with parallel drill channels and 10 working casts using the Di-Lok plastic tray removable die system were fabricated. The working casts were scanned using an extra-oral laboratory scanner and the implant master model was scanned with an intra-oral scanner. RESULTS The properties of the casts made using the 2 systems were evaluated and analyzed with ANOVA and post hoc Tukey test. The mean horizontal linear distances between A1B1 (P<0.021), A2B2 (P<0.018), C1D1 (P<0.026), C2D2 (P<0.03), B1C1 (P<0.01), and mean vertical distances between B1A2 (P<0.015), C1D2 (P<0.001), B1B2 (P<0.028), and C1C2 (P<0.001) were significantly different between the Pindex system and Di-Lok tray system as compared to intra-oral scans. CONCLUSIONS Complete digital workflow with intra-oral scans were more than the partial digital workflow with extra-oral scans for the Pindex system and Di-Lok tray systems.

Shear Strength of Repaired 3D-Printed and Milled Provisional Materials Using Different Resin Materials with and without Chemical and Mechanical Surface Treatment.

The aim of this study was to assess the shear bond strength of 3D-printed and milled provisional restorations using various resin materials and surface finishes. There were 160 preliminary samples in all, and they were split into two groups: the milled group and the 3D-printed group. Based on the resin used for repair (composite or polymethylmethacrylate (PMMA)) and the type of surface treatment utilized (chemical or mechanical), each group was further divided into subgroups. The specimens were subjected to thermocycling from 5 °C to 55 °C for up to 5000 thermal cycles with a dwell time of 30 s. The mechanical qualities of the repaired material underwent testing for shear bond strength (SBS). To identify the significant differences between the groups and subgroups, a statistical analysis was carried out. Three-way ANOVA was used to analyze the effects of each independent component (the material and the bonding condition), as well as the interaction between the independent factors on shear bond strength. Tukey multiple post-hoc tests were used to compare the mean results for each material under various bonding circumstances. The shear bond strengths of the various groups and subgroups differed significantly (p < 0.05). When compared to the milled group, the 3D-printed group had a much greater mean shear bond strength. When compared to PMMA repair, the composite resin material showed a noticeably greater shear bond strength. In terms of surface treatments, the samples with mechanical and chemical surface treatments had stronger shear bonds than those that had not received any. The results of this study demonstrate the effect of the fabrication method, resin type, and surface treatment on the shear bond strength of restored provisional restorations. Particularly when made using composite material and given surface treatments, 3D-printed provisional restorations showed exceptional mechanical qualities. These results can help dentists choose the best fabrication methods, resin materials, and surface treatments through which to increase the durability and bond strength of temporary prosthesis.

Evaluation of the Effects of Digital Manufacturing, Preparation Taper, Cement Type, and Aging on the Color Stability of Anterior Provisional Crowns Using Colorimetry.

BACKGROUND Replicating the 3-dimensional (3D) color of natural teeth in artificial substitutes is challenging. Fixed dental prosthodontics require aesthetic, color-stable provisional restorations. Recent milling and 3D printing digital manufacturing techniques offer improved outcomes. This study assesses color stability in various digital manufacturing methods, tapers, and aging effects on anterior provisional resin restorations. MATERIAL AND METHODS Two all-ceramic tooth preparations on typodont teeth with 10° and 20° tapers were converted into experimental dies. Forty temporary crowns were manufactured using 3D printing and computer-aided design/computer-aided manufacturing (milling). Within these 2 groups, 10 crowns were cemented using a regular and clear provisional cement. All samples were thermocycled to simulate clinical use of 6 months. Color difference formula (CIEDE2000) indicated changes between before and after cementation (ΔE00) and between after cementation and after thermocycling (ΔE00[II]). The color change was considered significant in terms of clinically perceptible (ΔE00 ≤0.62) and acceptable (ΔE00 ≤2.62) changes. One-way ANOVA (P value of less than 0.05) calculated overall differences, which were established using a Fisher post hoc test. RESULTS Crowns cemented with clear cement showed fewer color changes irrespective of the manufacturing technique or taper. Notably, only the 10° 3D-printed crown with clear cement had an imperceptible color change at the pre-/post-cementation phase. Meanwhile, the 10° and 20° milled crowns with regular cement exhibited unacceptable color changes after thermocycling. CONCLUSIONS For long­term temporization in the aesthetic zone, properly optimized 3D-printed provisional restorations cemented with clear cement had better color stability.

