Clinical Peri-Implant Parameters and Marginal Bone Loss for Early Mandibular Implant Overdentures: A Follow-Up of 60 Months

Background and Objectives: Despite the identified benefits of early implant loading, studies have questioned its advantages compared to delayed loading in edentulous patients. This study aimed to evaluate clinical peri-implant parameters and marginal bone loss around early placed and loaded mandibular implant overdentures with a 60-month follow-up. Materials and Methods: In this prospective cohort study, 43 patients were enrolled to receive 86 early loading sub-crestal dental implants through prosthetic guides. Implant overdentures were supported by two isolated implant locator attachments between two mental foramens. Clinical peri-implant parameters, including plaque index (PI), bleeding index (BI), peri-implant pocket depth (PIPD), and marginal bone loss (MBL) were evaluated using standardized techniques at 1, 12, 24, 36, 48, and 60 months follow-up. At 60 months, complications associated with implant overdentures (IOD's) were noted. The mean comparison of peri-implant clinical parameters was performed through ANOVA test. A p-value of ≤0.05 was taken as significant. Results: Out of the total 43 enrolled patients, 8 patients were lost during follow-up; as a result, 35 patients completed the 5 years follow-up. The mean values of PI, BI, and PIPD increased with no statistical difference (p > 0.05). For marginal bone loss, an increase in the mean values was noted at different time intervals with statistical differences (p < 0.001). The most common complications noted were loosening of the abutment, occlusal adjustment, retentive locator loosening and replacement, and relining of the denture. Conclusions: Early placement of IODs failed to prevent bone loss over time and was associated with complications, predominantly consisting of abutment loosening, occlusal adjustments, broken retentive locator components, relining, and rebasing.

Evaluation of Peri-Implant Parameters and Functional Outcome of Immediately Placed and Loaded Mandibular Overdentures: A 5-year Follow-up Study

PURPOSE

To evaluate the peri-implant parameters of immediately placed and loaded mandibular overdentures over a 5-year follow-up period.

MATERIALS AND METHODS

All subjects who had been advised and planned for two-implant mandibular overdenture treatment were included in this study. The peri-implant parameters -including plaque index (PI), bleeding index (BI) and peri-implant pocket depth (PIPD) as well as marginal bone loss (MBL) - were assessed. In addition, prosthodontic parameters including abutment-, implant- and denture-related complications were assessed. Patients were evaluated at follow-up visits, scheduled at 1, 12, 24, 36, 48, and 60 months. The data distribution was analysed with the Shapiro-Wilk test. Data within follow-up categories were compared using ANOVA and the Tukey-Kramer test. A p-value < 0.05 was considered statistically significant.

RESULTS

Among the 32 participants, 19 were males and 13 were females, with a mean age of 60.5 ± 7.33. The mean plaque index (PI), bleeding index (BI) and peri-implant pocket depth (PIPD) varied over time. However, no statistically significant difference was observed in the plaque index, bleeding index and peri-implant pocket depth over time (p > 0.05). The mean value at baseline was found to be -0.9 ± 0.3. The values increased over time, with the highest value observed at 60 months 2.6 ± 0.7, which was statistically significant (p < 0.001).

CONCLUSION

Immediately placed and loaded mandibular implant overdentures using two un-splinted implants with locator attachments showed acceptable PI, BI and PIPD at the 5-year follow-up. Statistically significantly greater marginal bone loss was observed from baseline to follow-up, but it was within acceptable limits. A moderate number of restorative and abutment complications were observed during the follow-up of IODs.

Clinical, Bacterial, and Prosthodontic Parameters After Implant Abutment Disinfection Using Nd:YAG, Er,Cr:YSGG, Chlorhexidine, and Conventional Steam Before Prosthesis Delivery

