Clinical, radiographic and restorative parameters for short tuberosity implants placed in smokers: a retrospective study with 5 year follow-up.

This study aimed to estimate and compare the clinical, radiographic, and restorative parameters around short tuberosity implants (STIs) placed in cigarette smokers (CS) and never smokers (NS). In this 60-month follow-up retrospective study, a total of 50 (37 males + 13 females) individuals who had received 82 dental implants were included. These participants were categorized into two groups as follows: (i) Group-1: 25 self-reported systemically healthy CS with 43 STIs; and (ii) Group-2: 25 self-reported systemically healthy NS with 39 STIs. In both groups, peri-implant plaque index (PI), probing depth (PD), bleeding on probing (BOP), and crestal bone loss (CBL) and restorative parameters were measured at 12 and 60 months of follow-up. Group comparisons were performed utilizing the Kruskal-Wallis test. The significance level was set at p < 0.05. In CS and NS, the mean age of participants was 58.5 and 60.7 years, respectively. No statistically significant differences were observed in the overall mean levels of PD and CBL around STIs among CS and NS. However, a statistically significant increase was observed in the mean scores of BOP and PI around STIs in the NS and CS at 12 and 60 months follow-up, respectively. In both groups, the loosening of the implant was the most frequently encountered type of STI failure. The outcomes of the present study suggest that STIs placed in maxillary tuberosity can show reliable clinical, radiographic, and restorative stability among cigarettes smokers and non-smokers. However, the role of smoking status and oral hygiene cannot be disregarded in this scenario.

Disinfection of acrylic denture resin polymer with Rose Bengal, Methylene blue and Porphyrin derivative in photodynamic therapy.

AIM: The study aimed to assess the effect of in-vitro chlorhexidine and antimicrobial photodynamic therapy (aPDT) disinfection protocols against acrylic resin specimens colonized with S. mutans, S. aureus, E. coli, and C. albicans. MATERIAL AND METHODS: Reference strains of S. mutans, S. aureus, E. coli, and C. albicans were tested. Sixteen blocks of acrylic specimens were prepared by heat-cure acrylic resin and contaminated by in-vitro biofilm growth. Specimens in group 1, group 2 and group 3 were treated with Rose Bengal (RB), methylene blue (MB) 500 mg/L and porphyrin derivative (PD) 5 ml respectively, for the sensitization of biofilms. All photosensitizers (PS) were activated by LED at different wavelength. CHX was prepared in sterile distilled water and applied for 60 s. Each contaminated specimen was sprayed on all its surfaces with the aforementioned photosensitizers and control CHX. One-way analysis of variance (ANOVA) model was used to test the effect of the treatments and Tukey multiple comparison tests to compare means OF CFU/mL (log10) for exposed E. coli, C. albicans, S aureus, and S. mutans RESULTS: Specimens treated with 0.12% CHX (control) demonstrated a significant reduction in CFU/mL (log10) for exposed E. coli; 2.04±0.07 CFU/mL, C. albicans; 2.09±0.85 CFU/mL, S aureus; 3.04±0.11 CFU/mL, and S. mutans; 2.54±0.91 CFU/mL. The intragroup comparison revealed E.coli did not exhibit a decrease in reduction CFU/mL (log10) when acrylic resin irradiated with RB 5 µm. Whereas, CFU/mL (log10) values of S.aureus; 3.62±0.68 and S.mutans; 3.41±0.13 plummeted (p<0.05). Intergroup comparison showed E.coli values to display comparable reduction when disinfected with MB 500 mg/L and 0.12% CHX; 3.16±0.34 and 2.04±0.07 CFU/mL (log10) (p<0.05). CONCLUSION: Photosensitizers (RB, MB, PD) are selective in reducing bacterial count on acrylic resin blocks. CHX was found to be effective against all bacteria E.coli, C.albicans, S.aureus, and S.mutans at a concentration of 0.12%.

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.

Dentin Bond Integrity of Filled and Unfilled Resin Adhesive Enhanced with Silica Nanoparticles-An SEM, EDX, Micro-Raman, FTIR and Micro-Tensile Bond Strength Study.

