Feasibility of Immediate Implant Placement in Maxillary First Premolars: Prediction of Implant Locations Using Restorations- A Radiographic Study.

BACKGROUND: Maxillary premolars have a unique anatomical location. This is an CBCT based study where the suitability of maxillary premolars for immediate implant placement (IIP) is evaluated. Based on prosthetically driven treatment treatment planning a simple classification system is put forth. MATERIALS AND METHODS: 150 CBCTs of maxillary first premolars were analysed in BlueskyBio software. The topographic position of the tooth was determined by analysing the dimensions of the buccal and lingual cortical plates, the distance between the bucco-lingual plates and the residual bone height from the root apex to the floor of the sinus. Virtual placement of an implant was carried out such that the implant would be positioned 1 mm apical to the buccal bone crest, would engage 3 mm of bone apical to the root apex, and would have a trajectory so that the abutment access was from the central fossa. Four categories were identified and the classification was proposed. RESULTS: It was observed that 74% of cases had buccal bone<1mm,26% had buccal bone >1mm. 79% cases had an average distance >3mm between root apex and maxillary sinus, 21% had an average distance of root apex and maxillary sinus <3mm. The categorizations of implant placement were as follows -Type 1- 24%, Type 2- 56.6%, Type 3-43.3%, Type 4- 0%. CONCLUSIONS: In majority of maxillary 1st premolars an IIP is possible with the implants to be placed in the palatal sockets or the furcation area. In cases were the buccal plate thickness is inadequate, simultaneous grafting should be considered between the implant position and buccal plate.

The 'One Customized Abutment One Time' concept - An innovative technique for optimizing immediacy and digital protocols.

Disconnection and reconnection of abutments multiple times have known to affect the mucosal barrier around implants leading to marginal bone loss. This clinical report describes a novel technique that amalgamates the benefits of digital technologies encompassing the fabrication of surgical guides for implant placement, customized hybrid zirconia abutments and all ceramic lithium disilicate crowns prior to implant placement. A correct 3-dimensional implant positioning along with immediate placement of the definitive hybrid customized abutment and a lithium disilicate crown has the potential to reduce treatment time, visits and costs while delivering optimal esthetic outcomes.

Comparative Evaluation of Marginal Bone Levels, ISQ Trends, and Implant Survival Rates Between Conventional Drilling and Osteotome Technique Using Implants of Varied Lengths: A Split-Mouth Randomized Controlled Clinical Trial.

PURPOSE: To assess marginal bone loss (MBL) and implant stability when implant site preparation is performed with conventional drilling and the osteotome technique in the posterior maxilla. MATERIALS AND METHODS: In total, 30 patients (mean age: 46.97 + 7.48 years) receiving 60 implants were enrolled in this study. In each patient, implant site preparation was done using either conventional drilling (conventional group; n = 30) or the osteotome technique (osteotome group; n = 30). The implant sites were further divided into groups based on the implant length used (implant length < 10 mm, implant length ≥ 10 mm). Marginal bone levels and implant stability quotient (ISQ) values were evaluated at the time of crown insertion and 1 year later. Independent t test and paired t test were used for intergroup and intragroup comparison, respectively. RESULTS: The osteotome group showed statistically significant higher initial ISQ (ISQi) and final ISQ (ISQf) values (ISQi: 61 ± 3.6; ISQf: 64.08 ± 3.7) compared to the conventional group (ISQi: 58.01 ± 4.6; ISQf: 61.32 ± 4.8). Statistically significant higher mean MBL was noted in the conventional group (-0.33 ± 0.12 mm) compared to the osteotome group (-0.26 ± 0.10 mm). Higher MBL was noted in the osteotome group (-0.32 ± 0.09 mm) compared to the conventional group (-0.30 ± 0.14 mm) for implants shorter than 10 mm. For implants ≥ 10 mm in length, significantly higher MBL was noted in the conventional group (-0.37 ± 0.09 mm) compared to the osteotome group (-0.19 ± .06 mm). CONCLUSIONS: Osteotome technique could be used as an alternative to conventional drilling, especially when implants longer than 10 mm are planned in the posterior maxilla.