Objective: This 1-year prospective clinical trial was designed to assess the microbial, clinical, radiographic, and prosthetic parameters after disinfection of the implant abutment connection using Er,Cr:YSGG (erbium, chromium-doped: yttrium, scandium, gallium, and garnet) and Nd:YAG (neodymium-doped yttrium, aluminum, garnet). Materials and methods: All the patients were divided into four groups; Group I: Nd:YAG laser, Group II: Er,Cr:YSGG laser, Group III: 0.2% chlorhexidine (CHx), and Group IV: steam disinfection. Peri-implant parameters assessed included peri-implant bleeding scores (PIBS), peri-implant plaque scores (PIPS), peri-implant pocket depth (PIPD), and crestal bone loss (CBL). The peri-implant plaque samples were acquired to perform microbiological analysis to assess Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, respectively. All measurements were completed at baseline, 6 months, and 12 months postsurgery. Multiple groups were compared with the help of the Bonferroni post-hoc adjustment test (p < 0.01). Logistic regression models were utilized to assess the association between age, oral hygiene practices (brushing and flossing), and duration of implant function. Results: At the baseline level, there were no discernible differences in the peri-implant parameters between the study groups (p > 0.05). At the 6-month (p < 0.01) and 12-month (p < 0.001) follow-ups, all four study groups demonstrated a significant improvement in PIPS and PIBS, with no significant differences between the groups at baseline (p > 0.05). Based on an intergroup comparison, Group I (Nd:YAG) showed a significant decrease in PIBS when compared with the other groups. Group II showed a considerable decrease in PIPD and enhancements in CBL when compared with Groups I, III, and IV (p < 0.01). At the 6- and 12-month follow-up periods, P. gingivalis and T. denticola reduction were found to be statistically higher in Group II, whereas P. gingivalis and T. forsythia mean log CFU/mL were found to be statistically higher in Group I. Conclusions: Nd:YAG and Er,Cr:YSGG lasers both outperformed CHx and steam disinfection in terms of clinical, peri-implant, and prosthetic results when used to clean implant abutments.

Efficacy of adjunct photodynamic therapy on Candida growth and oral health quality of life in denture stomatitis patients with type 2 diabetes mellitus wearing implant-retained overdentures: a randomized clinical study

AIM

The aim of the present clinical trial was to study the efficacy of combined miconazole and PDT in the improvement of quality of life and levels of Candida species in chronic hyperglycemic patients with denture stomatitis (DS).

METHODS

One hundred patients were randomly divided into five groups; 20 each in the miconazole, PDT, miconazole+ PDT, CHX and distilled water groups. Methylene blue mediated irradiation was conducted using 600nm diode laser with power, energy density and radiance as 100 mW, 3527 mW/cm2 and 9 J, respectively. Patients were advised to apply 2.5 ml of 2% topical miconazole four times a day. The existence of Candida spp. was detected by means of microbiological culture technique. Candida colony counts from the palates and dentures surfaces, quantified as colony forming unit (CFU)/mL were evaluated at baseline, end of 14 days, 28 days and 60 days. Oral health related quality of life was assessed with the help of a questionnaire.

RESULTS

The quality of life showed significant improvement in the group where combination treatment was executed. The overall CFU/mL values were greater in the dentures in comparison to those from the palates of the patients of all the five groups. During all time periods of the study, the CFU/mL values obtained from combination treatment group showed significant differences. Candida albicans was the most predominant yeast.

CONCLUSION

This study showed the effectiveness of methylene blue- PDT in combination with miconazole in improving oral health related quality of life and significantly reducing Candida CFU counts to resolve palatal inflammation in diabetic individuals with implant-supported complete dentures.

Comparison of the postoperative anti-inflammatory efficacy of chlorhexidine, saline rinses and herbal mouthwashes after mechanical debridement in patients with peri-implant mucositis: A randomized controlled trial

AIM

The null hypothesis is that there is no difference in the post-operative anti-inflammatory efficacy of chlorhexidine (CHX), 2% saline rinses (SR) and a herbal mouthwash (MW) after non-surgical mechanical debridement (MD) for treatment of peri-implant mucositis (PiM). The aim was to compare the post-operative anti-inflammatory efficacy of CHX, 2% SR and a herbal oral rinse after non-surgical MD of PiM.

MATERIALS AND METHODS

The present randomized controlled trial had a single-blinded parallel arm design. Patients diagnosed with PiM were enrolled. Demographic information was recorded. All patients underwent MD and were randomly divided into 4 groups: CHX-group: 0.12% non-alcoholic CHX; Sodium chloride (NaCl) group: 2% NaCl rinses; Herbal MW group: Herbal-based MW and H₂ O group: distilled water with peppermint flavour. After MD, all the participants were advised to rinse twice daily (every 12 hrs) for 2 weeks with their respective MWs. In all groups, peri-implant modified plaque index (mPI), modified gingival index (mGI) and probing depth (PD) were measured at baseline and at 12 weeks of follow-up. Sample size was estimated using data from a pilot investigation; and group-comparisons were performed. Statistical significance was confirmed when P-values were below 0.01.