The objective of this study was to synthesize and assess unfilled and filled (silica nanoparticles) dentin adhesive polymer. Methods encompassing scanning electron microscopy (SEM)-namely, energy dispersive X-ray spectroscopy (EDX), micro-tensile bond strength (µTBS) test, Fourier transform infrared (FTIR), and micro-Raman spectroscopy-were utilized to investigate Si particles' shape and incorporation, dentin bond toughness, degree of conversion (DC), and adhesive-dentin interaction. The Si particles were incorporated in the experimental adhesive (EA) at 0, 5, 10, and 15 wt. % to yield Si-EA-0% (negative control group), Si-EA-5%, Si-EA-10%, and Si-EA-15% groups, respectively. Teeth were set to form bonded samples using adhesives in four groups for µTBS testing, with and without aging. Si particles were spherical shaped and resin tags having standard penetrations were detected on SEM micrographs. The EDX analysis confirmed the occurrence of Si in the adhesive groups (maximum in the Si-EA-15% group). Micro-Raman spectroscopy revealed the presence of characteristic peaks at 638, 802, and 1300 cm-1 for the Si particles. The µTBS test revealed the highest mean values for Si-EA-15% followed by Si-EA-10%. The greatest DC was appreciated for the control group trailed by the Si-EA-5% group. The addition of Si particles of 15 and 10 wt. % in dentin adhesive showed improved bond strength. The addition of 15 wt. % resulted in a bond strength that was superior to all other groups. The Si-EA-15% group demonstrated acceptable DC, suitable dentin interaction, and resin tag formation.

Graphene oxide nano-filler based experimental dentine adhesive. A SEM / EDX, Micro-Raman and microtensile bond strength analysis.

AIM: The study aimed to assess graphene oxide (GO) adhesive and its dentin interaction using scanning electron microscopy (SEM), MicroRaman spectroscopy and Microtensile bond strength (µTBS). MATERIALS AND METHODS: Experimental GOA and control adhesives (CA) were fabricated. Presence of GO within the experimental adhesive resin was assessed using SEM and Micro-Raman spectroscopy. Ninety specimens were prepared, sixty teeth were utilized for µTBS, twenty for SEM analysis of interface for CA and GOA and ten were assessed using microRaman spectroscopy. Each specimen was sectioned and exposed dentine was conditioned (35% phosphoric acid) for 10 s. The surface was coated twice with adhesive (15 s) and photopolymerized (20 s). Composite build-up on specimen was photo-polymerized. Among the bonded specimens, thirty specimen were assessed using Micro-Raman spectrometer, SEM and energy dispersive X-ray spectroscopy (EDX), whereas remaining specimens were divided in to three sub-groups (n = 10) based on the storage of 24 h, 8 weeks and 16 weeks. µTBS testing was performed at a crosshead speed of 0.5 mm/min using a microtensile tester. The means of µ-tbs were analyzed using ANOVA and post hoc Tukey multiple comparisons test. RESULTS: No significant difference in µTBS of CA and GOA was observed. Storage time presented a significant interaction on the µTBS (p < 0.01). The highest and lowest µTBS was evident in CA (30.47 (3.55)) at 24 h and CA (22.88 (3.61)) at 18 weeks. Micro-Raman analysis identified peaks of 1200 cm-1 to 1800 cm1, D and G bands of GO nanoparticles in the resin. Uniform distribution of graphene oxide nanoparticles was present at the adhesive and hybrid layer. CONCLUSION: GO showed interaction within adhesive and tooth dentin similar to CA, along with formation of hybrid layer. In ideal conditions (absence of nanoleakage), graphene oxide modified adhesive shows comparable bond strength and durability of resin dentine bond.

Repair strength and surface topography of lithium disilicate and hybrid resin ceramics with LLLT and photodynamic therapy in comparison to hydrofluoric acid.