PEEK surface treatment on surface roughness and bond integrity to composite resin utilizing Er: YAG, Rosebengal activated by PDT, and aluminum trioxide particles.

AIMS: To evaluate the impact of conditioning protocols, aluminum trioxide (Al2O3), Er:YAG laser (EYL), and Rosebengal (RB), on the surface roughness (Ra) and shear bond strength (SBS) of polyetheretherketone (PEEK) attached to composite restorations. METHOD: Eighty PEEK discs in total were produced and then divided into four groups (n = 20). Group1:Sulfuric acid (SA), Group 2: PDT (RB), Group 3: Al2O3, Group 4 EYL, respectively. The Ra of PEEK discs was evaluated using the surface profilometer. After being luted, the discs were attached to composite resin discs. After that, samples were put to SBS testing on a Universal testing apparatus. A stereo microscope was also used to evaluate the type of breakdown. The data were analyzed using Tukey's test and one-way analysis of variance. RESULTS: The SA treated group exhibited the highest Ra. Nevertheless, the RB specimens activated by PDT treatment had the lowest mean Ra score. The group that received the treatment of SA exhibited the highest average score of SBS. In contrast, specimens treated with PDT and activated by RB exhibited the lowest levels of bond fidelity. Cohesive failure emerges as the prevailing kind of fracture within the various groups subjected to testing. CONCLUSION: The utilization of Al2O3, RB activated by PDT, and EYL shows promise as a viable substitute for Sulfuric acid in enhancing the bond integrity of composite cement and surface roughness in PEEK materials.

Comparative Evaluation of Dimensional and Occlusal Accuracy of Non-Working Antagonist Casts: A Study on Different Impression Materials and 3D Printing.

BACKGROUND The aim of this study was to assess and compare the vertical/horizontal dimensions and occlusal accuracy of non-working/opposing casts obtained from three different impression materials and 3D print cast. MATERIAL AND METHODS Dentulous Master models simulating a case of a fixed dental prosthesis were mounted on an articulator (control group). Opposing mandibular casts obtained from three different impression materialsand 3-dimensional print constituted test groups , ,and , respectively. Three points, anterior vertical (AV), posterior vertical (PV), and anteroposterior (AP) were compared for dimensional accuracy among casts. Occlusal accuracy was analyzed on Medit Link software at 3 teeth (#13, #17, and #27). After calculating means for each group, the differences were calculated at probability value of P≤0.05 using the single-sample t test, ANOVA, and Tukey test. RESULTS The dimensions were significantly different from those of the mounted master models except in Gp AL(E) and Gp AL(F) at AV dimension and Gp AL(E) at AP dimension (P>0.05). A statistically significant difference of the error of means among the 4 tested groupswere detected only at 2 dimensions (AV and PV) between the Gp AL(E) and Gp 3D-C and between Gp AL(F) and Gp 3D-C groups. Other groups showed no significant differences. CONCLUSIONS The opposing casts obtained from the extended-pour alginate and alginate alternative impression materials showed higher occlusal accuracy compared to conventional alginate and 3D printed casts.

Effect of smokeless tobacco on color stability and surface roughness of CAD/CAM milled, 3D printed, and conventional provisional crown and fixed dental prosthesis materials: An in vitro study.

