Clinical and radiographic performance of self-locking conical connection implants in the posterior mandible: Five-year results of a two-centre prospective study.

OBJECTIVE: This prospective study aims to assess the 5-year clinical performance of implants with internal conical connection and platform-switched abutments in the posterior mandible. MATERIAL AND METHODS: Healthy adults missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent implants. After a transmucosal healing period single crown restorations were cemented on platform-switched abutments. Changes in marginal bone levels were investigated in standardized periapical radiographs from surgery and loading (baseline) to 60-months post-loading. RESULTS: Twenty-four patients received 52 implants. Bone remodelling took place between surgery and loading (mean:-0.5, SD:±0.4 mm). From loading to 60 months, there was a mean bone change of 0.27 (SD:±0.47 mm) which stabilized 24 months after prosthesis delivery (mean:0.2, SD:±0.46 mm). 71.7% of all implants presented bone preservation at 60 months irrespective of the initial insertion depth. Two implants were lost after 5 years and the success rate was 95.1%. Patient enquiry revealed high satisfaction. CONCLUSION: Internal conical connection implants with platform-switched abutments presented a high success rate and preservation of marginal bone levels at the implant shoulder after 5 years of loading.

Peri-implant marginal bone loss reduction with platform-switching components: 5-Year post-loading results of an equivalence randomized clinical trial.

AIM: To compare the clinical performance and marginal bone levels of implants restored with platform-switching (PS) or platform-matching (PM) abutments. MATERIALS AND METHODS: Adult patients missing two or more adjacent teeth in the posterior mandible received 2-4 CAMLOG SCREW-LINE implants and were randomly allocated to the PM or PS group, receiving the corresponding prosthetic components from surgery onwards. Implants were conventionally loaded with single cemented crowns. Patients were followed annually for 5 years. Outcome measures were marginal bone level changes, implant survival, performance of the prosthetic components and clinical parameters plaque index, sulcus bleeding index and pocket probing depth. RESULTS: Thirty-three patients received 72 implants in the PM group, and thirty-five patients received 74 implants in the PS group. Sixty patients attended the final appointment, 31 had received PS components and 29 had received PM components with 65 and 63 implants, respectively. Global survival rate was 96.6% with no differences between groups (p = 0.647). After 5 years of functional loading, PS restored implants presented 0.23mm (95% CI: [0.03, 0.43], p = 0.025) lower marginal bone level changes. The two groups were declared non-equivalent. CONCLUSION: Patients requiring implant supported restorations in healed bounded or free end edentulous gaps of the mandible benefit from the use of PS components in terms of peri-implant marginal bone level maintenance, though it may not be clinically noticeable.

Immediate and flapless implant insertion and provisionalization using autogenous bone grafts in the esthetic zone: 5-year results.

OBJECTIVES: As the 2-year results for immediately inserted and provisionalized implants have been reported, it remained an open issue, whether the initially high success rates and the esthetic outcome remain stable for longer observation periods. Therefore, this prospective study examines the 5-year hard and soft tissue changes at implants placed in the anterior maxilla. MATERIAL AND METHODS: Meanwhile, 37 microthreaded implants were placed in 21 patients into extraction sockets with and without facial bone deficiencies by a flapless approach. Facial gaps and bony defects were grafted with autogenous bone chips. The implants were immediately provisionalized. The primary outcome parameters were the interproximal marginal bone level and the thickness of the facial bony wall. Implant success and Pink Esthetic Score (PES) were considered as secondary outcome parameters. RESULTS: Two patients with four implants withdrew from the study (dropouts), and the remaining 33 implants were still in function at a follow-up period of 68 months. Marginal bone height averaged 0.04 mm coronal to the implant shoulder. The thickness of the facial bony lamellae increased significantly between pre-op examination and 1-year follow-up (p = .002) and thereafter remained stable. Within 5 years of follow-up, 24 of 33 implants were clinically stable, free of signs and symptoms, and showed bone loss less than 1 mm. The mean PES ratings improved slightly from 10.7 pre-operatively to 11.7 at the last follow-up (p = .02). CONCLUSIONS: Interproximal marginal bone levels, survival rates, and esthetic results remain stable at the 5-year follow-up in implants used in an immediate insertion, reconstruction, and provisionalization concept. Facial marginal bone levels decreased slightly; however, this reduction did not affect the PES so far.