AIM: The aim was to compare the repair bond strength and surface topography of lithium disilicate ceramics (LDC) and hybrid resin ceramics (HRC) using different surface conditioning treatments [low level laser therapy (LLLT), photodynamic therapy (PDT), hydrofluoric acid (HF) with silane and air abrasion (AA) and silane]. MATERIAL AND METHOD: Sixty specimens each of LDC and HRC were used. Discs were prepared for each group (6 × 2 mm), conditioned using different regimes. Specimens in group 1 and 5 were laser irradiated using Er,Cr:YSGG (ECYL), group 2 and 6 were conditioned using methylene blue photosensitizer (PDT), group 3 and 7 surface was treated with hydrofluoric acid and silane (HFA-S), group 4 and 8 conditioned with Al2O3 air abrasion and silane (AA-S). A Porcelain Repair Kit was used according to manufacturer recommendation in all samples. Peak universal bond adhesive was rubbed on ceramic surface and then bonded with composite resin. For shear bond strength testing the specimens were placed in a universal testing machine. A stereomicroscope at 40x magnification was used to analyse failure pattern. Five specimens in each group after surface treatment were evaluated for surface changes and topography using scanning electron microscopy. The mean repair bond strength was calculated using ANOVA and Tukey's post hoc test at a significance level of (p < 0.05). RESULT: The highest repair bond strength was observed in group 3 (LDC) (20.57 ± 3.58 MPa) (HFA-S), whereas, the lowest score was displayed in Group 2 (LDC) using methylene blue photosensitizer (MBPS) (12.18 ± 1.08 MPa). Similarly, in HRC the highest repair SBS was presented in group 8 (AA-S) (20.52 ± 2.51 MPa) and the lowest SBS values were exhibited by PDT treated group 6 (13.22 ± 0.62 MPa). CONCLUSION: A combination of mechanical and chemical surface treatments should be used in order to achieve adequate repair bond strength between resin composites and ceramic interface of LDC and HRC.

Influence of milling systems and marginal configurations on the fit of yttrium stabilized tetragonal zirconia polycrystals (Y-TZP)' copings.

OBJECTIVE: The aim of this study was to evaluate marginal fit of yttrium tetragonal zirconia polycrystals (Y-TZP)' copings with different finish line designs fabricated with various digital scanners and milling systems. METHODS: Three model plastic teeth were prepared with three finish line designs: Design-1, continuous chamfer; Design-2, chamfer with shallow depression; Design-3, chamfer with deep depression. The "master models" were replicated using elastomeric polyvinyl siloxane impression material and poured in type IV stone generating 90 dies, 30 dies for each design. Dies were scanned and copings were milled utilizing three digital scanners and computer-aided design/computer-aided manufacturing (CAD/CAM) systems: System-1, InEos Red Scan (Sirona Dental Systems, Germany), Vitablocks® Mark II (VITA, Germany) copings milled by Cerec® inLab (Sirona Dental Systems, Germany); System-2, Cerec® AC Connect with BlueCam (Sirona Dental Systems, Germany), Vitablocks® Mark II (VITA, Germany) copings milled by Cerec® inLab (Sirona Dental Systems, Germany); and System-3, NobleProcera™ Optical Scanner (NobleBiocare™), procera zirconia coping milled by a Noble Procera™ milling machine (NobleBiocare™). Copings were seated on their respective "master models" and secured with uniform force. Eight measurements per coping were performed at pre-established points, with a metallurgical microscope (Zeiss, Germany) connected to a high precision digital video-micrometer (Javelin JV6000, California, USA) at 200 × magnification. RESULTS: The tested systems demonstrated marginal gaps ranging from 12.4 to 26.6 µm. Results for marginal fit of milled copings fabricated using three systems with different finish line designs differed significantly (p < 0.05). Procera zirconia copings scanned and milled with NobleProcera™ exhibited significantly lower marginal gaps compared to other specimen groups. However, InEos Red Scan/Vitablocks® Mark II/Cerec® inLab showed maximum marginal gaps among the study specimens. CONCLUSIONS: CAD-CAM manufactured Y-TZP' copings exhibited marginal gaps ranging from 12.49 to 26.6 µm. The CAD-CAM fabrication system was a significant factor influencing the marginal misfit of Y-TZP' copings. Margin design exhibited system dependent influence on the marginal misfit. Marginal misfit observed for all systems were within clinically acceptable parameters.

