Cross-sectional analysis comparing prefabricated titanium to individualized hybrid zirconia abutments for cemented zirconia based fixed dental prostheses: a critical concept assessment.

PURPOSE: Despite the differences in material properties and shapes among the different types of prefabricated titanium (pTiA) and individualized hybrid zirconia abutments (ihZiA), the biological and clinical relevance of materials and construction features remains vague. Yet, individualized ihZiA are increasingly implemented into daily routine aiming to satisfy rising expectations. The objective was to compare these two types of abutments in fixed dental prostheses (FDP). METHODS: This cross-sectional study examined 462 implants in 102 patients comparing pTiA (52 patients) to ihZiA (50 patients) for FDP. These different treatment regimens were evaluated in terms of peri-implant health, radiographic bone loss, and oral-health related quality of life (OH-QoL) with special consideration of abutment type and superstructure design. RESULTS: ihZiA showed significantly different design features than prefabricated pTiA, but the annual bone loss in both groups did not. Visible titanium in the esthetic zone negatively impacted OHIP 14 scores. The combination of an emergence angle (EA) of < 30° and a concave emergence profile (EP) as well as gingiva thickness (p = 0.002) at the time of the prosthetic restoration significantly improved the annual peri-implant bone loss, independently of the abutment type. CONCLUSION: ihZiA showed comparable results to pTiA. To optimize the long-term outcome, not just material alone but generating adequate soft tissue thickness, minimizing the EA, and applying a concave EP seem to be the most relevant factors. To improve OH-QoL, particular attention must be paid to the esthetic zone.

Vestibuloplasty and its impact on the long-term survival and success of dental implants in irradiated and non-irradiated patients after head and neck tumor therapy: a retrospective study.

OBJECTIVES: This study aimed to evaluate the influence of vestibuloplasty on the clinical success and survival of dental implants in head and neck tumor patients. MATERIALS AND METHODS: A retrospective single-center study was conducted. All patients received surgical therapy of a tumor in the head or neck and underwent surgical therapy and, if necessary, radiotherapy/radiochemotherapy. Patients with compromised soft tissue conditions received vestibuloplasty using a split thickness skin graft and an implant-retained splint. Implant survival and success and the influence of vestibuloplasty, gender, radiotherapy, and localizations were evaluated. RESULTS: A total of 247 dental implants in 49 patients (18 women and 31 men; mean age of 63.6 years) were evaluated. During the observation period, 6 implants were lost. The cumulative survival rate was 99.1% after 1 year and 3 years and 93.1% after 5 years for patients without vestibuloplasty, compared to a survival and success rate of 100% after 5 years in patients with vestibuloplasty. Additionally, patients with vestibuloplasty showed significantly lower peri-implant bone resorption rates after 5 years (mesial: p = 0.003; distal: p = 0.001). CONCLUSION: This study demonstrates a high cumulative survival and success rate of dental implants after 5 years in head and neck tumor patients, irrespective of irradiation. Patients with vestibuloplasty showed a significantly higher rate of implant survival and significantly lower peri-implant bone resorption after 5 years. CLINICAL RELEVANCE: Vestibuloplasty should always be considered and applied if required by the anatomical situations to achieve high implant survival/success rates in head and neck tumor patients.

Gender- and age-related differences in the width of attached gingiva and clinical crown length in anterior teeth.

