Restoration of posterior teeth by narrow diameter implants in hyperglycemic and normoglycemic patients - 4-year results of a case-control study.

OBJECTIVES: To investigate the four-year clinical outcome and marginal bone loss around narrow-diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and normo-glycemic individuals. MATERIALS AND METHODS: In 11 T2DM patients with a concentration of glycated hemoglobin (HbA1C) > 6.5% (test group) and 15 normoglycemic patients (HbA1C < 6.0%; control group), one narrow-diameter tissue level implant, placed in the posterior maxilla or mandible, was investigated. The clinical parameters probing depth (PD), bleeding on probing (BOP), attachment loss (CAL), recession, and papilla bleeding index (PBI) were assessed manually after 24 and 48 months of function. The paired digital periapical radiographs were analyzed regarding the change in marginal bone level (MBL) from baseline to 48 months post-op. The technical complications were recorded. RESULTS: In the T2DM group, 11 patients were available for follow-ups. The overall implant survival rate after 48 months was 100%. The differences in means for the clinical parameters and the MBL between the T2DM and normo-glycemic patients for the observation period were statistically non-significant. No technical complications were recorded. CONCLUSIONS: The study demonstrated an encouraging clinical outcome with ND implants in patients with uncontrolled T2DM compared to non-diabetics after 48 months' post loading. CLINICAL RELEVANCE: Patients with HbA1C > 6.5% may benefit from the treatment with narrow-diameter implants by avoiding complex surgical interventions with augmentation procedures. REGISTRATION NUMBER (CLINICALTRIALS.GOV): NCT04630691.

Microcirculation and neutrophil-related cytokine concentrations are not altered around narrow diameter implants in T2DM patients during wound healing.

OBJECTIVES: The aim of this study was to assess the microcirculation and the expression patterns of wound-healing-related cytokines around narrow-diameter implants in type 2 diabetes mellitus (T2DM) and normo-glycemic patients. MATERIALS AND METHODS: A total of 31 patients, 16 of which diagnosed with T2DM (HbA1c > 6.5) and 15 normo-glycemic patients, received narrow diameter implants in the posterior mandible or maxilla. During the 3-month healing period, soft-tissue perfusion was monitored via laser Doppler flowmetry. Peri-implant fluid (PICF) was harvested and analyzed for concentrations of interleukin-1ß (IL-1ß), interleukin-23 (IL-23), interleukin-17 (IL-17), and granulocyte colony-stimulating factor (G-CSF) by a multiplex, bead-based immunoassay. RESULTS: Microcirculatory perfusion patterns during wound healing exhibited no significant differences throughout the observation period. IL-1ß concentrations were expectedly elevated during the early phases of wound healing. At the first visit after surgery, IL-23 concentrations were significantly higher in implants of diabetic patients. This difference was diminished over the course of the observation period. For the other tested analytes, no differences were observable between both groups. CONCLUSION: Wound healing after implant surgery was similar in T2DM and healthy patients. Hydrophilic-surface titanium-zirconium implants with reduced diameter may be considered for implant therapy of diabetes mellitus type II patients. REGISTRATION NUMBER: NCT04630691 (clinicaltrials.gov).

One-year performance of posterior narrow diameter implants in hyperglycemic and normo-glycemic patients-a pilot study.

