Comparison of the effects of cement removal from zirconia and titanium abutments: An in vitro study.

STATEMENT OF PROBLEM: Excess cement around dental implants is a significant cause of peri-implant inflammation. Research has focused on approaches to cement removal, the type of cement used, and the different instruments used for cement removal with titanium abutments. However, data comparing zirconia with titanium abutments are lacking. PURPOSE: The purpose of this in vitro study was to compare the effectiveness of excess cement removal from zirconia and titanium custom abutments using an explorer and to compare the effects of cement removal on the abutment surfaces. MATERIAL AND METHODS: Implant analogs were placed in a cast in the position of the 2 maxillary central incisors. After creating similar emergence profiles for both the implant abutments, 18 zirconia and titanium custom abutments were fabricated with 1-mm subgingival finish lines on the facial and interproximal areas and an equigingival finish line on the palatal side. The crowns were cemented with zinc oxide-eugenol cement, and a steel explorer was used to remove the excess cement. All abutments were analyzed under a scanning electron microscope for cement remnants and scratches. RESULTS: The mean surface area of cement remnants on the zirconia abutments was 778 ±113 µm2, and for titanium abutments, it was 1123 ±252 µm2, which in terms of the mean percentage area was 3.27% of the total surface area of zirconia and 4.71% of titanium abutments. Only a few abutments from each group showed scratches, and no deep scratches or gouges were observed. CONCLUSIONS: Zirconia and titanium abutments had statistically similar cement remnants. Scratches were observed on only a few specimens.

Digital technology for performing a nasopalatine and greater palatine nerve block with a modified implant surgical guide: A technique article.

This article describes a computer-aided design and computer-aided manufacturing (CAD-CAM) technique to perform a precise nerve block of the nasopalatine and greater palatine nerves by using an implant surgical guide. The technique uses additional guide anchor pins planned and positioned for specific anatomic landmarks during guided implant surgical guide planning. A relief modification virtually designed on the intaglio surface of the surgical guide allows for palatal soft tissue distension following administration of local anesthetic. This information is then transferred to the guide manufacturer to order the modified guided implant surgical guide. The purpose of this procedure is to provide precise delivery of local anesthetic and to prevent any discrepancy in surgical guide seating following injection.

Predictable prosthetic space maintenance during staged complete-mouth rehabilitation.

Staged complete-mouth rehabilitation to accommodate a patient's financial constraints during the course of treatment is presented. Clear acrylic resin added to the anterior cameo surface of the maxillary fixed complete denture (FCD) served as a space maintainer. The restoration of the maxillary FCD addressed the patient's chief complaint. By adding the space maintainer, supraeruption of mandibular anterior teeth and encroachment of the prosthetic space, which could have resulted in additional treatment, was avoided. During the second stage of the complete-mouth rehabilitation, zirconia restorations were used to restore the mandibular arch to the maxillary FCD after straightforward removal of the space maintainer. This allowed a smooth transition after a delay in treatment without having to modify the previous treatment.

Comparative Evaluation of the Effect of Laser Etching on the Shear Bond Strength of Crowns Cemented with Two Different Luting Agents: An In Vitro Study.

PURPOSE: The aim of this study was to compare the shear bond strength of crowns cemented on natural teeth after surface treatment of the enamel with an erbium-doped yttrium aluminum garnet (Er:YAG) laser. MATERIALS AND METHODS: Crown preparation was done for 40 full-metal crowns, and wax patterns with loops were cast in a cobalt-chromium alloy. The Er:YAG laser was used for surface treatment of some teeth, and teeth without surface treatment acted as the control. Glass-ionomer and self-adhesive resin luting cements were used for cementation. Shear bond strength was tested using a universal testing machine, and statistical analysis was done using paired t test. Scanning electron microscopy analysis was also carried out to study alterations of the enamel and dentin surfaces. RESULTS: Significant increase in shear strength was noted after laser etching the teeth with Er:YAG laser for both types of cement (P < .0001). CONCLUSION: The results showed that surface treatment using an Er:YAG laser resulted in significant increase in retention of crowns.

Comparison of maxillary anterior tooth width and facial dimensions of 3 ethnicities.

STATEMENT OF PROBLEM: As the cosmetic demands of patients increase, determining the appropriate dimensions of the maxillary anterior teeth has become increasingly relevant. The relationship between facial measurements and tooth size provide guidance for maxillary anterior tooth size selection. However, most publications on this topic have focused on the white population, and more data for tooth sizes and their proportions in other ethnicities are needed. PURPOSE: The purpose of this observational study was to investigate the relationship between the mesiodistal dimensions of the 6 maxillary anterior teeth and the bizygomatic width, interpupillary distance, intercanthal distance, interalar width, and intercommissural width of individuals of Asian, African-American, and white ethnicities. MATERIAL AND METHODS: Standardized digital images of 360 participants (120 Asian, 120 African-American, and 120 white) were used to measure facial segments. Individual dimensions of the 6 maxillary anterior teeth were measured using stone casts with digital sliding caliper. The combined width of the 6 maxillary anterior teeth on a straight line corresponded to the sum of the anterior tooth width. The means and standard deviations from descriptive measurements were calculated and analyzed for face and maxillary anterior tooth ratios and correlations. Statistical analysis was done using the Kruskal-Wallis procedure to compare facial and tooth parameters among the 3 ethnicities. Appropriate post hoc comparisons that adjusted for multiple testing were conducted when warranted (α=.05). The Spearman rho correlation, a nonparametric correlate of the Pearson correlation, was used to associate the facial and tooth parameters within the strata of sex and ethnicity. RESULTS: No consistent ratios were found among the examined facial dimensions and the mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities, except for the central incisor width-to-bizygomatic width ratio. No correlations were found between the facial dimensions and mesiodistal dimensions of the 6 maxillary anterior teeth among the 3 ethnicities except in Asian women. For Asian women, the intercommissural width correlated with the width of the central incisor (P=.001), the width of 2 central incisors (P=.001), the width of 4 incisors (P=.003), and the width of 6 maxillary anterior teeth (P=.005). CONCLUSIONS: No facial proportions by which the exact width of maxillary anterior teeth could be predicted were found in Asian, African-American, or white populations.