Evaluation of shear bond strength and translucency of zirconia-reinforced lithium silicate and lithium disilicate: An in vitro study.

Aim: To analyze the effect of various surface treatment protocols on shear bond strength between the ceramic and resin cement (RC) and influence of zirconia on the translucency of LD as compared to zirconia-reinforced lithium silicate (ZLS). Setting and Design: In-Vitro Study. Materials and Methods: Specimens (14 mm × 12 mm × 2 mm) (n = 135) and (14 mm × 12 mm × 1 mm) (n = 45) of ZLS computer-aided design/computer-aided manufacturing glass ceramic block and LD were fabricated, respectively. All the ZLS specimens were crystallized and were tested for the translucency parameter and ceramic-resin shear bond strength. Two different types of surface treatment were used on the ZLS and LD samples. The specimens were treated using the hydrofluoric acid (HF) etching or air abrasion with diamond particles (DPs). The specimens were then bonded using self-adhesive RC to a composite disc of 10 mm and thermocycling was performed. A universal testing machine was used to evaluate ceramic-resin shear bond strength after 24 h. The translucency of the specimens was evaluated using the spectrophotometer by calculating the difference in color between the readings over a black background and a white background. Statistical Analysis Used: Data were statistically analyzed using the independent sample t-test and analysis of variance with Bonferroni's correction and comparison was made between the specimens. Results: Independent sample t-test demonstrated statistically significantly higher translucency for group ZLS (61.44 ± 22) as compared to group LD (20.16 ± 8.39) (P < 0.001). Group ZLS showed statistically significant higher shear bond strength when surface treatment using HF or air abrasion with synthetic DPs was performed as compared to untreated group (3.58 ± 0.45) (P < 0.001). Moreover, air abrasion group (16.79 ± 2.11 megapascal [MPa]) demonstrated statistically significant higher shear bond strength as compared to HF etched group (8.25 ± 0.30 MPa) (P < 0.001). Furthermore, statistically significant higher shear bond strength was noted when air abrasion was done for group ZLS (16.79 ± 2.11 MPa) as compared to group LD (10.82 ± 1.92 MPa) (P < 0.001). However, on surface treatment with HF, a statistically significantly lower shear bond strength was noted for group ZLS (8.25 ± 0.30 MPa) as compared to group LD (11.29 ± 0.58 MPa) (P = 0.001). Conclusion: ZLS demonstrated higher translucency compared to LD restorations. DP abrasion of ZLS is recommended to achieve higher shear bond strength between the ceramic and RC.

In-Vitro Evaluation of Photofunctionalized Implant Surfaces in a High-Glucose Microenvironment Simulating Diabetics.

The present study aimed to assess the efficacy of photofunctionalization on commercially available dental implant surfaces in a high-glucose environment. Discs of three commercially available implant surfaces were selected with various nano- and microstructural alterations (Group 1-laser-etched implant surface, Group 2-titanium-zirconium alloy surface, Group 3-air-abraded, large grit, acid-etched surface). They were subjected to photo-functionalization through UV irradiation for 60 and 90 min. X-ray photoelectron spectroscopy (XPS) was used to analyze the implant surface chemical composition before and after photo-functionalization. The growth and bioactivity of MG63 osteoblasts in the presence of photofunctionalized discs was assessed in cell culture medium containing elevated glucose concentration. The normal osteoblast morphology and spreading behavior were assessed under fluorescence and phase-contrast microscope. MTT (3-(4,5 Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) and alizarin red assay were performed to assess the osteoblastic cell viability and mineralization efficiency. Following photofunctionalization, all three implant groups exhibited a reduced carbon content, conversion of Ti4+ to Ti3+, increased osteoblastic adhesion, viability, and increased mineralization. The best osteoblastic adhesion in the medium with increased glucose was seen in Group 3. Photofunctionalization altered the implant surface chemistry by reducing the surface carbon content, probably rendering the surfaces more hydrophilic and conducive for osteoblastic adherence and subsequent mineralization in high-glucose environment.