OBJECTIVES: The aim of the study was to compare the performance of narrow diameter implants in patients with uncontrolled diabetes mellitus type 2 (T2DM) and normo-glycemic individuals during the first 12 months after implant loading. MATERIAL AND METHODS: In 16 T2DM patients with HbA1C > 6.5% (test group) and 16 normo-glycemic patients (HbA1C < 6.0%; control group), one to two narrow diameter tissue level implants were placed in the posterior maxilla or mandible. After 3-month lasting integration period, implants were loaded by fixed dentures. The clinical parameters probing depth (PD), bleeding on probing (BOP), attachment loss (CAL), recession and papilla bleeding index (PBI) were assessed manually at loading and after 12 months of function. The paired digital periapical radiographs were analyzed with regard to the change in marginal bone level (MBL) from baseline to 12 months' control. The mean values calculated for both patient groups were statistically analyzed. The technical complications were recorded. RESULTS: The T2DM group accounted 13 patients due to 3 dropouts. The overall implant survival rate after 12 months was 100%. The differences in means for the clinical parameters and the MBL were statistically non-significant between the T2DM and normo-glycemic patients for the short period of loaded function reported here. No technical complications were recorded. CONCLUSIONS: The study demonstrated an encouraging clinical outcome with narrow diameter implants in patients with uncontrolled T2DM compared to non-diabetics after 12 months post loading. For the short observation period, no biological and technical complications were reported regardless the glycemic status. CLINICAL RELEVANCE: Patients with HbA1C > 6.5% may benefit from the treatment with narrow diameter implants by avoiding complex surgical interventions with augmentation procedures. TRIAL REGISTRATION: Clinicaltrials.gov : NCT04630691.

Comparison of a polyethylene glycol membrane and a collagen membrane for the treatment of bone dehiscence defects at bone level implants-A prospective, randomized, controlled, multicenter clinical trial.

OBJECTIVES: The aim of the present randomized, controlled clinical multicenter trial was to compare a polyethylene glycol (PEG) and a native collagen membrane (BG) for simultaneous guided bone regeneration at bony dehiscence-type defects around bone level titanium implants. MATERIAL AND METHODS: The study enrolled 117 patients requiring implant treatment in the posterior maxilla or mandible with expected buccal bony dehiscence-type defects at the placed titanium implants. According to a parallel groups design, defects were filled with a synthetic bone filler and randomly assigned to either PEG or BG membrane. As primary parameter, the relative vertical bone fill was assessed at baseline and at re-entry after 6 months of healing. As secondary parameters, the marginal bone level (MBL) was assessed radiographically and soft tissue conditions were recorded up to 18 months postloading. RESULTS: Both groups showed comparable vertical bone fill revealing a relative change in defect height of 59.7% (PEG) and 64.4% (BG). The absolute mean reduction in defect size was 2.5 mm in the PEG group and 3.2 mm in the BG group. Although both groups revealed a statistically significant mean defect reduction (p < .001), a comparison between the two groups did not show statistical significances. The non-inferiority test with inferiority limit of -5% could not be rejected, based on the 90% confidence interval of the differences of the two means with lower limit -15.4%. After 18 months, an MBL increase of 0.45 ± 0.43 mm in the PEG group and 0.41 ± 0.81 mm in the BG group was detected (p < .001). Soft tissue complications were observed in both groups without showing statistical significance. CONCLUSIONS: Both membranes supported bone regeneration at dehiscence-type defects and obtained vertical bone fill with a relative change in defect height of 59.7% (PEG) and 64.4% (BG); however, the non-inferiority of PEG could not be shown.

Gingival biotype revisited-novel classification and assessment tool.

OBJECTIVES: To evaluate the relationship between gingival biotypes and gingival thickness based on probe transparency through the gingival margin and to assess the sensitivity of a novel classification method. MATERIAL AND METHODS: Sixty adult Caucasian subjects were stratified by their gingival biotype (GB) as defined by the transparency of a prototype double-ended periodontal probe through the buccal gingival margin into "thin" (30 subjects), "moderate" (15 subjects), and "thick" (15 subjects) GB. Three additional parameters were also assessed: gingival thickness (GT), probing depth (PD), and gingival width (GW). RESULTS: Median GT was 0.43 mm (P 25% 0.32; P 75% 0.58) for thin, 0.74 mm (P 25% 0.58; P 75% 0.81) for moderate, and 0.83 mm (P 25% 0.74; P 75% 0.95) for thick GB, respectively. GT was statistically significant different for thin versus moderate and thin versus thick, respectively (Kruskal-Wallis test, p < 0.05; Dunn's test, thin versus moderate: p = 0.002; thin versus thick: p < 0.001; moderate versus thick: p = 0.089). GW was directly correlated with GT (Spearman correlation p < 0.01). The sensitivity of the new classification tool for diagnosing a thin GB was 91.3%. No adverse events or complications were reported. CONCLUSION: GT differs significantly between the presented GB groups, hence, an alternative classification especially focusing on thin biotypes based on a modified periodontal probe might be advantageous. In addition, the presence of a thick gingiva is associated with a wide band of keratinized tissue. CLINICAL RELEVANCE: This clinical setting might to be useful to identify high-risk patients with a very thin biotype and, consequently, higher risk for gingival recession after dental treatments.