BACKGROUND: Provisional fixed dental prosthesis (FDP) plays an important role during fixed prosthodontic therapy till the definitive. Discoloration of materials used for provisional FDPs can cause patient dissatisfaction and may create doubt about the color stability of the definitive FDP. Surface roughness is the other major property to be taken into consideration for provisional FDP materials. Smokeless tobacco is reported to affect the color stability and surface roughness of different prosthetic materials. OBJECTIVE: The aim of the current study was to evaluate the effect of two types of smokeless tobacco (black and white) on color stability and surface roughness of 3D printed, CAD/CAM milled, and conventional provisional FDP resin materials. METHODS: A total of 144 disc-shaped specimens were fabricated using four techniques CAD/CAM subtractive technique (milling), CAD/CAM additive technique (3D Printing), and conventional technique using autopolymerized PMMA, and autopolymerized Bis-acrylic resins. Each group was subdivided into three subgroups of twelve specimens each, and were submerged into three solutions (artificial salivary substitute, black smokeless tobacco, white smokeless tobacco). The change in color and surface roughness was evaluated and the data collected were statistically analyzed. RESULTS: It was observed that black smokeless tobacco caused the maximum color change and the effect was highest in autopolymerized PMMA resin specimens (ΔE = 9.343 ± 0.489), followed by 3D printed (ΔE = 7.187 ± 0.391), autopolymerized Bis-acryl (ΔE = 6.464 ± 0.453) and milled (ΔE = 4.978 ± 0.227). White smokeless tobacco was found to cause a maximum change in surface roughness and the effect was highest in autopolymerized Bis-acryl specimens (ΔRa = 0.321 ± 0.015 µm), followed by autopolymerized PMMA (ΔRa = 0.297± 0.015 µm), 3D printed (ΔRa = 0.191 ± 0.019 µm), and milled (ΔRa = 0.168 ± 0.014 µm). Statistically significant (p-value < 0.05) differences were observed among all techniques and solutions. CONCLUSIONS: The change in color and surface roughness were maximum in the case of FDPs prepared using autopolymerizing resins, followed by 3D printed, and CAD/CAM milled reins.

Ceramic versus Composite Resin Polishing Systems on the Surface Roughness of Milled Leucite-Reinforced Ceramics.

Background and Objective: This study aimed to compare the surface finish of milled leucite-reinforced ceramics polished with ceramic and composite polishing systems based on the manufacturers' recommendations. Materials and Methods: Sixty subtractive computer-aided manufactured (s-CAM) leucite-reinforced glass-ceramic specimens (IPS-Empress-CAD) were assigned into six groups: no polishing, a ceramic polishing kit, and four composite kit groups. The roughness average (Ra) was evaluated in microns using a profilometer, and scanning electron micrographs were obtained for qualitative analysis. A Tukey HSD posthoc test (α = 0.05) was used to determine significant intergroup differences. Results: After surface evaluation of the ceramics, the Ra values of the polishing systems ranked OptraFine (0.41 ± 0.26) < Enhance (1.60 ± 0.54) < Shofu (2.14 ± 0.44) < Astropol (4.05 ± 0.72) < DiaComp (5.66 ± 0.62) < No Polishing (5.66 ± 0.74). Discussion: Composite polishing systems did not provide as smooth surfaces as the ceramic polishing kit for CAD-CAM leucite-reinforced ceramics. Thus, using ceramic polishing systems, polishing leucite ceramics is recommended, whereas composite polishing systems should not be considered as an alternative for use in minimally invasive dentistry.

Accuracy Comparison between Robot-Assisted Dental Implant Placement and Static/Dynamic Computer-Assisted Implant Surgery: A Systematic Review and Meta-Analysis of In Vitro Studies.