Biofunctionalization of porcine-derived collagen matrix using enamel matrix derivative and platelet-rich fibrin: influence on mature endothelial cell characteristics in vitro.

OBJECTIVES: The present study evaluated the effect of an enamel matrix derivative (EMD) and platelet-rich fibrin (PRF)-modified porcine-derived collagen matrix (PDCM) on human umbilical vein endothelial cells (HUVEC) in vitro. MATERIALS AND METHODS: PDCM (mucoderm®) was prepared to 6 mm (±0.1 mm) diameter discs. PDCM samples were incubated with either EMD, PRF, or control solutions for 100 min at 4 °C before the experiments. Cell-inducing properties of test materials on HUVEC cells were tested with cell proliferation assays (MTT, PrestoBlue®), a cytotoxicity assay (ToxiLight®), a Boyden chamber migration assay, and a cell attachment assay. Scanning electron microscopy (SEM) imaging was performed to determine the surface and the architecture of the modified matrices. RESULTS: Cell proliferation was elevated in the EMD and PRF groups compared with control (p each ≤0.046). PRF modification increased HUVEC migration ability by 8-fold compared with both control and EMD groups (p each <0.001). Both treatments significantly promoted the cell attachment of HUVEC to PDCM, as assessed by direct cell counts on the matrices (p each <0.001). CONCLUSIONS: HUVEC cell characteristics were overall improved by EMD- and PRF- modified PDCM. Adsorbed bioactive molecules to the PDCM surface may have contributed to a more preferable environment to surrounding cells. CLINICAL RELEVANCE: The results may give evidence that PDCM modification with EMD or PRF, respectively, might be a useful approach to improve clinical outcomes, to prevent inflammatory reactions and wound-healing disturbances, and to expand the clinical application area of PDCM.

Immediate provisionalization in the esthetic zone: 1-year interim results from a prospective single-cohort multicenter study evaluating 3.0-mm-diameter tapered implants.

OBJECTIVES: The aim of this interim analysis of a 5-year prospective multicenter study is to evaluate clinical and radiological performance of immediately provisionalized 3.0-mm-diameter tapered implants. MATERIALS AND METHODS: Patients needing implant rehabilitation of maxillary lateral incisors or mandibular lateral and central incisors were treated with 3.0-mm-diameter implants placed in extraction or healed sites and immediately provisionalized. Clinical and radiographic examinations were performed at implant insertion, 6 months thereafter, and are ongoing. Marginal bone levels and changes, complications, the papilla, plaque, and bleeding indices, and the pink esthetic score (PES) were evaluated at each follow-up visit. RESULTS: Of 112 enrolled patients, 77 patients (91 implants) met the inclusion criteria. Seventy-one patients with 82 implants completed the 1-year follow-up. Three implants failed yielding a CSR of 96.7%. All failures occurred within the first 3 months after implant insertion. Marginal bone level changes from insertion to 6 months was - 0.57 ± 1.30 mm (n = 75) and from insertion to 12 months - 0.25 ± 1.38 mm (n = 72). Fifteen non-serious complications were recorded. Papilla index score and PES improved at the 1-year follow-up. Plaque formation and bleeding-on-probing showed no statistically significant differences between the 6-month and the 1-year visit. CONCLUSIONS: This 1-year analysis demonstrated high survival, stable bone levels, and healthy soft tissue with 3.0-mm-diameter implants. CLINICAL IMPLICATIONS: Narrow diameter implants are a safe and predictable treatment option in patients with limited bone volume and/or limited interdental space and eligible for immediate loading protocols.

Effect of platform switching on crestal bone levels around implants in the posterior mandible: 3 years results from a multicentre randomized clinical trial.

OBJECTIVE: Evaluation of differences in the clinical performance and crestal bone levels between implants restored with single crowns with platform-matched or platform-switched abutments after 3 years. MATERIAL AND METHODS: The study enrolled adult patients missing two or more adjacent teeth in the posterior mandible with natural teeth mesial to the implant site. Randomization followed open-flap implant insertion and the corresponding matching or switching healing abutments placed at surgery. Conventional loading was made with cemented crowns. Clinical follow-up took place annually after loading up to 3 years. Bone level changes were measured in standardized radiographs as the variation in crestal bone from one evaluation to the next. RESULTS: Sixty-three patients with a total of 135 implants (66 platform matching, 69 platform switching) were analysed. From surgery to 36 months, mean bone loss was 0.28 ± 0.56 mm for the platform-switching group and 0.68 ± 0.64 mm for the platform-matching group. A statistically significant difference was found between groups (p = 0.002) with an estimate of 0.39 mm (0.15-0.64, 95% CI) in favour of platform switching. CONCLUSIONS: After 3 years, platform-switching restorations showed a significant effect in the preservation of marginal bone levels compared to platform-matching restorations.