Pre-augmentation soft tissue expansion improves scaffold-based vertical bone regeneration - a randomized study in dogs.

OBJECTIVE: Soft tissue (ST) dehiscence with graft exposure is a frequent complication of vertical augmentation. Flap dehiscence is caused by failure to achieve tension-free primary wound closure and by the impairment of flap microcirculation due to surgical trauma. Soft tissue expansion (STE) increases ST quality and quantity prior to reconstructive surgery. We hypothesized that flap preconditioning using STE would reduce the incidence of ST complications after bone augmentation and that optimized ST healing would improve the outcome of bone regeneration. MATERIALS AND METHODS: Self-filling tissue expanders were implanted in mandibular bone defects in ten beagle dogs. After expansion, alloplastic scaffolds were placed for vertical bone augmentation in STE sites and in control sites without STE pre-treatment. ST flap microcirculation was analysed using laser Doppler flowmetry. The incidence of graft exposures was evaluated after 2 weeks. Bone formation was assessed after 2 months, using histomorphometry and immunohistochemistry. RESULTS: Test sites showed significantly less impairment of perfusion and faster recovery of microcirculation after bone augmentation. Furthermore, no flap dehiscences occurred in STE sites. Bone regeneration was found in both groups; however, significantly greater formation of new bone was detected in test sites with preceding STE. CONCLUSIONS: Preconditioning using STE improved ST healing and bone formation after vertical augmentation. The combination of STE and the subsequent placement of alloplastic scaffolds may facilitate the reconstruction of severe bone defects.

Early Healing Events after Periodontal Surgery: Observations on Soft Tissue Healing, Microcirculation, and Wound Fluid Cytokine Levels.

Early wound healing after periodontal surgery with or without enamel matrix derivative/biphasic calcium phosphate (EMD/BCP) was characterized in terms of soft tissue closure, changes of microcirculation, and expression of pro- and anti-inflammatory cytokines in gingival crevicular fluid/wound fluid (GCF/WF). Periodontal surgery was carried out in 30 patients (18 patients: application of EMD/BCP for regeneration of bony defects; 12 patients: surgical crown lengthening (SCL)). Healthy sites were observed as untreated controls. GCF/WF samples were collected during two post-surgical weeks. Flap microcirculation was measured using laser Doppler flowmetry (LDF). Soft tissue healing was evaluated after two weeks. GCF/WF levels of interleukin 1ß (IL-1ß), tumour necrosis factor (TNF-α), IL-6, and IL-10 were determined using a multiplex immunoassay. Surgery caused similar reductions of flap microcirculation followed by recovery within two weeks in both EMD/BCP and SCL groups. GCF/WF and pro-inflammatory cytokine levels were immediately increased after surgery, and returned only partially to baseline levels within the two-week observation period. Levels of IL-10 were temporarily reduced in all surgical sites. Flap dehiscence caused prolonged elevated levels of GCF/WF, IL-1ß, and TNF-α. These findings show that periodontal surgery triggers an immediate inflammatory reaction corresponding to the early inflammatory phase of wound healing, and these inflammation measures are temporary in case of maintained closure of the flap. However, flap dehiscence causes prolonged inflammatory exudation from the periodontal wound. If the biological pre-conditions for periodontal wound healing are considered important for the clinical outcome, care should be taken to maintain primary closure of the flap.