Background and Objectives: The present systematic review and meta-analysis undertake a comparison of studies that examine the accuracy of robot-assisted dental implant placement in relation to static computer-assisted implant surgery (SCAIS), dynamic computer-assisted implant surgery (DCAIS), and freehand procedures. This study aims to provide a comprehensive understanding of the precision of robot-assisted dental implant placement and its comparative efficacy in relation to other placement techniques. Methods: The guidelines recommended by Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) were used to organize and compose this review. Four electronic databases (PubMed, Web of Science, Scopus, and Cochrane) were systematically searched for pertinent articles. Articles were selected following the inclusion and exclusion criteria. Qualitative and quantitative analyses of the selected articles were performed. Results: The initial electronic search resulted in 1087 hits. Based on the inclusion and exclusion criteria, five articles were selected for qualitative analysis, out of which three were considered for quantitative analysis. Three parameters were considered for accuracy evaluation (angular, coronal, and apical deviation). The mean angular deviation was -1.22 degrees (95% CI, -1.06--1.39), the mean coronal deviation was -0.15 mm (95% CI, -0.24--0.07), and the mean apical deviation was -0.19 mm (95% CI, -0.27--0.10). Conclusions: The robotic implant system was found to have significantly lower angular deviations and insignificantly lower coronal and apical deviations compared to DCAIS. Within the limitations of this review, it can be concluded that robot-assisted implant placement in resin models permits higher accuracy compared to DCAIS and SCAIS systems. However, due to the limited number of comparative studies with high heterogeneity, the findings of this review should be interpreted with caution. Further research is necessary to confirm the clinical application of robotics in implant surgery.

Influence of Glycemic Control on the Survival of Implants Placed in the Zygomatic Bone of Edentulous Patients With and Without Type 2 Diabetes Mellitus: 10-Year Follow-Up Results.

It is hypothesized that under optimal glycemic control (GC), there is no difference in the survival of implants placed in the zygomatic bone of edentulous patient with and without type 2 diabetes mellitus (T2DM). The aim was to assess the influence of GC on survival of implants placed in the zygomatic bone of an edentulous patient with and without T2DM at the 10-year follow-up. Twenty patients with T2DM (10 with poorly controlled T2DM and 10 with well-controlled T2DM) and 12 patients without T2DM were included. Hemoglobin A1c (HbA1c) levels were recorded, and demographic data were collected from all participants. Peri-implant inflammatory parameters (plaque index [PI], probing depth [PD], crestal bone loss [BL], and gingival index [GI]) were measured in all patients. Group comparisons were done, and P values, which were less than .01, were indicative of statistical significance. Twenty and 12 male patients with and without T2DM, respectively, were included. Among patients with T2DM, 10 and 10 individuals had poorly and well-controlled T2DM, respectively. The mean HbA1c levels were significantly higher in patients with poorly controlled T2DM (9.2 ± 0.7%) compared with well-controlled T2DM (4.8 ± 0.3%; P < .01) and nondiabetic individuals (4.6 ± 0.3%; P < .01). The crestal BL on the mesial (P < .01) and distal (P < .01) surfaces, PD (P < .01), PI (P < .01), and GI (P < .01) were significantly higher around all zygoma implants placed in patients with poorly controlled T2DM compared with patients with well-controlled T2DM and patients without T2DM. These clinicoradiographic parameters were comparable around zygoma implants placed in patient with well-controlled T2DM and in subjects without T2DM. Optimal GC is essential for the long-term stability of zygomatic plants in patients with T2DM.

A customized metal guide for controllable modification of anterior teeth contour prior to minimally invasive preparation.

OBJECTIVE: Optimal tooth reduction is a key requirement for aesthetics, function, and the longevity of fixed restorations. Research has demonstrated that controlled and conservative tooth preparation is crucial for the long-term success of adhesive restorations. Different techniques of fabricating reduction guides have been previously reported in literature. The present technical note describes the fabrication technique and clinical application of a customized metal preparation reduction guide. MATERIAL AND METHOD: Patient presented with tilted maxillary left central incisor. The flared-out part of the tooth was modified prior to veneer restoration preparation. Resin pattern reduction guide was fabricated on the diagnostic cast with a window on the tilted mesial portion of the tooth. After intraoral evaluation, resin pattern guide was casted. Metal reduction guide was place intraorally and reduction was provided on the exposed surface of the tooth. After the removal of the tilted portion, a harmonious arch form allowed the clinician to provide adequate evaluation and preparation for veneer restorations. RESULTS: The device demonstrated good practical value, allowing for selective and controlled reduction of tooth structure, and definitive protection of adjacent tooth surfaces from iatrogenic damage. The clinical outcome successfully addressed the patient's restorative and aesthetic needs, and the veneer was stable 2 years postoperatively. CONCLUSION: Use of a metal guide assists clinicians to provide a more predictable reduction of a desired tooth surface, while decreasing the risk of compromising the other/adjacent tooth surfaces.