Radiographic evaluation of conical tapered platform-switched implants in the posterior mandible: 1-year results of a two-center prospective study.

OBJECTIVE: Long-term success of dental implants depends on healthy peri-implant soft tissues and adequate bone levels. This prospective study aims to assess bone level changes around implants with internal conical connection and platform-switching abutments in the posterior mandible. MATERIAL AND METHODS: Adult patients missing at least two teeth in the posterior mandible and with a natural tooth mesial to the implant site received two or three adjacent internal conical connection implants. After a minimum transmucosal healing period of 8 weeks, single crown restorations were cemented over platform-switching abutments. Changes in marginal bone levels were measured in standardized periapical radiographs from surgery and loading (baseline) to 12 months post-loading. RESULTS: Twenty-four patients received 52 implants. Bone remodeling took place between surgery and loading (-0.53 ± 0.40 mm). From loading to 12 months, there was a mean bone gain of 0.12 ± 0.42 mm which occurred mainly in the first 6 months after prosthesis delivery (0.11 ± 0.36 mm) and stabilized afterward. A total of 71.7% of all implants presented bone preservation or gain. No implant was lost at 1 year and the success rate was 100%. Patient inquiry revealed high satisfaction. CONCLUSION: Internal conical connection implants with platform-switching abutments presented high success rate and enhancement or preservation of marginal bone levels after 1 year of loading.

Platform switch versus platform match in the posterior mandible ­ 1-year results of a multicentre randomized clinical trial.

OBJECTIVE: The purpose of this ongoing randomized study was to assess differences in bone level changes and success rates using implants supporting single crowns in the posterior mandible either with platform matched or platform switched abutments. MATERIAL AND METHODS: Patients aged 18 and above, missing at least two teeth in the posterior mandible and with a natural tooth mesial to the most proximal implant site were enrolled. Randomization followed implant placement. Definitive restorations were placed after a minimum transgingival healing period of 8 weeks. Changes in crestal bone level from surgery and loading (baseline) to 12-month post-loading were radiographically measured. Implant survival and success were determined. RESULTS: Sixty-eight patients received 74 implants in the platform switching group and 72 in the other one. The difference of mean marginal bone level change from surgery to 12 months was significant between groups (p < 0.004). Radiographical mean bone gain or no bone loss from loading was noted for 67.1% of the platform switching and 49.2% of the platform matching implants. Implant success rates were 97.3% and 100%, respectively. CONCLUSIONS: Within the same implant system the platform switching concept showed a positive effect on marginal bone levels when compared with restorations with platform matching.

Oral health-related quality of life of patients with oral lichen planus, oral leukoplakia, or oral squamous cell carcinoma.

PURPOSE: To compare oral health-related quality of life (OHRQoL) of patients with oral lichen planus (OLP), oral leukoplakia (OL), or oral squamous cell carcinoma (OSCC). MATERIALS AND METHODS: Seventy-three patients with OLP, 44 with OL, and 37 with OSCC participated in this prospective study. The German version of the 14-item Oral Health Impact Profile (OHIP-G 14) was used to measure OHRQoL. Descriptive statistics and multivariate analysis of clinical forms, age, gender, alcohol consumption, and smoking habits were evaluated. RESULTS: No association to cumulative OHIP-14 score (P = .086) among the 3 groups was found. However, patients with OLP showed a higher "physical pain" score and a lower "social disability" score (P = .026) than patients with OSCC, followed by patients with OL. Women with OLP had a lower OHRQoL than men. After differentiation of clinical forms of OLP (symptomatic vs asymptomatic), an impact on these patients' OHRQoL in the dimensions "physical pain" and "physical disability" was found. CONCLUSION: Patients with OLP or OSCC and high OHIP-G 14 scores reported physical pain, which emphasizes the need for physical therapy. For improved OHRQoL, patients with symptomatic forms of OLP would gain more from a treatment compared with those with asymptomatic forms. In contrast, patients with asymptomatic OLP or OL and thus with a minimal impact on their OHRQoL might be at risk of delayed consultation, diagnosis, and treatment of their condition.