Evaluation of Oral Health-Related Quality of Life and Patient Satisfaction in Three-Implant-Retained Mandibular Overdentures: A Randomized Crossover Clinical Trial.

PURPOSE: To assess oral health-related quality of life (OHRQoL) and patient satisfaction with a three-implant-retained mandibular overdenture. MATERIALS AND METHODS: In this randomized crossover clinical trial, 20 edentulous patients received a new set of conventional complete dentures (CDs; baseline). Subsequently, three implants were placed in the anterior mandible: two were placed in the canine regions bilaterally and one in the midline. After successful osseointegration, CDs were attached to the implants using resilient attachments. The overdenture was retained either by three implants (test group) or two implants (control group). The sequence of treatment was randomized such that each patient experienced both treatment options for 6 months each. OHRQoL was assessed at baseline and after 6 months of function for each treatment option using the Oral Health Impact Profile (OHIP-14) and visual analog scale (VAS) scores. Statistical analyses were performed using Friedman and Wilcoxon signed rank tests. RESULTS: CD resulted in significantly higher OHIP-14 and VAS scores (25.25 + 6.42, 8.55 + 1.73) compared to both the control group (11.15 + 5.39, 4 + 2; P < .001) and the test group (6.25 + 4.02, 2.06 + 1.48; P < .001). Similarly, significantly higher mean OHIP-14 and VAS scores were noted for the control group compared to the test group (P < .001). CONCLUSIONS: Overdentures retained by three implants resulted in better OHRQoL scores and higher patient satisfaction compared to overdentures retained by two implants and CDs. Int J Prosthodont 2023;36:554-56.

Effects of surface modification techniques on zirconia substrates and their effect on bonding to dual cure resin cement - An in- vitro study.

Aim: This study aims to evaluate the effect of different surface treatments of monolithic zirconia on the bond strength of resin to zirconia and, to explore alternative methods to improve this bonding. Settings and Design: In-Vitro study. Materials and Methods: Fifty rectangular sintered blocks of Yttria-stabilized Tetragonal Zirconia Polycrystal ceramics of dimensions were milled and sintered. These specimens were further divided into five groups (control, air abrasion, etching with primer application, air abrasion with primer application and novel glass infiltrated zirconia surface group), containing 10 samples each. The specimens were analyzed for surface roughness, tensile bond strength to resin cements, and adhesive and cohesive mode of failures. Statistical Analysis Used: ANOVA and Post-Hoc Tukey test was perform to evaluate the significant differences in the mean values of the groups. Results: Air-abraded samples showed the highest surface roughness (4.95 ± 0.65) (P < 0.05). The group with air abrasion followed by primer application showed the highest tensile bond strength (7.12 ± 0.69) (P < 0.05). The lowest surface roughness (0.638 ± 0.8093) and tensile bond strength (2.03 ± 0.58) was seen in samples that were subjected to etchant treatment followed by application of methacryloyloxydecyl di-hydrogen phosphate (MDP) primer. The changes in comparison to the control group were statistically insignificant (P > 0.05). Except Groups A (control) and C (etchant followed by primer), all other groups showed a cohesive failure. Conclusion: Air abrasion of the zirconia surface with 50 µm alumina particles increases the surface roughness without damaging the surface. Air abrasion followed by MDP primer application is the recommended method of surface treatment to achieve superior bonding. Glass infiltration also showed promising results in terms of tensile bond strength.

Do digital impressions have a greater accuracy for full-arch implant-supported reconstructions compared to conventional impressions? An in vitro study.