Esthetic outcome for implant therapy of a maxillary lateral incisor using prefabricated titanium and customized zirconia abutments: 4-year clinical reports.

The reported clinical scenarios presented two patients, one managed with a prefabricated abutment and the other with a customized abutment, and both patients were pleased with the outcome. However, from a professional viewpoint, the esthetic outcome using the custom zirconia abutment was superior to that using the prefabricated titanium abutment.

Evaluation of the implant diameter on the initial-stability of narrow- and standard-diameter implants placed in simulated Type-I and Type-IV bone-blocks.

OBJECTIVE: A comparison of the initial stability of narrow- and standard-diameter implants (SDIs) placed in Type-I and Type-IV bone-blocks is not yet reported. The aim was to evaluate in-vitro the influence of implant diameter on the initial stability of narrow- and standard-diameter implants (SDIs) placed in simulated Type-I and Type-IV bone-blocks. METHODS: The present experimental in-vitro study was performed between July and September 2020 at the Specialist Dental Practice, Riyadh, Saudi Arabia. Narrow- and standard-diameter implants were placed 3-mm apart in simulated soft (Type-IV) and dense (Type-I) bone blocks by a trained and calibrated investigator. In groups A (Type-IV bone blocks) and B (Type-I bone blocks), implants were inserted using an insertion-torque and drilling-speed of 15-30 Ncm and 1000-1500 rpm, respectively with the implant collar at the crest of simulated bone blocks. In all samples, initial-stability was recorded using resonance frequency analysis (RFA). Sample-size estimation was done and group-comparisons were carried out. A P-value of 0.01 or less reflected statistical significance. RESULTS: In Groups-A and -B, 44 (22 NDIs and 22 SDIs) and 44 (22 NDIs and 22 SDIs) were placed. In group-A, the mean RFA values for NDIs and SDIs were 68.5 ± 3.5 and 69.1 ± 2.4, respectively. In Group-B, the mean RFA values for NDIs and SDIs were 78.06 ± 9.6 and 75.3 ± 5.2. RFA values among NDIs and SDIs in groups A and B were similar. CONCLUSION: The NDIs and SDIs show comparable initial-stability when positioned in simulated Type-I and Type-IV bone blocks.

Influence of time and hydration (ageing) on flexural strength of Yttrium stabilized Zirconia polycrystals (Y-TZP) fabricated with different CAD-CAM Systems.

OBJECTIVES: To evaluate the effect of time and hydration (ageing) on flexural strength of yttrium-stabilized zirconia polycrystals (Y-TZP) zirconia fabricated from three different materials. METHODS: This in-vitro study was performed from June to September 2019. Y-TZP bars, measuring 2 x 3 x 20 mm were prepared and sintered from three different materials, Group-1: LAVA™ Zirconia (3M ESPE, US) (control) Group-2: Vita In-Ceram YZ (VITA, Germany) and Group-3: Aadva™ Zirconia (Zr) (GC Advanced technologies Inc.). 30 zirconia bars per group were prepared using sectioning of blocks with isomet saw. Followed by sintering in furnaces for recommended temperature cycles. One side of bars were polished and beveled for flexural testing. Groups of specimens were divided into subgroups of 3 (n=10) based on the ageing (distilled water in the incubator at 37ºC) durations (48 Hrs and two and half years). Ten specimens in each material groups were not aged (controls). Samples were exposed to a static force in a three-point bend test using a universal instron-testing machine until fracture. Scanning electron microscopic assessment was performed for fractured specimens for ageing. Data was analyzed using ANOVA and Tukey post hoc test. RESULTS: The mean flexural strength at baseline for Group-1: LAVA™ Zirconia, group (632.7 ± 136.5 MPa) 2: Vita In-Ceram YZ (1036.3 ± 229.6 MPa), and Group-3: Aadva™ Zirconia (1171.3 ± 266.3 MPa) were significantly different. Group-2 and Group-3 specimens showed higher strength compared to Group-1 specimens, irrespective of the ageing duration (p<0.05). Analysis of pooled data for flexural strength for materials by aging period (baseline, after 48 hours and after 2 and ½ years) showed that there was significant reduction of strength with increasing duration (p<0.05). CONCLUSIONS: Y-TZP showed variations in flexural strength depending on the material type. Ageing duration exhibited significant influence on the flexural strength of Y-TZP when comparing no ageing to two and half years. Vita In-Ceram YZ and Aadva Zirconia (Zr) showed higher and clinically acceptable flexural strength outcomes.