RESULTS

Sixty individuals (15 patients/group) were included. At baseline, mPI, mGI and PD were comparable in all groups. At baseline, there was no significant difference in peri-implant mPI, mGI and PD in all groups. At 12-weeks' follow-up, there was a statistically significant reduction in peri-implant mPI (p < 0.01), mGI (p < 0.01) and PD (p < 0.01) in CHX, NaCl and herbal MW groups compared with H₂ O group. There was no significant relation between implant location, duration for which, implants were functional, gender and peri-implant clinical parameters in all groups.

CONCLUSION

After non-surgical MD, post-operative use of CHX and herbal and NaCl MWs is useful for the management of PiM in the short-term.

Efficacy of subgingival minocycline hydrochloride delivery as an adjunct to non-surgical mechanical debridement for the treatment of peri-implantitis in patients with type-2 diabetes mellitus

OBJECTIVE

The aim was to assess the efficacy of subgingival minocycline hydrochloride (MH) delivery with non-surgical mechanical debridement (NSMD) for treating peri-implantitis in patients with type-2 diabetes mellitus (DM).

PATIENTS AND METHODS

Type-2 diabetic and non-diabetic patients with peri-implantitis were included. In the test-group, patients underwent NSMD with a single session of MH delivery. In the control-group, patients underwent NSMD alone. Hemoglobin A1c (HbA1c), modified plaque-index (mPI), modified gingival index (mGI), probing-depth (PD) and crestal bone loss (CBL) were measured at baseline and at 6-month follow-up. Level of significance was set at p<0.01.

RESULTS

Thirty type-2 diabetic and 30 healthy individuals with peri-implantitis were included. There was a significant reduction in mPI (p<0.01), PD (p<0.01) and mGI (p<0.01) at 6 months among patients with and without type-2 DM in the test and control groups. There was no significant difference in peri-implant parameters in all patients at the 6-month follow-up. There was no significant difference in HbA1c and CBL among patients with and without type-2 DM in the test and control groups when baseline values were compared with those at 6 months of follow-up.

CONCLUSIONS

A single application of subgingival MH delivery is as effective as NSMD alone for the treatment of peri-implantitis in type-2 diabetic patients.

Comparison of Whole Salivary Cortisol and Interleukin 1-Beta Levels in Light Cigarette-Smokers and Users of Electronic Nicotine Delivery Systems before and after Non-Surgical Periodontal Therapy

There are no studies that have compared whole salivary cortisol (CL) and interleukin 1-beta (IL-1β) levels in cigarette-smokers (CS) and electronic nicotine delivery systems (ENDS)-users before and after non-surgical periodontal therapy (NSPT). The aim was to compare whole salivary CL and IL-1β levels in light CS and ENDS users before and after non-surgical periodontal therapy (NSPT). Self-reported current CS, ENDS users, and non-smokers were included. A questionnaire was used to collect demographic data. All patients underwent NSPT. Periodontal parameters (probing depth (PD], gingival index (GI], clinical attachment loss (AL], plaque index (PI], and marginal bone loss (MBL]) and whole salivary CL and IL-1β were measured at baseline. At 3-months of follow-up, clinical parameters and whole salivary CL and IL-1β were re-assessed. p-values < 1% were arbitrated as statistically significant. Fifty-four individuals (18 CS, 18 ENDS users, and 18 non-smokers) were included. Clinical AL, MT, PD, PI, and MBL were similar in all groups at baseline. At 12-weeks of follow-up, PI (p < 0.01) and PD (p < 0.01) were high in CS and ENDS-users than non-smokers. Among non-smokers, there was a statistically significant correlation between whole salivary cortisol and IL-1β levels at 12-weeks' follow-up (p < 0.001). There was no difference in whole salivary cortisol and IL-1β levels in CS and ENDS users at baseline and at 12-weeks follow-up. At 12-weeks of follow-up, there was a significant reduction in IL-1β (p < 0.01) and CL (p < 0.01) than baseline. In light CS and ENDS users without periodontal disease, clinical periodontal parameters and whole-salivary CL and Il-1β levels remain unchanged after NSPT.