ΔNp63 expression in four carcinoma cell lines and the effect on radioresistance--a siRNA knockdown model.

OBJECTIVES: This study investigated the expression of ΔNp63α in carcinoma cell lines of the upper aerodigestive tract and their potential influence on radioresistance using a small interfering RNA (siRNA) knockdown approach. MATERIALS AND METHODS: Four carcinoma cell lines were investigated for the expression of the ΔNp63 isoform by quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) (0, 24, 48 h) with and without single dose irradiation of 6 Gy. Furthermore, all cell lines were transfected with siRNA against the ΔNp63α isoform over 24 h. Knockdown effectiveness was controlled by qRT-PCR and Western blot. Apoptotic events were evaluated by terminal transferase dUTP nick end labeling (TUNEL) assay and cross-checked by a test for cell viability (WST-1, Roche) over 48 h. RESULTS: All cell lines presented varying expression of the ΔNp63α isoform with and without irradiation. A sufficient knockdown rate was established by siRNA transfection. Knockdown of the ΔNp63 isoform showed an effect on radiation sensitivity proven by an increase of apoptotic events detectable by immunofluorescence (TUNEL assay) and likewise a significant reduction of formazan production (WST-1 test) in three cell lines. CONCLUSIONS: We found overexpression of ΔNp63α with and without irradiation in three cell lines, and the knockdown of ΔNp63α led to increased apoptotic events and fewer viable cells. Thus, the overexpression of ΔNp63α might protect carcinoma cells against irradiation effects. CLINICAL RELEVANCE: The present work supports the hypothesis that protein 63 might serve as a negative predictor for irradiation response and survival in a clinical setting and may be a target for future therapeutic strategies.

Oral squamous cell carcinoma in the vicinity of dental implants.

OBJECTIVES: The study at hand presents a cohort of patients treated for carcinomas in the vicinity of dental implants for identification of potential risk factors. MATERIALS AND METHODS: The retrospective analysis covers patients treated for peri-implant carcinoma at our department between 1995 and 2011. An additional literature search focused likewise on peri-implant carcinomas. Obtained articles were screened for relevant risk factors and discussed in relation to our patient cohort. RESULTS: Fifteen patients were treated for peri-implant carcinoma. Six reported ongoing alcohol/tobacco consumption. Nine had a previously reported carcinoma of whom six had received radiotherapy after surgery. Time from implant placement until carcinoma diagnosis was 53.4 months on average. The literature search revealed 25 patients with peri-implant carcinoma and one with a sarcoma. Eight patients reported alcohol/tobacco consumption. Most patients exhibited risk factors for possible malignant transformation: previous carcinoma (n = 12), lichen (n = 4), irradiation (n = 3), and leukoplakia (n = 3). The average time until diagnosis was 51.6 months. CONCLUSIONS: Smoking, alcohol consumption, and the history of previous carcinoma characterize patients at risk for a peri-implant carcinoma. A balanced gender ratio might point at a higher risk for woman and additional risk factors promoting carcinogenesis apart from tobacco and alcohol consumption, a novel finding that has to be proven by larger patient counts. CLINICAL RELEVANCE: The incidence of carcinomas next to dental implants is low but may attain clinical relevance with raising implant figures worldwide. Patients at risk potentially profit from individualized recall intervals and careful evaluation.

Adjuvant Radiotherapy in Patients with Squamous Cell Carcinoma of the Oral Cavity or Oropharynx and Solitary Ipsilateral Lymph Node Metastasis (pN1)-A Prospective Multicentric Cohort Study.

