Prevalence and risk of peri-implant diseases based on the type of prosthetic restoration: A retrospective study after 17 to 23 years.

STATEMENT OF PROBLEM: Information on the epidemiology and etiopathology of peri-implant diseases in reference to prostheses is sparse. PURPOSE: The purpose of this retrospective clinical study was to analyze the prevalence and risk of peri-implant diseases based on the type of prosthesis. MATERIAL AND METHODS: A total of 274 implants in 106 patients were evaluated by clinical and radiological examination. Peri-implant mucositis was defined by bleeding on probing, whereas peri-implantitis was defined by additional bone loss ≥1.5 mm since seating of the definitive prosthesis. Prosthetic design and anamnestic risk factors were assessed in a regression analysis, whereas clinical and radiological differences between the prosthesis groups were compared by the Pearson chi-squared test (α=.05 for all procedures). RESULTS: The median observation period was 18 years. Seventy-two implants were restored with single crowns, 138 implants with fixed partial dentures, and 64 implants with removable prostheses. Peri-implant mucositis was diagnosed more often in implants supporting fixed partial dentures (42.8%), whereas peri-implantitis was found more frequently in implants supporting removable prostheses (31.3%) (overall distribution pattern: P<.001). The type of prosthetic restoration was confirmed to be an independent prognostic risk factor regarding peri-implant diseases (P=.005). Additionally, increased bone loss was found with implant-supported removable prostheses, regardless of peri-implantitis (P<.001). CONCLUSIONS: The type of prosthetic restoration was identified as an independent risk factor for the development of peri-implant diseases. Particularly, implants supporting double crown-retained removable prostheses might be at risk.

Patterns of care, toxicity and outcome in the treatment of salivary gland carcinomas: long-term experience from a tertiary cancer center.

BACKGROUND: Salivary gland carcinomas (SGC) cover a heterogeneous group of malignancies with a lack of data of high-level evidence. METHODS: Clinical data of 127 patients treated for SGC at a university cancer center between 2002 and 2017 were analyzed retrospectively. The association of clinicopathological characteristics, treatment modalities, adverse events, and outcome was assessed. RESULTS: Patients received surgery (n = 65), surgery followed by (chemo-)radiotherapy (n = 56), or primary (chemo-)radiotherapy (n = 6). Injury to the cranial nerves or their branches was the most frequent surgical complication affecting 40 patients (33.1%). Ten year overall and progression-free survival rates were 73.2% and 65.4%, respectively. Parotid tumor site, advanced tumor, and positive nodal stage remained independent negative prognostic factors for overall survival, loco-regional and distant tumor control in multivariate analysis. CONCLUSIONS: Optimizing treatment strategies for SGC, depending on distinct clinicopathological factors, remains challenging due to the low incidence rates of the disease.

Prognostic impact of CD8-positive tumour-infiltrating lymphocytes and PD-L1 expression in salivary gland cancer.

OBJECTIVES: Aim of the study was to evaluate the prognostic impact of CD8-positive (CD8+) tumour-infiltrating lymphocytes (TILs) and PD-L1 expression on the outcome of patients with malignant salivary gland neoplasms. MATERIALS AND METHODS: Formalin-fixed, paraffin-embedded tissue samples and clinicopathological data from patients treated for salivary gland carcinoma in a head and neck cancer centre were retrospectively retrieved. Immunohistochemical staining was applied on sections of 84 specimens of 12 different histological subtypes. Both CD8 and PD-L1 expression were rated by semi-automated cell counts by a digital image analysis programme. Survival analyses were performed by the log-rank test on the univariate level, and the Cox model was applied on the multivariate level. Associations between immunological markers and clinicopathological variables were estimated by the Pearson chi-squared test. Additionally, PD-1 was estimated as an exhaustion marker of CD8+ TILs. RESULTS: Patients exceeding a tumour proportion score ≥5% regarding PD-L1 expression demonstrated a significantly decreased survival, as did individuals with an overall high CD8+ cell density. Particularly, high CD8+ cell counts in the invasive front of the respective tumour tissue significantly coincided with a poor outcome. Also, high numbers of CD8+ TILs significantly matched with a high quantity of PD-1+ TILs. CONCLUSION: CD8+ TILs abundance in the peritumoural microenvironment correlates with impaired outcome of patients with salivary gland carcinoma. The simultaneous negative prognostic impact of PD-L1 expression and presence of PD-1+ TILs advocates an immune checkpoint-controlled mechanism of CD8+ TILs exhaustion for these tumours and paves the way for future treatment strategies.

Incidence and prevalence of peri-implantitis and peri-implant mucositis 17 to 23 (18.9) years postimplant placement.

PURPOSE: To evaluate the prevalence of peri-implantitis (PI) and peri-implant mucositis (PM) in a long-term follow-up with comparison among different PI and PM definitions, and to report on the incidence of PI. MATERIALS AND METHODS: In a retrospective clinical study five different PI and PM definitions were applied onto a population with 274 implants 17 to 23 years postimplant placement. Recommendations by the Eighth European Workshop on Periodontology (EWOP) were used as base reference. Clinical and radiological measurements were considered. Risk factors were evaluated in a regression analysis. RESULTS: After an average observation period of 18.9 years, 40.1% of the implants were diagnosed with PM and 15.0% with PI (Eighth EWOP). PI incidence reached 7.9% on implant level and 13.2% on patient level. Implants diagnosed with PI and progressive bone loss displayed exceptionally vertical bone defect configuration (BDC). Diabetes mellitus, smoking, regular maintenance, or a former periodontal infection did not show significant influence on the prevalence of peri-implant diseases. Patients with bruxism displayed significantly less PM and PI. CONCLUSIONS: Vertical BDC seems to correspond with active PI, wherefore we estimate such a defining factor of importance. Diagnosis of PM and evaluation of probing pocket depths might be only of descriptive interest as they could lead to false-positive results.