Assessment of self-rated pain perception and whole salivary cortisol levels among adolescents with and without temporomandibular disorders.

Objective: To assess the self-perceived pain perception (PP) and whole salivary cortisol levels (CL) among adolescents with and without temporomandibular disorders (TMD).Methods: Adolescents between 15 and 17 years were included. Participants were categorized into three groups: Group 1: patients with TMD; Group 2: nocturnalbruxers without TMD; and Group 3: controls. Demographic data CL and self-rated PP were assessed. A p-value < 0.05 was proposed as statistically significant.Results: Fifty-four patients (18 per group) were included. Scores of self-rated PP in the affected TMJ were higher in Group 1 than Group 2 (p < 0.001). Whole salivary CL were higher in groups 1 and 2 (p < 0.01) than in Group 3. Whole salivary CL were higher in Group 2 than Group 3 (p < 0.05).Conclusion: Whole salivary CL are higher in adolescents with TMD, and there is a direct relationship between self-rated PP in the TMJ area and salivary CL.

Cortisol levels in the peri-implant sulcular fluid among patients with and without peri-implantitis.

BACKGROUND AND OBJECTIVE: Cortisol levels remain uninvestigated in peri-implant sulcular fluid (PISF) of patients with and without peri-implantitis. The present investigation investigated levels of cortisol in PISF among controls (individuals without peri-implantitis) and patients with peri-implantitis. METHODS: The patient population comprised of participants with and without peri-implantitis (groups 1 and 2, respectively). Demographic information and data related to implant characteristics was recorded. Peri-implant radiographic (crestal bone loss [CBL]) and clinical (modified plaque and bleeding on probing indices [PI and BOP], and probing depth [PD]) and parameters were assessed. In all patients, levels of cortisol were measured in the PISF, which was collected using standard methods. Data normality and group comparisons were assessed, and multiple logistic regression was performed. Probability values less than 0.01 were nominated as being significant. RESULTS: Eighty-eight individuals (44 and 44 in groups 1 and 2, correspondingly) were included. In group 1, 24 and 20 participants were males and females, and there were 22 and 22 males and females in group 2. Mean ages were analogous in both groups. Peri-implant BOP (p < .001); CBL (p < .001); PI (p < .001); and PD (p < .001) were higher among patients in group 1 compared with group 2. The volume of PISF (p < .001) collected and its concentrations of cortisol (p < .001) were significantly higher among patients in group 1 compared with group 2. Regression analysis showed that CBL and PD directly correlated with increased PISF levels of cortisol among participants with peri-implantitis. CONCLUSION: Within the limits of the present study, it remains debatable whether or not PISF cortisol levels vary among patients with and without peri-implantitis. Further studies are needed to evaluate the role of PISF levels of cortisol in the diagnosis of peri-implantitis.

Light Transmission for a Novel Chairside CAD/CAM Lithium Disilicate Ceramic.