Efficacy of adjunct subgingival minocycline delivery for treatment of peri-implantitis in moderate cigarette smokers

OBJECTIVE

Localized subgingival minocycline hydrochloride (MH) delivery as an adjuvant to with non-surgical mechanical debridement (NSMD) is useful for the treatment of periodontitis; however, there are no trials that have assessed the efficacy of subgingival MH delivery with NSMD for the treatment of peri-implantitis in cigarette-smokers and non-smokers. This randomized controlled trial assessed the efficacy of subgingival MH delivery with NSMD for the treatment of peri-implantitis in cigarette-smokers.

PATIENTS AND METHODS

Self-reported current cigarette-smokers and non-smokers with peri-implantitis were encompassed. These individuals were subdivided into 2-subgroups. Patients in test- and control groups received NSMD with and without a single delivery of subgingival MH. Modified-gingival-index (mGI), modified-plaque-index (mPI), probing-depth (PD) and crestal-bone-loss (CBL) were measured at baseline and at 6-months' follow-up. Demographic-data was also collected. Level of significance was set at p<0.01.

RESULTS

Twenty-four cigarette-smokers and 24 non-smokers with peri-implantitis were included. There was a significant reduction in mPI (p<0.01), mGI (p<0.01), PD (p<0.01) at 6-months among patients with and without type-2 DM in test- and control-groups. There was no significant difference in peri-implant mPI, PD and mGI, patients with and without type-2 diabetes in test- and control-groups at 6-months of follow-up. There was no significant difference in CBL in all patients at 6-months of follow-up.

CONCLUSIONS

A single application of subgingival MH delivery is as effective as NSMD alone for the treatment of peri-implantitis in cigarette-smokers and non-smokers.

Association of the Unstimulated Whole Salivary Cytokine IL-1β Levels with Initial, Moderate and Severe Periodontitis. A Case Control Study

Periodontitis (P) is a highly prevalent inflammatory disease of the oral cavity. The objective of the study was to evaluate the stages of pro-inflammatory cytokine IL-1β in initial, moderate and severe periodontitis. One hundred and twenty two patients were included in the study. Periodontitis subjects had at least 20 natural teeth and ≥8 sites with pocket depths of >4 mm and clinical attachment loss (CAL). A questionnaire was used with respect to the socio demographic parameters which included age, gender, ethnicity, education, marital, residence and occupation. To categorize the severity of the disease, teeth were assessed for, Plaque index (PI), Bleeding on probing (BOP), CAL, missing tooth, tooth mobility and bone loss. Unstimulated whole saliva (UWS) was collected and Interleukin-1β (IL-1β) cytokine levels were analyzed using enzyme linked immunosorbent assay with microplate reader at 450 nm. Clinical parameters and salivary cytokine concentrations were assessed using one-way analysis of variance, whereas a correlation of cases with gender and severity of periodontitis was evaluated using chi-square test. Fifty-nine patients were healthy controls and 63 were periodontitis patients Thirty two percent (n = 20) had initial periodontitis, 40% (n = 25) suffered from moderate and 29% (n = 18) had severe periodontitis. Periodontitis subgroups were significantly different with regards to age and gender (p < 0.001). The mean PPD and CAL among the periodontitis patients (PPD, 3.52 ± 1.25 mm; CAL, 4.04 ± 1.64 mm) were significantly compromised (p < 0.05) compared to healthy controls (PPD, 1.52 ± 0.73 mm; CAL, 0.08 ± 0.28 mm). Increased levels of IL-1β were associated with high CAL and PPD findings. UWS IL-1β levels were higher in periodontitis patients compared to healthy individuals. In addition, cases of severe periodontitis showed significantly higher UWS IL-1β levels compared to initial and moderate periodontitis patients. Comparative levels of salivary IL-1β can be potentially used as a diagnostic tool for periodontitis identification and disease progression along with clinical parameters.

Shear bond characteristics and surface roughness of poly-ether-ether ketone treated with contemporary surface treatment regimes bonded to composite resin

AIM

To evaluate and compare the influence of contemporary surface treatments of air abrasions, sulfuric acid, and Photodynamic therapy (PDT) on the adhesive bonding and surface roughness of Poly-ether-ether-ketone (PEEK) bonded to resin composite.