Are periodontal diseases really silent? A systematic review of their effect on quality of life.

AIM: Periodontal diseases (PDs) may play an important role in the effect oral health status has on a person's quality of life (QoL). The objective was to investigate the influence of PDs (gingivitis and periodontitis) on oral health-related QoL (OHRQoL) by systematically reviewing the literature. MATERIALS AND METHODS: Studies using clinical periodontal examinations and validated survey instruments were included. Among 1134 citations initially identified through electronic and hand searching, 37 were eligible and data were extracted from full texts. A vote counting method was used for synthesis of the results. RESULTS: Included studies were published between 2001 and 2014 and revealed considerable heterogeneity in participant selection, clinical assessments, and OHRQoL measures. A significant association between PDs and OHRQoL was reported in 28 studies, of which eight reported increasing impact with greater disease severity or extent. CONCLUSIONS: Within the limits of the available literature, OHRQoL was affected by clinically assessed PDs. There was evidence for increased impairment with greater severity and extent of PDs, and the recognition of the association was increased when full mouth recording protocols were applied.

Validation of an innovative instrument of Positive Oral Health and Well-Being (POHW).

INTRODUCTION: Most existing measures of oral health focus solely on negative oral health, illness, and deficiencies and ignore positive oral health. In an attempt to commence exploration of this challenging field, an innovative instrument was developed, the "Positive Oral Health and Well-Being" (POHW) index. This study aimed to validate this instrument and to explore an initial model of the pathway between oral health attributes and positive oral health. METHODS: A cross-sectional, multicenter study (Israel, USA, and Germany), was conducted. Our conceptual model suggests that positive oral health attributes, which integrate with positive unawareness or positive awareness on the one hand and with positive perception on the other hand, may result via appropriate oral health behavior on positive oral health. The 17-item self-administered index was built on a theoretical concept by four experts from Israel and Germany. Reliability, factor, and correlation analyses were performed. For external correlations and to measure construct validity of the instrument, we utilized the oral health impact profile-14, self-perceived oral impairment, life satisfaction, self-perceived well-being, sociodemographic and behavioral data, and oral health status indices. RESULTS: Four hundred and seventy participants took part in our three-center study. The combined data set reliability analyses detected two items which were not contributing to the index reliability. Thus, we tested a 15-item construct, and a Cronbach's α value of 0.933 was revealed. Primary factor analysis of the whole sample indicated three subconstructs which could explain 60 % of variance. Correlation analyses demonstrated that the POHW and OHIP-14 were strongly and negatively associated. The POHW correlated strongly and positively with general well-being, moderately with life satisfaction, and weakly with the perceived importance of regular dental checkups. It correlated moderately and negatively with perceived oral impairment, and marginally and negatively with dental caries experience (DMFT) and periodontal health status (CPI) scores. When DMFT and CPI clinical measurements were categorized, a higher score of POHW was revealed for better oral health. DISCUSSION: Our study introduced a new instrument with good reliability and sound correlations with external measures. This instrument is the first to allow measurability of positive instead of impaired oral health. We utilized subjective-psychological and functional-social measures. The current results indicate that by further exploring our conceptual model, POHW may be of importance for identifying patients with good and poor oral health, and building an effective and inexpensive strategy for prevention, by being able to evaluate the effect of interventions in a standardized way.

On the relationship between gingival morphotypes and different crown shape assessments in young Caucasians.