Aim: The purpose of this study was to compare the accuracy of conventional implant impressions with digital impression techniques made using two different intraoral scanners. Setting and Design: In-Vitro study. Material and Methods: A scan of master cast containing four implants was made using two intraoral scanners: CEREC Primescan (Dentsply Sirona, USA) and 3Shape Trios (Copenhagen, Denmark) with PEEK scan bodies attached to the implants. Model was scanned ten times using different scanners. The accuracy of the chairside scanners was compared with highly accurate laboratory scanner. The scans were transferred into the software (Geomagic Control X 20, 3D Systems, Rock Hill, SC, USA) for analysis. The linear deviations and the angular deviations between the scans (scan of each model made using high-definition scanner and the master model scan) were calculated to determine the accuracy. Trueness was used as a parameter to compare the accuracy of different scanners (comparing test and reference). Statistical Analysis: Analysis of variance was performed with Bonferroni's post hoc test for multiple group comparisons. Results: Distribution of the mean overall absolute linear deviation was significantly lower in the conventional impression group compared to the CEREC Primescan scanner group and 3Shape Trios group (P < 0.05 for both). Distribution of the mean overall absolute linear deviation was significantly lower in the CEREC Primescan scanner group compared to the 3Shape Trios group (P < 0.05). Distribution of the mean overall absolute angular deviation did not differ between the three groups (P > 0.05 for all). Conclusion: Conventional impressions showed significantly greater accuracy compared to the digital impressions made with both the above intraoral scanners for implant-supported restoration of an edentulous arch. In addition, the digital impressions with the CEREC Primescan scanner showed greater accuracy as compared to the 3Shape Trios scanner.

A Comparative Study on Simulated Chairside Grinding and Polishing of Monolithic Zirconia.

This study evaluated the effects of different simulated chairside grinding and polishing protocols on the physical and mechanical properties of surface roughness, hardness, and flexural strength of monolithic zirconia. Sintered monolithic zirconia specimens (15 mm × 3 mm × 3 mm) were abraded using three different burs: diamond bur, modified diamond bur (zirconia specified), and tungsten carbide bur, along with a group of unprepared specimens that served as a control group. The study was divided into two phases, Phase 1 and Phase 2. Surface roughness, surface hardness, and flexural strength were assessed before and after the grinding procedure to determine the 'best test group' in Phase 1. The best abrasive agent was selected for Phase 2 of the study. The specimens in Phase 2 underwent grinding with the best abrasive agent selected. Following the grinding, the specimens were then polished using commercially available diamond polishing paste, a porcelain polishing kit, and an indigenously developed low-temperature sintered zirconia slurry. The physical and mechanical properties were again assessed. Results were analyzed using one-way ANOVA test. Specimens were observed under scanning electron microscopy (SEM) and X-ray diffraction (XRD) for their microstructure and crystalline phases, respectively. Grinding with diamond burs did not weaken zirconia (p > 0.05) but produced rougher surfaces than the control group (p < 0.05). Tungsten carbide burs did not significantly roughen the zirconia surface. However, specimens ground by tungsten carbide burs had a significantly reduced mean flexural strength (p < 0.05) and SEM revealed fine surface cracks. Phase transformation was not detected by XRD. Polishing with commercially available polishing agents, however, restored the surface roughness levels to the control group. Dental monolithic zirconia ground with tungsten carbide burs had a significantly reduced flexural strength and a smooth but defective surface. However, grinding with diamond burs roughened the zirconia surface. These defects may be reduced by polishing with commercially available polishing agents. The use of tungsten carbide burs for grinding dental zirconia should not be advocated. Grinding with diamond abrasives does not weaken zirconia but requires further polishing with commercially available polishing agents.

Comparative evaluation of implant stability quotient trends, crestal bone loss and survival of photofunctionalised and untreated dental implants: A split-mouth randomised controlled clinical trial.