MATERIAL AND METHODS

One hundred and fifty PEEK (disc-shaped) specimens of 10 mm diameter and 2mm thickness were prepared. Specimens were subjected to the following surface treatments, Control (no treatment), PDT, air abrasion using Alumina particles (110 μm) (AA-AP), Sulfuric acid (SA), and air abrasion using diamond particles (10-20 μm) AA-DP. Surface roughness (Ra) of treated samples were evaluated using surface profilometer. Universal testing machine was used to evaluate shear bond strength after composite resin build-up. Stereomicroscope was utilized for failure analysis of de-bonded samples of all five groups. Statistical analysis was performed utilizing one-way analysis of variance (ANOVA) to measure means and standard deviations of SBS among studied groups and the means of SBS were paralleled by Tukey multiple comparison tests (p>0.05).

RESULTS

The highest SBS was observed by 98% SA (19.25 ± 0.68 MPa). While specimen treated with PDT (11.69 ± 0.12 MPa) showed the lowest SBS. PEEK surface, treated with PDT and AA-DP demonstrated comparable SBS (p>0.05). PEEK when pretreated with 98% SA (2.658 ± 0.658μm) exhibited a significantly higher Ra value as compared to other surface-treated groups (p< 0.05).

CONCLUSION

PEEK surface treated with SA showed the highest SBS and surface roughness compared to other groups. Surface roughness of PEEK treated with PDT, AA-AP, and AA-DP demonstrated no difference in Ra. PEEK surface treatment technique should be further investigated to develop reliable adhesive resin bonding.

Knowledge attitude and practice of safety measures for corona virus disease - 19 (COVID-19) among general population

Objective

To evaluate the knowledge, attitude, and practice of general population for Corona virus disease 19 (COVID-19).

Methods

A total of 950 participants submitted an online self-administered questionnaire, which was developed through literature search and validated. The online survey link was distributed through various social media platforms (WhatsApp, Instagram, Facebook, LinkedIn, Twitter, Snapchat, Pinterest, and Tumblr). And 861 forms were included in the study after checking for completion of relevant response from participants, whereas 89 forms were excluded. The data were analyzed through Statistical Package for Social Sciences. Descriptive statistics were performed for percentage and frequency determination of quantitative and qualitative variables. Spearman's correlation and Chi square test were performed to control confounders and association of knowledge, attitude, and practices with gender and education level. The P value <0.05 was considered as statistically significant.

Results

More than two third of the population was aware of COVID-19 and three fourth had had bachelor's degrees, whereas 18% had master level education. 85% have not attended any courses, awareness campaigns, and lectures to inculcate recent and updated knowledge. 83% believed that COVID-19 is a serious threat to the community; hence, prevention strategies should be adopted. There was no significant relationship (p = 0.23) between knowledge, attitude, and practice levels with gender, whereas a significant relationship (p = 0.01) was noted with education of participant. Similarly, a significant relationship (p = 0.00) was seen between knowledge and practices of participants toward COVID-19.

Conclusion

The studied population displayed adequate knowledge, attitude, and practice to combat COVID-19. However, we also find a knowledge gap between information source and perception of COVID-19 among our study participants. Therefore, there is a critical need for effective education and widespread public campaigns aiming to enhance relevant and contemporary information related to prevention and management of COVID-19.

Bond Integrity of Titanium Surface to Resin Cement After Conditioning with Different Photobiomodulataion Therapy (PBT)

The aim of the present study was to evaluate the efficacy of interfacial bonding between resin cement and titanium alloy conditioned with different Photobiomodulataion Therapy (PBT) in comparison with conventional regimes. Seventy-five samples of titanium bar were segmented polished; and based on conditioning regime divided into five groups (15 each specimens). Group 1: No treatment (control), Group 2: Sand blasting with 120 µm Al2O3, Group 3: Er,Cr:YSGG (ECL), Group 4: Er:YAG laser (EYL), Group 5: Nd:YAG laser (NYL). After different conditioning regimes, resin cement was mixed and applied. All specimens were thermocycled for 500 cycles and positioned on universal testing machine for shear bond strength testing. Modes of failure was assessed by a single examiner using stereomicroscope at 40× magnification. Three pairs of specimens in each group were sputter coated and scanning electron microscope (SEM) images were taken at 1000× magnification using 20 Kv. The highest SBS values were observed in group 2 (14.25±2.29 MPa) and the lowest bond values were displayed in group 1 (6.98 ±0.59 MPa). Titanium alloy abutments conditioned with different laser prototypes ECL (11.22±1.40 MPa), EYL (9.29±1.22 MPa) and NYL (9.12 ±1.84 MPa) exhibited comparable SBS (p > 0.05). Adhesive failures were primarily dominant among all experimental groups. Photo-biomodulation in the form of ECL lasers has the potential to be used as a supplement to sandblasting procedure in conditioning of cement retained titanium alloy implant abutments.