OBJECTIVES: The objective of this study was to determine the relationship between crown length as well as crown width and gingival morphotypes (primary aim) and their correlation with tooth shape and papilla height (secondary aim). MATERIAL AND METHODS: Thirty-six adult subjects were evaluated in this clinical study according to their gingival morphotype (GM) defined by transparency of a periodontal probe through the buccal gingival margin. Eighteen subjects comprised the thin entity group and 18 the control group thick entity, respectively. Besides crown length (CL) and crown width (CW), two different methods to assess crown shape (CW/CL ratio) were compared and analysis of their relation to papilla height was performed. RESULTS: Nineteen female and 17 male volunteers were enrolled in this study, with a mean age of 24.9 years (±3.4; minimum 18, maximum 35). A statistical significant difference for the crown length could be detected between both groups (p < 0.05) but not for crown width. No significant difference was found for apical or coronal CW/CL ratio besides on tooth 22. CONCLUSION: Within the limitations of this study and within this young Caucasian study population, only crown length seems to have an association with different gingival morphotypes. Furthermore, papilla height and crown shape do not have a clear correlation on tooth level. CLINICAL RELEVANCE: Crown shape seems to be not a strong parameter in assessing the gingival morphotype.

Improvement of microcirculation and wound healing in vertical ridge augmentation after pre-treatment with self-inflating soft tissue expanders - a randomized study in dogs.

OBJECTIVES: We investigated the effect of soft tissue expansion (STE) on vertical ridge augmentation with regard to the incidence of wound dehiscences and the impairment of microcirculation in dogs, and the applicability of laser Doppler flowmetry (LDF) to explore the relation between microcirculation and wound healing. MATERIAL AND METHODS: Bone defects were created on both mandibular sides in ten beagle dogs by extraction of premolars and removal of bone. Six weeks later, self-filling tissue expanders were implanted in randomly assigned test sites. After 5 weeks of expansion, vertical augmentation was carried out in test and control sites using calvarial onlay grafts side by side with granular biphasic calcium phosphate covered with a resorbable polyethylene glycol membrane. Microcirculation was evaluated with laser Doppler flowmetry (LDF). The incidence of wound dehiscences was evaluated after 2 weeks. The validity of LDF to predict dehiscences was evaluated by construction of receiver operating characteristic (ROC) curves. RESULTS: After augmentation, test sites showed significantly better perfusion than control sites without preceding STE (P = 0.012). Three days after surgery, perfusion was still significantly decreased in control sites (P = 0.005), while microcirculation in test sites had returned to pre-surgical levels. After 2 weeks, healing in test sites was good, whereas eight dehiscences were found in control sites (P = 0.002). ROC curves showed that microcirculation levels immediately after augmentation surgery significantly predicted subsequent wound dehiscences (AUC = 0.799, CI 0.642-0.955, P = 0.006). CONCLUSIONS: Laser Doppler flowmetry is suitable for evaluation of soft tissue microcirculation after ridge augmentation. STE reduced the impairment of microcirculation caused by vertical ridge augmentation and decreased the incidence of wound dehiscences in the investigated animal model.

Tissue reactions after simultaneous alveolar ridge augmentation with biphasic calcium phosphate and implant insertion--histological and immunohistochemical evaluation in humans.

OBJECTIVES: Simultaneous lateral augmentation and implant placement is considered as standard procedure in deficient edentulous ridges in oral implantology. Histological studies monitoring osteogenesis after application of alloplastic bone substitutes in humans are scarce. Bone formation upon simultaneous augmentation with biphasic calcium phosphate (BCP) and implantation was histologically investigated after 6 months in situ. The results of this secondary analysis are reported tempting to ascribe specific observations to uneventful submerged healing or compromised healing of soft tissues including occurrence of dehiscences and premature graft exposure. MATERIALS AND METHODS: Histology of biopsies from lateral, crestal bone augmentations using alloplastic BCP comprising seven sites with compromised, prematurely exposed healing and six sites with uneventful submerged healing was investigated for expression of osteogenic, osteoclastogenic, and angiogenic differentiation markers. RESULTS: Histology revealed alkaline phosphatase (ALP)-positive osteoblasts and immunoreactivity for osteogenic markers osteocalcin and collagen type I in biopsies with submerged healing, while inflammatory infiltrates and accumulations of multinucleated giant cells around BCP granules were observed in compromised sites. All specimens presented adequate vessel density. Multinucleated giant cells showed inconsistent staining for the osteoclast marker tartrate-resistant acid phosphatase (TRAP). CONCLUSIONS: The histological findings of this study indicate an osteoconductive nature of the BCP applied. Premature exposure of the bone substitute reduced new bone formation and may bear a risk for inflammatory and foreign body reactions. CLINICAL RELEVANCE: A predictable appositional bone formation in simultaneously augmented sites using BCP is linked to an uneventful healing process.