(1) Background: Evaluation of impact of adjuvant radiation therapy (RT) in patients with oral squamous cell carcinoma of the oral cavity/oropharynx (OSCC) of up to 4 cm (pT1/pT2) and solitary ipsilateral lymph node metastasis (pN1). A non-irradiated group with clinical follow-up was chosen for control, and survival and quality of life (QL) were compared; (2) Methods: This prospective multicentric comprehensive cohort study included patients with resected OSCC (pT1/pT2, pN1, and cM0) who were allocated into adjuvant radiation therapy (RT) or observation. The primary endpoint was overall survival. Secondary endpoints were progression-free survival and QL after surgery; (3) Results: Out of 27 centers, 209 patients were enrolled with a median follow-up of 3.4 years. An amount of 137 patients were in the observation arm, and 72 received adjuvant irradiation. Overall survival did not differ between groups (hazard ratio (HR) 0.98 [0.55-1.73], p = 0.94). There were fewer neck metastases (HR 0.34 [0.15-0.77]; p = 0.01), as well as fewer local recurrences (HR 0.41 [0.19-0.89]; p = 0.02) under adjuvant RT. For QL, irradiated patients showed higher values for the symptom scale pain after 0.5, two, and three years (all p < 0.05). After six months and three years, irradiated patients reported higher symptom burdens (impaired swallowing, speech, as well as teeth-related problems (all p < 0.05)). Patients in the RT group had significantly more problems with mouth opening after six months, one, and two years (p < 0.05); (4) Conclusions: Adjuvant RT in patients with early SCC of the oral cavity and oropharynx does not seem to influence overall survival, but it positively affects progression-free survival. However, irradiated patients report a significantly decreased QL up to three years after therapy compared to the observation group.

Spin electron paramagnetic resonance of albumin for diagnosis of oral squamous cell carcinoma (OSCC).

OBJECTIVES: Albumin has a known capability to modulate free serum concentrations of proteins produced by tumour cells. The technique of spin probe labelling of albumin followed by electron paramagnetic resonance (EPR) spectroscopy may allow identification of these structural and functional changes, which regularly occur as consequence of binding tumour metabolites as ligands. The aim of the present study was a proof of principle evaluation of EPR-analysis of peripheral blood samples as possible predictor for oral squamous cell carcinoma (OSCC). MATERIAL AND METHODS: The present study is designed as gender-matched cohort. EPR was tested after retrieval of peripheral blood samples. The study group is represented by 32 patients with OSCC, and the control group consisted of 30 healthy patients. RESULTS: Overall analysis exhibited a diagnostic sensitivity of 72% (23/32 OSCC group) and a specificity of 80% (24/30 control group). Subgroup analysis revealed ten patients with elevated leukocytes (>10,000/µl; n = 9 [OSCC group] and n = 1 [control group]). After exclusion of patients with elevated white blood cell count, sensitivity considerably increased to 87% and specificity to 83%. CONCLUSION: EPR analysis of peripheral blood samples might be appropriate to support the clinician in primary and follow-up diagnosis of potential tumours such as OSCC. Unfortunately, subgroup analysis characterises the method vulnerable to inflammation. CLINICAL RELEVANCE: Nevertheless, our preliminary results are intriguing, as diagnosis of OSCC appears possible by simple peripheral blood examination. Thus, further appraisal of this novel method with inclusion of different tumour entities, systemic conditions and inflammation in a larger study population appears highly valuable.

Effectiveness of postoperative radiotherapy in patients with small oral and oropharyngeal squamous cell carcinoma and concomitant ipsilateral singular cervical lymph node metastasis (pN1) : A meta-analysis.

BACKGROUND: The positive effect of radiation therapy for patients with advanced oropharyngeal squamous cell carcinoma (OSCC) has been substantially verified. The present work investigated whether a meta-analysis of current data is able to evaluate the effectiveness of postoperative radiotherapy (PORT) in patients with small OSCC (pT1, pT2) and a single ipsilateral lymph node metastasis (pN1). METHODS: The meta-analysis comprises randomized and non-randomized studies. High-risk tumors were excluded and defined by size ≥ pT3/pT4, lymph node involvement ≥ pN2, or presence of additional histological risk factors, e.g., involved positive resection margins, extra nodal spread of the disease, or lymphangiosis carcinomatosa. The primary outcome analyzed mortality between the different treatment arms. RESULTS: Only one prospective randomized clinical trial and six retrospective observational studies were adequate for evaluation. Descriptive analysis revealed a marginally higher mortality in the irradiation group (44% vs. 34%). In contrast, a forest plot presentation of two of seven studies with and without events in the control and therapy arms presented an advantage for the irradiation group with the limitation of large heterogeneity and a lack of statistical significance. CONCLUSION: Present data are poor and exhibit limited internal and external validity; thus, direct comparison was not possible with the eligible studies. Therefore, a meta-analysis of present data may not serve as the basis for a general treatment recommendation but underlines the need of prospective, randomized, controlled clinical trials.

Immediate versus conventional loading of palatal implants in humans: a first report of a multicenter RCT.