BACKGROUND: The anatomical features of the gingiva and the clinical crowns and their interrelation, especially in aesthetically and functionally demanding areas, are important in complex dental or implant-retained prosthetic rehabilitations. This observational cross-sectional study was designed to evaluate gender- and age-related differences in the width of attached gingiva (WAG), the clinical crown length (CCL), and their interrelation in the anterior teeth to determine the relationship between the pink and white aesthetics. METHODS: Eighty (54 females, 26 males) fully dentate Caucasian participants between the ages of 20 and 25 years and 36 probands (23 females, 13 males) between the ages of 45 and 55 years were included in the present study. The CCL of the maxillary and mandibular canines, as well as the central incisors of the maxilla and mandible, were determined with a dental sliding caliper measuring from the middle margin of the gingiva at its deepest point to the incisal edge. The clinical investigation of the WAG was performed by inserting a periodontal probe into the gingival sulcus in the middle of the buccal surface to firstly measure the probing pocket depth. The distance between the gingival margin and mucogingival junction (MGJ) was then measured with a Beerendonk sliding caliper in the middle of the labial curvature, and the clinical WAG was determined by subtraction of the measured probing depth. For the statistical analysis, the Mann-Whitney U test, the Wilcoxon-Test, the Spearman's rank correlation, and a two-factorial non-parametric analysis were used. RESULTS: There was no correlation between the CCL and the WAG in a healthy periodontium. Gender influenced the CCL, with men having significantly longer teeth than women in both maxilla (P ≤ 0.01) and mandible (P ≤ 0.05). Age did not influence the CCL significantly neither in the upper (P = 0.06) nor in the lower jaw (P = 0.33). Gender did not show to have a significant influence on the WAG of maxilla (P = 0.69) and mandible (P = 0.26). But differences in the WAG between young and old participants were observed in both upper (P ≤ 0.01) and lower jaw (P ≤ 0.05). CONCLUSION: The present observational study demonstrated that the mean values of cohorts with mixed age groups and genders should not be considered when attempting to determine the ideal relationships between the pink and white aesthetics since the statistical analyses showed significant differences between different age groups and genders.

Influence of implant-specific radiation doses on peri-implant hard and soft tissue: An observational pilot study.

OBJECTIVES: The aim of this study was to investigate the influence of real implant-bed-specific radiation doses on peri-implant tissue health in head and neck cancer (HNC) patients after radiotherapy. MATERIAL AND METHODS: Specific radiation doses in the area of 81 implants, in 15 irradiated HNC patients, were analyzed by matching data from the radiotherapy planning system with those of three-dimensional follow-up scans after implantation. Peri-implant bone resorption was measured radiographically after 1 and 3 years, and peri-implant tissue health was evaluated clinically. Individual parameters, such as age, gender, and localization, regarding the implant-specific radiation dose distribution were analyzed statistically. RESULTS: The mean implant-bed-specific radiation dose was high, with 45.95 Gy to the mandible and 29.02 Gy to the maxilla, but significantly lower than the mean total dose to the tumor bed. Peri-implant bone resorption correlated with local inflammation and plaque. After 1 year, women temporarily showed significantly more bone loss than men and implant-specific radiation dose had a significant impact on peri-implant bone loss after 3 years. CONCLUSIONS: The presented method is a feasible option to define precise implant-bed-specific radiation doses for research or treatment planning purposes. Implant-based dental restoration after radiotherapy is a relatively safe procedure, but a negative radiation dose-dependent long-term effect on peri-implant bone resorption calls for interdisciplinary cooperation between surgeons and radio-oncologists to define high-risk areas.

Age-Related Changes of the Orolabial Region in Caucasian Women: An Anthropometric Analysis.

PURPOSE: Anthropometric data can provide valuable support for the attending physician in planning surgical and nonsurgical esthetic procedures with regard to a patient's age. The purpose of the present study was to identify age-related orolabial changes in younger and older Caucasian women. MATERIALS AND METHODS: In the present cross-sectional study, anthropometric landmarks were identified using indirect anthropometry (2-dimensional photometry) in younger (≤35 yr) and older (≥50 yr) Caucasian women to analyze age-related parameters and proportions of the orolabial region, especially of the lower and upper lip vermilion areas. The Mann-Whitney U test was applied to compare the results between the younger and older populations. RESULTS: The study population consisted of 45 women. The cohort was divided into a younger population (24 participants; mean age, 27.4 yr) and an older population (21 participants; mean age, 58 yr) to evaluate age-related differences. Increases of upper lip height, cutaneous height of the upper lip, and cutaneous height of the lower lip were observed in older women. In contrast, the vermilion height of the lower lip decreased significantly with increasing age. CONCLUSION: These results show changes of the orolabial region occur in Caucasian women with increasing age. The statistically relevant decrease of the vermilion height of the lower lip should be given particular attention for (age-appropriate) diagnostic, esthetic, and prosthetic treatment planning.