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.

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.

Influence of contemporary CAD-CAM milling systems on the fit and adaptation of partially stabilized Zirconia fixed partial dentures

Objective:

To evaluate marginal fit and internal adaptation of three-unit Zr frameworks fabricated from four Zr CAD/CAM milling systems.

Methods:

Fixed partial denture models were replicated (40 stone models) using Polyvinyl Siloxane impression material (PVS) and type IV stone for Zr framework fabrication. FPDs were milled with four CAD/CAM systems, Group-II: LAVAL Zirconia milled by LAVA , Group-2: Vita In-Ceram YZ milled by Cerec®, Group-3: Zirconia milled by GM1000 and Group-4: Zirconia milled by DWX-50N. Twelve marginal gap measurements per framework were performed at pre-established points, with a metallurgical microscope (Zeiss, Germany) at 500X magnification. Eight measurements of cement space per section were performed for adaptation. Data was analyzed using ANOVA and Tukey post hoc test.

Results:

Zirconia FPD frameworks exhibited gaps ranging from 16 to 50.1 µm for marginal fit and 26.8 to 102.5 µm for internal adaptation. Group-3 [20.8 (8.3) µm & 50.3 (11.4) µm] and Group-4 [16.0 (4.0) µm & 40.2 (8.8) µm] specimens showed significantly lower marginal fit and internal adaptation gaps compared to Group-I [50.1 (13.4) µm & 100.5 (16.7) µm] and Group-2 [38.9 (8.2) µm & 102.5 (13.4) µm] specimens respectively.

Conclusions:

Different CAD-CAM systems for fabrication of Zr FPD frameworks displayed a significant influence on marginal fit and internal adaptation of restorations.

Color Masking Ability of Lithium Disilicate Ceramic for Titanium Alloy Implant Abutments

The aim was to assess the acceptable thickness of monolithic Lithium Disilicate (LD) ceramic in masking of Titanium (Ti) implant abutment by comparison to Zirconium (Zr) crowns through color matching. Forty LD and 10 Zr copings (control) using Hot-pressing and CAD-CAM techniques were fabricated. A standard Ti abutment (Straumann, ITI, Basel, Switzerland) was used as foundation substrate. LD crowns were divided into different thickness [1.0 mm (n = 10), 1.2 mm (n = 10), 1.5 mm (n = 10) and 1.8 mm (n = 10)] and 10 Zr copings (control) had 0.5 mm thickness. Different crown materials and crown thicknesses resulted in 5 study groups designated as Zr-Ti-0.5, LD-Ti1.0, LD-Ti-1.2, LD-Ti-1.5 and LD-Ti-1.8. Specimens were cemented to Ti abutments and using a spectrophotometer the difference of color for specimen and controls was determined by comparing ΔL, Δa and Δb (CIELab color system) and an overall ΔE. These were statistically compared using analysis of variance and Tukey post hoc multiple comparisons. Among LD specimens with Ti abutments, lowest color difference was achieved for LD-Ti-1.8 (2.3 ± 0.31) and the highest color difference was for LD-Ti-1.0 (4.93 ± 0.45). The lowest ΔE was recorded for Zr copings (control), which was lower than (p < 0 01) LD crowns of 1.0 and 1.2 mm thickness. LD crown thickness had a significant effect on ΔE (color difference) on Ti abutments. Masking of Ti abutments by 1.5 mm LD crowns was comparable to Zr specimens (control). Lithium disilicate crown of 1.5 mm thickness showed statistically comparable color stability to 0.5 mm Zr copings on Ti implant abutments.

Clinical, radiographic, and restorative peri-implant measurements of narrow and standard diameter implants in obese and nonobese patients: A 3-year retrospective follow-up study

BACKGROUND

There is dearth of studies assessing clinical, restorative, and radiographic peri-implant outcomes around narrow diameter implants (NDIs) and standard diameter implants (SDIs) in obese and nonobese subjects.