This study aims to analyze the clinical performance of two loading concepts on second-generation palatal implants (Orthosystem, Straumann, Basel, Switzerland) in a prospective multicenter randomized controlled clinical trial. At the time of this interim analysis, 41 patients have been randomized on a 1:1 basis to one of two treatment groups. Group 1 underwent conventional loading of palatal implants after a healing period of 12 weeks (gold standard) while group 2 underwent immediate implant loading within 1 week after implant insertion. We report initial results at 6 months after functional loading. The primary outcome parameter was implant success (no implant mobility, no implant loss). The implants in both groups were initially stable at the time of insertion, and all were eligible for randomization. Twenty-two patients (group 1) were subjected to conventional implant loading after 12 weeks while 19 patients (group 2) received immediate functional loading within the first week after insertion. Direct (e.g. distal jet appliances) as well as indirect forms of anchorage (conventional or modified transpalatal arch) were used. The magnitude of orthodontic forces ranged between 1 and 4 N for the immediate loading group and between 1 and 5 N for the conventional loading group. One implant in group 1 was lost during the healing phase. One dropout was registered in group 2. Thirty-nine implants were functionally loaded for over 6 months now. These preliminary data provide first evidence of the fact that immediate loading of palatal implants yields equivalent success rates as conventional loading to 4 N after 6 months.

Modulation of platelet activation and initial cytokine release by alloplastic bone substitute materials.

OBJECTIVES: Platelet-derived cytokines play a crucial role in tissue regeneration. In regenerative dental medicine, bone substitute materials (BSM) are widely used. However, initial interactions of BSM and platelets are still unknown. The aim of this study was to evaluate the potential of platelet activation and subsequent initial cytokine release by different commercial alloplastic BSM. MATERIAL AND METHODS: Eight commercial BSM of different origins and chemical compositions (tricalcium phosphate, hydroxyapatite, bioactive glass: SiO(2) and mixtures) were incubated with a platelet concentrate (platelet-rich plasma, PRP) of three healthy volunteers at room temperature for 15 min. Platelet count, aggregation, degranulation (activated surface receptor CD62p) and cytokine release (Platelet-derived growth factor, Vascular endothelial growth factor) into the supernatant were quantified. Highly thrombogenic collagen served as a reference. RESULTS: The investigated PRP samples revealed different activation patterns when incubated with different BSM. In general, SiO(2)-containing BSM resulted in high platelet activation and cytokine release. In detail, pure bioactive glass promoted platelet activation most significantly, followed by hybrid BSM containing lower ratios of SiO(2). Additionally, we found indications of cytokine retention by BSM of large specific surfaces. CONCLUSIONS: Platelet activation as well as consecutive storage and slow release of platelet-derived cytokines are desirable attributes of modern BSM. Within the limits of the study, SiO(2)-containing BSM were identified as promising biomaterials. Further investigations on cytokine adsorption and cytokine release kinetics by the respective BSM have to be conducted.

Integration of Perforator Vessels in CAD/CAM Free Fibula Graft Planning: A Clinical Feasibility Study.

INTRODUCTION: Commercial CAD/CAM planning of free osteocutaneous microvascular fibula flap does not support integration of soft tissue structures including perforator vessel anatomy. Therefore, in a clinical trial, a method for such a combined hard- and soft tissue 3D-fibula planning was assessed. MATERIALS AND METHODS: In a clinical study on 24 patients needing reconstruction with osteocutaneous fibula graft, skin perforators of the respective leg were detected via Doppler sonography and documented on a measurement device. Each of the perforators' localization was transferred to a CAD/CAM planning software and included in each planning step as well as in the surgical cutting guide. A comparison between sonography and clinical localization, damage to perforator vessels during surgery as well as a subjective evaluation of feasibility and usefulness of the procedure was carried out. RESULTS: In total, 19 skin paddles were placed orally, 2 extraorally and 3 at both sites at once. Survival rate was 92% (22/24). In addition, 3 skin paddles were lost complete and 2 partially. Anatomical sites of perforator vessels were never < 1 cm from planned positions and not damaged at all (n = 75). Planning was judged useful for skin paddle design and positioning of osteotomies. In accordance, surgical guides were always implemented successfully without the need of changing planned procedures during surgery. CONCLUSION: Integration of skin perforators into 3D planning of microvascular fibular graft is feasible and may even decrease involuntary dissection of perforator vessels. Even so, clinical studies for comparison are needed.