Bonding integrity and compressive strength of re-bonded, surface conditioned and Er Cr YSGG laser treated lithium disilicate ceramics.

AIM: The aim of the study was to investigate the shear bond strength (SBS) and compressive strength (CS) of Er Cr YSGG laser (ECL) treated, re-bonded lithium disilicate (LD) ceramic in comparison to standard conventional conditioning (hydrofluoric acid (HFA) and silane). METHODS: One hundred LD ceramic disks were divided equally for SBS and CS testing. Eighty samples were conventionally surface treated and bonded to resin cement followed by de-bonding of the cement build-up. All de-bonded specimens were divided into four groups based on re-bonding surface treatments (HFA, primer, adhesive, and ECL). Resin cement build-ups were performed in 40 specimens for SBS testing (universal testing machine); however, the remaining 40 specimens were tested for CS. Ten specimens each were used as controls (surface treatment was performed once and no primary resin cement bonding) for SBS and CS assessment. Surface topography was assessed using a scanning electron microscope. RESULTS: The maximum and minimum SBS values were shown by groups: control (33.42 ± 3.28 megapascals (MPa)); and ECL (17.50 ± 2.22 MPa) respectively. The maximum and minimum CSs were displayed by specimens in the ECL group (439.45 ± 70.68 MPa) and the control group (237.28 ± 19.96 MPa), respectively. For ECL specimens, SBS was significantly lower and CS was significantly higher as compared to control specimens. CONCLUSIONS: Application of the Er Cr YSGG laser significantly improved the CS of de-bonded ceramic specimens. However, it did not show a positive influence on the bond integrity of re-bonded ceramics in comparison to conventional surface treatment regimes.

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.

Assessment of advanced glycation end products in the peri-implant sulcular fluid among moderate cigarette-smokers and nonsmokers with peri-implantitis.

BACKGROUND: It is hypothesized that the levels of advanced glycation end products (AGEs) are higher in the peri-implant sulcular fluid (PISF) of cigarette-smokers than nonsmokers with peri-implantitis. PURPOSE: The purpose was to compare the levels of AGEs in the PISF among moderate cigarette-smokers and nonsmokers with peri-implantitis. MATERIALS AND METHODS: Cigarette-smokers and nonsmokers with peri-implantitis and nonsmokers without peri-implantitis were included. A questionnaire was used to gather information related to smoking habit, duration of implants in function and demographic traits. In all groups, peri-implant plaque index (PI), gingival index (GI), crestal bone loss (CBL) and probing depth (PD). The PISF was collected and levels of AGEs were measured. Group comparisons were performed and P < .01 was nominated as pointer of statistical significance. RESULTS: Fourteen smokers with peri-implantitis (12 males and 2 females), 15 nonsmokers with peri-implantitis (14 males and 1 female) and 15 nonsmokers without peri-implantitis (13 males and 2 females) were included. Smokers with peri-implantitis had a smoking history of 22.7 ± 0.3 pack years. The mesial and distal CBL, PI, and PD were significantly higher in smokers with peri-implantitis than nonsmokers with (P < .01) and without peri-implantitis (P < .01). The GI was significantly higher in smokers (P < .01) and nonsmokers with peri-implantitis (P < .01) compared with nonsmokers without peri-implantitis. The levels of AGEs were significantly higher among smokers with peri-implantitis (552.8 ± 87.2 pg/mL) (P < .01) compared with nonsmokers with (141.6 ± 64.9 pg/mL) and without (88.1 ± 27.3 pg/mL) peri-implantitis. The levels of AGEs were significantly higher among nonsmokers with (141.6 ± 64.9 pg/mL) (P < .01) than without (88.1 ± 27.3 pg/mL) peri-implantitis. CONCLUSION: The levels of AGEs expressed in the PISF are higher among moderate cigarette-smokers than nonsmokers with peri-implantitis.