OBJECTIVE

To assess clinical, restorative, and radiographic parameters of NDIs and SDIs placed in obese and nonobese individuals.

MATERIALS AND METHODS

Obese and nonobese patients requiring NDIs and SDIs in the anterior maxilla/mandible were included. Based on the implant diameter, participants were further divided into two subgroups: (a) NDIs (3.3 mm) and (b) SDIs (4.1 mm). Peri-implant clinical measurements including plaque index (PI), bleeding on probing (BOP), probing depth (PD), and radiographic crestal bone loss (CBL) were evaluated around NDIs and SDIs at 1 and 3-year follow-up.

RESULTS

A total of 70 patients (35 obese and 35 nonobese) were included. Only BOP showed statistically significant differences between both the groups at patient level at 1 and 3-year follow-up (P < .05). There was no statistically significant difference in PI and PD around NDIs and SDIs between obese and nonobase patients. Statistical significant differences were observed in the total CBL around NDIs and RDIs among obese and nonbase subjects at 3 year follow-up (P < .05).

CONCLUSION

Both NDIs and SDIs show consistent clinical stability among obese and nonobase patients. Higher amount of bone loss was observed in obese patients compared to nonobase patients despite regular hygiene maintenance.

Clinical performance of one-piece zirconia dental implants: A systematic review

The aim of the present review was to evaluate the clinical and radiographic performance of one-piece zirconia implants (O-PZI). This review followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analysis) guidelines that addressed the following focused question: What is the overall clinical and radiographic performance of O-PZI? The MEDLINE, EMBASE, Cochrane Central Register of Controlled Trials, and Cochrane Oral Health Group Trials Register databases were searched. Six clinical studies were included. For studies evaluating O-PZI compared with one-piece titanium implants, zirconia implants showed higher crestal bone loss (CBL) in both the studies. However, one study demonstrated a high failure rate compared to titanium dental implants, while one study demonstrated comparable survival rates between zirconia and titanium dental implants. For studies evaluating O-PZI for the restoration of single crown and fixed dental prostheses, O-PZI showed comparable bone loss and survival rates for single crowns and fixed dental prostheses. Two studies were included that compared O-PZI with two-piece zirconia (T-PZI). One study showed a higher CBL and low survival rate for O-PZI compared to T-PZI, whereas the other study demonstrated comparable CBL and survival rates between O-PZI and T-PZI. It is still debatable whether O-PZI demonstrate better clinical performance when compared with titanium implants or two-piece design.

Peri-implant parameters, tumor necrosis factor-alpha, and interleukin-1 beta levels in vaping individuals

BACKGROUND

To the author's knowledge, there has been no study that has assessed clinical, radiographic, and immunological peri-implant parameters among individuals vaping e-cigarette (e-cig).

PURPOSE

This pilot study aimed to compare clinical and radiographic peri-implant parameters and levels of tumor necrosis factor alpha (TNF-α) and interleukin (IL)-1β levels among individuals vaping e-cigs and never smoker (NS).

MATERIALS AND METHODS

Forty-seven individuals vaping e-cigs (group-1) and 45 NS (group-2) were included. Demographic and implant-related data were collected using a structured baseline questionnaire. Peri-implant plaque index (PI), bleeding on probing (BOP), and probing depth (PD) were recorded and peri-implant bone loss (PIBL) were assessed using standardized digital radiographs. Enzyme-linked immunosorbent assay was used to assess the levels of TNF-α and IL-1β in peri-implant sulcular fluid.

RESULTS

Bleeding on probing showed statistically significantly higher values in group-2 patients as compared to group-1 patients (P < .01). Probing depth ≥ 4 mm and PIBL was statistically significantly higher in group-1 patients as compared to group-2 patients (P < .05). Mean concentrations of TNF-α (P < .001) and IL-1β (P < .01) were statistically significantly increased in individuals in group 1 as compared with group 2. A significant positive correlations were found between TNF-α levels and BOP (P = .024) and PIBL (P = .016); and significant positive correlation was found between IL-1β and PIBL (P = .018) in group 1, respectively.

CONCLUSIONS

Clinical and radiographic peri-implant parameters are compromised among vaping individuals. Increased levels of proinflammatory cytokines in peri-implant sulcular fluid may suggest greater local inflammatory response in vaping individuals for peri-implant inflammation.