AIM: To evaluate light transmission in a novel chairside CAD/CAM lithium disilicate ceramic with different thicknesses and with and without polishing. MATERIALS AND METHODS: Sixty flat samples (10 specimens/group) were fabricated from novel chairside CAD/CAM lithium disilicate ceramic blocks (Amber Mill, Hass Bio) with different thicknesses and with and without polishing as follows: (1) 1.0 mm thickness without polishing (1.0NoP); (2) 1.0 mm thickness with polishing (1.0Po); (3) 1.5 mm thickness without polishing (1.5NoP); (4) 1.5 mm thickness with polishing (1.5Po); (5) 2.0 mm thickness without polishing (2.0NoP); and (6) 2.0 mm thickness with polishing (2.0Po). Specimens were polished with a polishing system for lithium disilicate restorations following the manufacturer's recommendations. Light transmission was evaluated with a curing radiometer. Obtained data were subjected to two-way ANOVA followed by Tukey's post hoc tests (α = 0.05). SEM observations were conducted to evaluate surface microstructure. RESULTS: The light intensity through the lithium disilicate blocks with and without polishing was 200.9 mW/cm2 (16.1%) and 194.4 mW/cm2 (15.6%) for 1.0 mm specimens, 119.3 mW/cm2 (9.5%) and 111.9 mW/cm2 (9.0%) for 1.5 mm specimens, and 102.3 mW/cm2 (8.2%) and 96.0 mW/cm2 (7.7%) for 2.0 mm specimens. SEM images showed a smoother surface with polishing compared to nonpolished specimens. CONCLUSION: The thickness and polishing of the restorations were both significant influential factors in light transmission. CLINICAL SIGNIFICANCE: The range of light transmission percentage through the novel chairside CAD/CAM lithium disilicate blocks was 7.7-16.1%, suggesting that light attenuation through the material may influence the polymerization reaction of resin luting cement in the bonding process.

Comparison of peri-implant soft tissue and crestal bone status of dental implants placed in prediabetic, type 2 diabetic, and non-diabetic individuals: a retrospective cohort study.

BACKGROUND: Clinicoradiographic status of narrow-diameter implants (NDIs) among patients with prediabetes and type 2 diabetes mellitus (DM) is scarce. The aim was to address the clinicoradiographic status of NDIs placed prediabetic, type 2 diabetic, and non-diabetic individuals. In this retrospective cohort study, patients having undergone oral rehabilitation with NDI were included. The participants were divided into the following: (a) patients with prediabetes; (b) patients with poorly controlled type 2 DM; (c) patients with well-controlled type 2 DM; and (d) normoglycemic individuals. Demographic data was collected. In all groups, peri-implant plaque index (PI), gingival index (GI), probing depth (PD), and mesiodistal CBL were measured in all groups. Information related to implant dimensions, surface characteristics, insertion torque, implant geometry, duration of NDI in function, and jaw location of NDI was also recorded. Data normality was assessed and group comparisons were performed. A probability value under 0.01 was considered statistically significant. RESULTS: Eighty-three patients (20 patients had prediabetes, 22 with poorly controlled type 2 DM, 20 with well-controlled type 2 DM, and 20 self-reported non-diabetic individuals) were included. The mean HbA1c levels were significantly higher among patients with prediabetes (P < 0.01) and poorly controlled type 2 DM (P < 0.01) than patients with well-controlled type 2 DM and non-diabetic controls. Peri-implant PI, GI, PD, and mesiodistal CBL levels were significantly higher among patients with pre-diabetes (P < 0.01) and poorly controlled type 2 DM (P < 0.01) than patients with well-controlled type 2 DM and non-diabetic controls. Peri-implant PI, GI, PD, and mesiodistal CBL levels were significantly higher among patients with poorly controlled type 2 DM (P < 0.01) than patients with prediabetes. CONCLUSION: Chronic hyperglycemia increases the risk of peri-implant diseases around NDIs.

Clinical peri-implant health and biological bone marker levels in tobacco users treated with photodynamic therapy.