Predictive values of resonance frequency analysis as a diagnostic tool in palatal implant loss.

OBJECTIVES: To determine the diagnostic value of resonance frequency analysis (RFA) in predicting palatal implant (PI) loss. MATERIALS AND METHODS: RFA values of 32 patients (study center at Mainz and Dresden) were evaluated in a prospective randomized controlled trial addressing clinical performance of two loading concepts on PI (Orthosystem, Straumann, Basel, Switzerland). Group 1: conventional loading after a 12-week healing period vs group 2: immediate loading within one week after insertion. Stability was assessed by RFA after surgical insertion (T1), one week (T2), and 12 weeks (T3) later. RESULTS: All 32 PI were clinically stable after surgical insertion; 14 PI were loaded conventionally and 18 immediately. One implant in group 1 was lost 6 weeks after insertion. One drop-out was registered in group 2. One false positive and three false negative implant stability quotients (ISQ) were observed. ISQ values of clinically stable PI in group 1 were 67.2 (SD ± 9.5) at T1, 62.3 (SD ± 11.7) at T2, and 68.2 (SD ± 5.5) at T3. Group 2 showed 67.1 (SD ± 11.7) at T1, 65.4 (SD ± 10.4) at T2, and 72.3 (SD ± 5.6) at T3. Differences between groups were not statistically significant for starting time (P = .88) and change from T1 to T2: 0.08 but were significant from T1 to T3: P = .04; (regression analysis). CONCLUSIONS: RFA had no sensitivity for prediction of stability. General decrease after primary stability and increase with secondary stability gives support for specificity. Within the limits of the study, only the diagnostic value of RFA identifying stable palatal implants could be confirmed.

Clinical and esthetic outcome with immediate insertion and provisionalization with or without connective tissue grafting in presence of mucogingival recessions: A retrospective analysis with follow-up between 1 and 8 years.

BACKGROUND: Recessions following immediate implant insertion are frequently reported in the literature. Data regarding implant installation in presence of mucogingival recessions are rare. PURPOSE: This study observes soft tissue level changes following immediate implant insertion and provisionalization of implants with or without connective tissue grafts in the anterior maxilla in patients with initial mucogingival recession within a follow-up period between one and eight years. MATERIALS AND METHODS: Twenty-six patients with marginal gingival recessions, which were designated for extraction and immediate implant insertion in the anterior zone of the maxilla (13-23), were included. Out of a larger group of immediate implants only single tooth replacements with 1 to 3 mm recession and a pre- and post-op CB-CT were selected. Facial bone deficiencies were grafted flaplessly with autologous bone in all sites. In a group of 13 patients the recessions (mean 2.3 ± 0.7 mm, range 1.0-3.0 mm) were grafted additionally by connective tissue (ABG + CTG), in the remaining 13 patients no soft tissue grafting (mean recession 1.8 ± 0.6 mm, range 1.0-3.0 mm) was performed (ABG). The marginal hard and soft tissue level, the width of the keratinized mucosa, the PES, and implant success were evaluated. RESULTS: After a mean follow-up period of 45 months the recessions were significantly reduced in the ABG group from 1.8 to 0.9 mm. The improvement was even more pronounced in the ABG + CTG group (from 2.3 to 0.5 mm). The PES improved significantly in both groups. At final examination all implants were still in function. Within the observational period, in 5 of 13 implants a marginal bone loss of more than 1 mm was noticed in the ABG, but in none of the ABG + CTG group. CONCLUSIONS: These clinical results provide evidence that immediate implant placement might improve the facial soft tissue level. This was more evident in cases with a greater recession and an additional treatment with connective tissue grafts.

Leech related Aeromonas veronii complex infection after reconstruction with a microvascular forearm flap.

Medical leeches (Hirudo medicinalis) in plastic and reconstructive surgery are often used for the treatment of vascular failure after microvascular surgery. Leeches are a reservoir for bacteria of the Aeromonas group that help digesting the blood meal. In some cases these bacteria are able to cause severe wound infections that can lead to loss of tissue transplants. We report about a patient with a common microvascular forearm flap after resection of an oral squamous cell carcinoma which got infected by Aeromonas spp. after treatment with medical leeches. Most of these species are resistant for common antibiotic treatment after surgery. This report shows the importance of an early concomitant antibiotic prophylaxis in the treatment of venous congestion with medical leeches.