PURPOSE: To evaluate the crestal bone loss and implant stability quotient trends of photofunctionalised versus untreated implants. MATERIALS AND METHODS: A total of 34 patients (age 46.94 ± 12.03 years) with bilateral single missing teeth in the same arch were enrolled in this study. Each patient received an untreated implant on one side (control group, n = 34) and a photofunctionalised implant on the contralateral side (test group, n = 34). Crestal bone loss was assessed at the time of crown insertion and 1 year later. The osseointegration speed index was evaluated for both the control and test group. An independent t test was used for intergroup comparisons of crestal bone loss and osseointegration speed index. Bivariate analysis was performed for the confounding variables. RESULTS: The test group showed a statistically significantly higher osseointegration speed index (3.07) as compared to the control group (1.29) (P < 0.01). Statistically significantly higher crestal bone loss was observed in the control group (-0.57 ± 0.41 mm) as compared to the test group (-0.27 ± 0.35 mm) (P < 0.01). The difference between mean Plaque Index and Bleeding Index in the control (0.74/0.38) and test group (0.73/0.35) was statistically insignificant (P > 0.05). A negative correlation (r = -0.272) was noted between implant diameter and crestal bone loss. A positive correlation (r = 0.402) was observed between implant length and osseointegration speed index. CONCLUSION: Implants with photofunctionalised surfaces reduce overall healing time and crestal bone loss. Photofunctionalisation is an effective aid for chairside conditioning of implant surfaces to achieve faster osseointegration with good crestal bone stability.

Ultrasound and CBCT analysis of blood flow and dimensions of the lingual vascular canal: A case control study.

OBJECTIVE: To assess the correlation between the diameter of the mandibular lingual vascular canal (MLVC) as determined on CBCT examination to blood flow and arterial diameter as determined by ultrasound Doppler analysis (USG) in dentate and edentulous patients. METHODS: 20 subjects were equally distributed into two groups based on the status of their dentition. Group 1 included dentate subjects (DE) and Group 2 included edentulous subjects (ED).The subjects from both the groups underwent CBCT scan for the assesement of the diameter of the MLVC.Similarly, USG was done to assess the diameter of the sublingual artery anastomosis and blood flow in the anterior mandible. Data was analysed using Karl Pearson's Correlation coefficient test and Student's unpaired 't' test. RESULTS: Irrespective of the status of the dentition and age, a positive correlation was noted between the diameter of foramen on CBCT examination and the diameter of anastomosing artery as studied by the USG (r â€‹= â€‹0.290).Similarly, a positive correlation was observed between the diameter of foramen on CBCT and the volume of blood entering the mandible (r â€‹= â€‹0.447).A positive correlation (r â€‹= â€‹0.138) was observed between the diameter of the anastomosing artery and the volume of blood entering the mandible. CONCLUSION: The anterior mandible has a rich vascular supply independent of age and status of the dentition.The dimensions and location of MVLC could be assessed on a CBCT prior to implant placement so that the operating surgeon has an idea about the vascularity of the region. Further studies with higher sample size should be undertaken to confirm these findings.

Effect of crown-to-implant ratio on the marginal bone level changes and implant survival - A systematic review and meta-analysis.

The purpose of the systematic review and meta-analysis was to analyze the existing evidence regarding the effect of crown-to-implant ratio (CIR) on the peri-implant crestal bone level change and implant survival. Randomized controlled clinical trials, prospective as well as retrospective studies with a minimum follow-up period of 12 months and 10 patients per group were included for this systematic review. Statistical analysis was performed to determine CIR effects on the peri-implant marginal bone level changes and implant survival. A total of 28 articles (14 prospective studies and 14 retrospective studies) from a database of 201 articles, with 2097 patients and 4350 implants, were included. A mean CIR ranging from 0.6 to 2.44 was presented by the study groups. A weighted mean implant loss of 0.19% per year and peri-implant marginal bone level change of 0.63 mm ± 0.55 over 46.8 ± 5.2 months was calculated from the included studies. The peri-implant marginal bone level change (p = 0.155) and the rate of implant loss (p = 0.245) showed a statistically insignificant difference between implant restorations of a high (>1.5:1) and low (<1.5:1) CIR. Within its limitations, this review concludes that a high (>1.5:1) or a low (<1.5:1) CIR does not significantly affect the peri-implant marginal bone level change and implant survival rate. However, until further evidence becomes available, extrapolation to long term clinical success cannot be ascertained.