BACKGROUND: What impact does tobacco smoking have on photodynamic therapy (PDT) outcome is still unknown. The aim of the present clinical trial was to evaluate the clinical, radiographic, and biological bone markers after provision of PDT in cigarette, e-cigarette, and never-smokers with peri-implantitis (PI) at 6 months post treatment. MATERIALS AND METHODS: Twenty-five healthy patients with PI were divided into three groups: Group I: cigarette smokers; Group II: e-cigarettes users; Group III: never-smokers. Full-mouth mechanical debridement with adjunctive methylene blue-mediated PDT was performed. Clinical recordings included peri-implant plaque index (Pi), bleeding on probing (BOP) and probing depth (PD). Peri-implant sulcular fluid was collected for the assessment of biological bone biomarkers including receptor activator of nuclear factor-ligand (RANK-L) and osteoprotegrin (OPG). All assessments were performed at baseline, 3 months and 6 months. P-value of <0.05 was considered significant. RESULTS: BOP in Group II and III significantly reduced at 3 months (p < 0.05). Group I showed significant reduction only at 6 months (p < 0.05). Mean PD showed no statistically significant difference between the groups at any time-point. Inter-group comparison showed Group III demonstrating statistically significantly reduced mean RANK-L levels at both 3 and 6 months (p < 0.05). A slight increase in the OPG levels were observed at 3 months and followed by a slight decrease at 6 months for all the study groups when compared with baseline values, however, these values did not show statistical significance (p > 0.05). CONCLUSION: Adjunctive PDT helped in reducing the clinical peri-implant inflammation. However, no significant change was observed for biological bone biomarkers among tobacco smokers.

Clinical and immunological peri-implant parameters among cigarette and electronic smoking patients treated with photochemotherapy: A randomized controlled clinical trial.

BACKGROUND: Although studies have been done that evaluated the effect of photodynamic therapy (PDT) in cigarette smokers and vapers, however, literature on the impact of these types of smoking on peri-implant parameters lack. The present clinical trial assessed the effectiveness of PDT as an adjunctive therapeutic modality in the treatment of peri-implant mucositis (p-iM) in individuals vaping e-cigs and cigarette smokers. METHODS: Individuals with p-iM were divided into three groups. (a) Group 1: Cigarette smokers with p-iM (b) Group 2: Vapers (e-cigarette smokers) with p-iM, (c) Group 3: Non-smokers with p-iM. Plaque index (PI), bleeding on probing (BOP) and probing depth (PD) were calculated. Pro-inflammatory biomarkers including matrix metalloproteinase (MMP)-8 and tumor necrosis factor-alpha (TNF-α) were quantified using enzyme linked immunosorbent assay. All assessments were performed at baseline (before treatment) and 12 weeks post treatment. Full mouth disinfection (FMD) was done with the ultrasonic scaler and copious irrigation. The photodynamic therapy (PDT) was done with a diode laser (wavelength: 670 nm, power: 150 mW, density: 1.1 W/cm2). Methylene blue photosensitizer (0.005% concentration) was incorporated inside the periimplant pockets (10 seconds at a depth of 3 mm), and the pockets were irradiated a flexible tip for one minute on the buccal and lingual surfaces. The session of PDT was performed only once at baseline. RESULTS: Twenty-five cigarette-smokers (Group 1), 21 electronic cigarette smokers (Group 2) and 25 never-smokers (Group 3) participated in the study. The mean age of the selected participants in groups 1, 2 and 3 was 29.5, 27.8, and 30.2 years, respectively. Statistically significant reduction in PI and PD parameters was observed on baseline and at 12 weeks in all groups. BOP significantly increased in group 1 and 2 at 12 weeks. A statistically significant reduction from baseline to 12 weeks was reported in the biomarker levels for all the study groups. CONCLUSION: PDT with adjunctive mechanical debridement reduced the plaque index and probing depth, while increased bleeding on probing, in addition to reducing pro-inflammatory biomarkers in tobacco smokers.