Changes in Peri-Implant Bone Level and Effect of Potential Influential Factors on Dental Implants in Irradiated and Nonirradiated Patients Following Multimodal Therapy Due to Head and Neck Cancer: A Retrospective Study.

PURPOSE: The aim of the present study was to evaluate changes in the marginal bone level of dental implants in irradiated and nonirradiated patients and to identify possible influential factors. MATERIALS AND METHODS: Thirty-six patients with 194 implants were involved in the study (7 women and 29 men). The mean age of the patients was 65.8 years (39 to 90 yr). In all patients, a squamous cell carcinoma in the floor of the mouth involving the mandible or tongue was surgically removed. In 17 patients, adjuvant radiochemotherapy was completed a minimum of 6 months before implant placement. Mean crestal bone changes using standardized orthopantomographs were evaluated. The Spearman rank-order correlation coefficient and Mann-Whitney U test were used to determine correlations between bone crestal changes and age, gender, radiation therapy (yes vs no), augmentation (yes vs no), and type of superstructure. RESULTS: In total, 194 implants were placed (73 in the maxilla and 121 in the mandible). Mean amounts of peri-implant bone loss were 1 mm mesially and 0.9 mm distally after 1 year and 1.4 mm mesially and 1.3 mm distally after 3 years. During the observation period, 4 implants were lost. The overall success rate was 98.4% (maxilla, 100%; mandible, 96.7%). There was no relevant difference in changes in bone level according to age, gender, prosthetic superstructure, or augmentation procedure (yes vs no). Radiation therapy was found to have an effect on crestal bone loss. CONCLUSION: The present study showed a high success rate of dental implants after 3 years. Peri-implant crestal bone loss was comparable to that in patients without tumor. The mean amount of crestal bone change in irradiated patients was twice as high as that in nonirradiated patients.

Retrospective long-term analysis of bone level changes after horizontal alveolar crest reconstruction with autologous bone grafts harvested from the posterior region of the mandible.

PURPOSE: The goal of this study was to evaluate the long-term success of horizontal alveolar crest augmentation of the retromolar region of the mandible with particulated bone, as well as factors affecting subsequent peri-implant bone loss. METHODS: A total of 109 patients (68 female, 41 male) suffering from alveolar ridge deficiencies of the maxilla and mandible were included in this study. All patients were treated with particulated retromolar bone grafts from the mandible prior to the insertion of endosseous dental implants. Mesial and distal peri-implant crestal bone changes were assessed at six time points. Several parameters, including implant survival and the influence of age, gender, localisation of the implant, diameter, covering procedures, and time points of implant placement, were analysed to identify associations with bone level changes using the Mann-Whitney U-test, the Kruskal-Wallis test, and Spearman's rank-order correlation coefficient. RESULTS: A total of 164 dental implants were placed in the maxilla (n=97) and in the mandible (n=67). The mean observation period was 105.26±21.58 months after implantation. The overall survival rate was 97.6% after 10 years. Overall, peri-implant bone loss was highest during the first year, but decreased over time. The mean amount of bone loss after 10 years was 2.47 mm mesially and 2.50 mm distally. Bone loss was significantly influenced by implant type and primary stability. CONCLUSIONS: The use of particulated autologous retromolar bone grafts is a reliable technique for the horizontal reconstruction of local alveolar ridge deficiencies. Our results demonstrate that implants placed in augmented bone demonstrated similar bone level changes compared to implants inserted in non-augmented regions.