Prosthetic outcomes and clinical performance of CAD-CAM monolithic zirconia versus porcelain-fused-to-metal implant crowns in the molar region: 1-year results of a RCT.

OBJECTIVE: To investigate the clinical performance of monolithic zirconia implant crowns as compared to porcelain-fused-to-metal (PFM) implant crowns. MATERIALS AND METHODS: Seventy-six healthy patients received reduced diameter implants in the molar region. Following random allocation, either a monolithic zirconia crown (Mono-ZrO2 ) or a (PFM) was inserted. Crown and implant survival rates, modified USPHS criteria, clinical measurements, and interproximal marginal bone level (MBL) were assessed at crown delivery (baseline, BL) and at the 1-year follow-up (1y-FU). Data were analyzed descriptively. Fisher's exact test and Wilcoxon rank sum test were applied for statistical analysis. The level of statistical significance was set at p < .05. RESULTS: Thirty-nine Mono-ZrO2 and 37 PFM crowns were delivered. At the 1y-FU, one crown in each group was lost due to loss of the implant. Technical complications occurred in the PFM group and were limited to four minor ceramic chippings resulting in a total technical complication rate of 11.1% (p = .024). Anatomical form and color match compared to the adjacent dentition were rated significantly inferior for the Mono-ZrO2 crowns. Patient satisfaction was high in both groups at BL (34 Mono-ZrO2 34 PFM) and at 1y-FU (36 Mono-ZrO2 31 PFM). No significant differences between the groups were detected with respect to the change in MBL and to the soft tissue parameters. CONCLUSIONS: Monolithic zirconia crowns are a similarly successful alternative option to PFM crowns for restoring single implants in the posterior area.

Anatomic variations of the osteomeatal complex and its relationship to patency of the maxillary ostium: A retrospective evaluation of cone-beam computed tomography and its implications for sinus augmentation.

AIM: The aim of this study is to determine the incidence of obliterated osteomeatal complex (OMC) due to the presence of anatomic variants. SETTINGS AND DESIGN: Retrospective Study. MATERIALS AND METHODS: In this retrospective study, a total of 71 patients, 34 males and 37 females, aged 35-65 years were included in the study. Cone beam computed tomography (CBCT) scans of patients were assessed to identify the status of the OMC in the presence of anatomic variants and their incidence was recorded. The radiological assessment of the anatomical variants was made by viewing the coronal sections of the scans. The variants observed were deviated nasal septum, uncinate process), agger nasi, Haller cells, middle turbinate variants, enlarged bulla, accessory ostium, and maxillary sinus abnormalities). Ostium patency was evaluated in the coronal section of each sinus and classified as "patent" or "obstructed." The most common variants observed were then correlated with the patency of the ostium. STATISTICAL ANALYSIS USED: Chi square test was performed to assess the association between the anatomic variants and the patency of the OMC. RESULTS: In the present study, the incidence of an obliterated OMC due to the presence of anatomic variants was 73.2%. The four most common variants associated with the possibility of an obliterated OMC were the deviated nasal septum (76.2%), middle turbinate (86.4%), enlarged bulla (77.8%), and sinus cavity variants (80.0%). A statistically significant association was noted between middle turbinate variants and Haller cells and the patency of the OMC. CONCLUSION: Thorough pretreatment CBCT evaluation should be performed to assess the presence of anatomic variants and thereby, the patency of the ostium before sinus floor elevation procedures. The pre and postsurgical treatment plans and regimes can be modified according to anticipated postsurgical sequelae, thereby avoiding postsurgical complications and enhancing the success of the graft procedure.

Evaluation of mechanical and adhesion properties of glass ionomer cement incorporating nano-sized hydroxyapatite particles.

Glass ionomer cement is a widely used luting agent for indirect restorations but presents inferior mechanical properties compared to resin cement due to its low elastic modulus. This study evaluated the mechanical and adhesion properties of glass ionomer luting cements reinforced with nano-sized hydroxyapatite particles (HA). The nano-sized HA particles were synthesized using the co-precipitation technique and the resulting precipitate was characterized using X-ray diffraction analysis (XRD), field emission scanning electron (FESEM) and transmission electron microscopy (TEM). HA particles were incorporated into the glass powder (FUJI I, GC) and the luting agent was manipulated in a liquid to powder ratio of 3:1 into 6% by weight after determining the best ratio. The flexural strength of the luting agent and shear bond strength of dentin were analyzed and compared to other luting agents namely, (a) glass ionomer (FUJI I), (b) resin-modified glass ionomer (RelyX Luting Plus) and (c) adhesive resin cement (RelyX U200). Failure types after debonding from dentin were evaluated under SEM. Flexural strength and bond strength data were analyzed using one-way ANOVA and Tukey's tests (alpha = 0.001). Addition of 6 w % HA particles in the range of 80-150 nm enhanced the flexural strength (30.97 ± 5.9 versus 11.65 ± 5.63) and shear bond strength (0.97 ± 0.41 versus 0.39 ± 0.16) of a conventional glass ionomer luting agent significantly compared to the non-reinforced ones when manipulated at a liquid to powder ratio of 3:1 (P < 0.001). While conventional glass ionomer, HA-reinforced glass ionomer and resin-modified glass ionomer specimens showed exclusively mixed type of failures, adhesive resin cement showed cohesive failures within the resin cement. Increased mechanical and adhesion potential of the experimental glass ionomer luting agent after incorporation of HA particles could expand the scope of application of this cement.

Correction To: Evaluation of mechanical and adhesion properties of glass ionomer cement incorporating nano-sized hydroxyapatite particles.

In the original publication of the article, the family name of the author.

Replicating a discolored tooth preparation: A technique for effective laboratory communication.

Fabricating a ceramic restoration for a discolored anterior tooth presents a clinical challenge. The dental technician is often hampered by being unaware of the shade of the discolored tooth preparation, which influences the color of the overlying ceramic restoration. A definitive cast that replicates the shade of the prepared tooth helps the ceramist to fabricate a restoration that masks the discoloration appropriately and still achieves the desired optical properties. This report demonstrates the use of a technique of recording and communicating the shade of a prepared tooth to the dental laboratory technician.

Does Graft Particle Type and Size Affect Ridge Dimensional Changes After Alveolar Ridge Split Procedure?

PURPOSE: The absence of an adequate volume of bone at implant sites requires augmentation procedures before the placement of implants. The aim of the present study was to assess the ridge width gain with the use of allografts and biphasic ß-tricalcium phosphate with hydroxyapatite (alloplast) in ridge split procedures, when each were used in small (0.25 to 1 mm) and large (1 to 2 mm) particle sizes. PATIENTS AND METHODS: A randomized controlled trial of 23 subjects with severe atrophy of the mandible in the horizontal dimension was conducted in a private institute. The patients underwent placement of 49 dental implants after a staged ridge split procedure. The patients were randomly allocated to alloplast and allograft groups (predictor variable). In each group, the patients were randomly assigned to either small graft particle or large graft particle size (predictor variable). The gain in ridge width (outcome variable) was assessed before implant placement. A 2-way analysis of variance test and the Student unpaired t test were used for evaluation of the ridge width gain between the allograft and alloplast groups (predictor variable). Differences were considered significant if P values were < .05. RESULTS: The sample included 23 patients (14 men and 9 women). The patients were randomly allocated to the alloplast (n = 11) or allograft (n = 12) group before the ridge split procedure. In each group, they were assigned to a small graft particle or large graft particle size (alloplast group, small particle in 5 and large particle size in 6 patients; allograft group, small particle in 6 and large particle size in 6). A statistically significant difference was observed between the 2 graft types. The average ridge width gain was significantly greater in the alloplast group (large, 4.40 ± 0.24 mm; small, 3.52 ± 0.59 mm) than in the allograft group (large, 3.82 ± 0.19 mm; small, 2.57 ± 0.16 mm). For both graft types (alloplast and allograft), the large particle size graft resulted in a greater ridge width gain compared with the small particle size graft (P < .05). CONCLUSIONS: Within the limitations of the present study, we suggest the use of large particle alloplast as the graft material of choice for staged ridge split procedures in the posterior mandible.

Effect of newly developed pigments and ultraviolet absorbers on the color change of pigmented silicone elastomer.

AIM AND OBJECTIVE: The aim and objective of the study is to evaluate effect of ultraviolet (UV) stabilizer (UV absorber Chimassorb 81) on color change of pigmented silicone elastomer when commercially available (red and yellow), and newly developed pigments (sicotrans red and sicopal brown) were used. MATERIALS AND METHODS: Two commercially available pigments - red (P112 Brilliant Red) and yellow (P106 Yellow) and two newly developed pigments - sicotrans red and sicopal brown were studied. In total eight groups made up of nine samples each were fabricated using elastomer with the combinations of the above pigments and UV stabilizer (Chimassorb 81). Groups 1, 3, 5, and 7 contain elastomer in combination with sicotrans red, sicopal brown, yellow and red pigments, respectively. Similarly, groups 2, 4, 6, and 8 along with elastomer and pigments (sicotrans sed, sicopal brown, yellow and red, respectively) contain the UV stabilizer (Chimassorb 81). Samples were subjected to aging in an accelerated weathering chamber (Weather-Ometer). Color values CIE (Commission Internationale d'Eclairage) L*, a*, and b * were measured at baseline and after 1000 h of weathering. Change in color (Delta E) was calculated. RESULTS: All groups showed a significant color change at 1000 h. Groups 1, 2, 3, and 4 showed a statistically significant less change in both colors (sico trans red and sicopal brown) compared to groups 5,6,7, and 8 (commercial pigments-Red and Yellow). Overall, the change in the color in groups with the UV stabilizer (Chimassorb) was less when compared to the groups where the stabilizer was not used. CONCLUSION: The newly developed pigment led to increased color stability as compared to commercially available pigments. Addition of UV stabilizer, Chimassorb led to a further reduction in color change of the pigmented elastomer.

Comparison of photographic and conventional methods for tooth shade selection: A clinical evaluation.

AIM: This study aimed to compare three different methods used for shade selection, i.e., visual method, spectrophotometer, and digital photography method. MATERIALS AND METHODS: Fifty participants were selected from the Out Patient Department of Prosthodontics. Presence of the maxillary right central incisor with no history of any restorative or endodontic procedures was the primary inclusion criterion. The shade of the right maxillary central incisor was determined using all the three shade selection procedures, namely, visual, spectrophotometric, and digital photography method for all the selected participants. The shades obtained in the visual method using a shade guide were noted down for further comparisons. The spectrophotometer reported the L*, a*, and b* values along with the actual shade whereas the digital photography method reported only the L*, a*, and b* values. The agreement between the readings obtained by the three different methods was compared and subjected to appropriate statistical analysis. RESULTS: The results showed that when the three methods studied were compared, there was a statistically significant proportion of agreement between spectrophotometric and visual method (P < 0.01) with higher proportion of "yes" (agreement) and between the spectrophotometric and digital photography method (P < 0.01) with higher proportion of "yes" (agreement). Coefficient of agreement (using Kappa coefficient) between spectrophotometric and visual shades revealed a fair agreement. The mean ΔE was 1.69. There was a statistically significant difference between the proportion of ΔE more than and <2, between spectrophotometric and digital photography methods (P < 0.01) with higher proportion of <2 ΔE. Furthermore, percentage of agreement between shades obtained by the visual and spectrophotometric method showed maximum agreement with A1 shade. CONCLUSION: It was concluded that the digital photography method emerged as a reliable method for shade selection in a clinical setup.