Submucosal implantation of soft tissue expanders does not affect microcirculation.

AIM: To investigate the effect of submucosal implantation of self-filling osmotic tissue expanders on mucosal microcirculation. MATERIAL AND METHODS: In ten beagle dogs, all premolars were extracted on both sides of the mandible. Tooth-supporting bone and excess soft tissue were removed to mimic a severely resorbed edentulous ridge. Six weeks later, tissue expanders with 0.7 ml final volume were implanted into a submucosal pouch at randomly selected test sites, while contralateral sites served as untreated controls. Microcirculation was assessed in perfusion units (PU) before surgery, after local anaesthesia, directly after surgery, and after 1 and 3 days, using Laser Doppler flowmetry. RESULTS: Local anaesthesia caused a significant decrease of blood flow from baseline (zero) to -6.4 PU (median; Q1 -10.5; Q3 -0.9; P = 0.006); however, no additional significant decrease was recorded after completion of surgery. Blood flow showed significant increases to -3.6 PU (median; Q1 -11.3, Q3 2.1; P = 0.02) and -4.0 PU (median; Q1 -9.2, Q3 1.1; P = 0.013) after 1 and 3 days, respectively, when compared to the measurements obtained after application of local anaesthesia and completion of surgery. Blood flow had returned to unimpaired baseline levels 1 day after surgery (P > 0.05). CONCLUSIONS: Submucosal implantation of self-filling osmotic tissue expanders results in only momentary disturbance of microcirculation. The minor impairment of perfusion may explain the consistently good outcomes of submucosal implantation of these tissue expanders.

Receptor activator of NF-kappaB ligand (RANKL) and CD 31 expressions in chronic periodontitis patients before and after surgery.

AIM OF THE STUDY: The present study investigated the hypothesis that upregulation of receptor activator of NF-kappaB ligand (RANKL) expression may be associated with upregulation of endothelial cell activitiy, which is common for periods of periodontal bone loss in chronic periodontitis. MATERIAL AND METHODS: RANKL expression of activated cells in soft tissue biopsies with CD 31 activity and the presence of RANKL and osteoprotegerin (OPG) in gingival crevicular fluid (GCF) were assessed in chronic periodontitis patients. Biopsies from 17 patients and 10 healthy subjects were immunohistochemically analyzed. Clinical measurements [plaque index (PI), the gingival index (GI), probing pocket depth (PPD), clinical attachment level (CAL) and gingival bleeding index (GBI)] and GCF samples were obtained before and after periodontal therapy. RESULTS: CD31 staining did not support the assumption that endothelium-like cells were predominantly associated with RANKL expression. CONCLUSIONS: RANKL-positive cells were widely distributed in periodontitis patients giving only partial support to the hypothesis that RANKL expression is restricted to T- and B-cell activation.

Reconstructive Approach in Residual Periodontal Pockets with Biofunctionalized Heterografts-A Retrospective Comparison of 12-Month Data from Three Centers.

The regenerative capacity of well-preserved blood clots may be enhanced by biologics like enamel matrix derivative (EMD). This retrospective analysis compares outcomes reported by three centers using different heterografts. Center 1 (C1) treated intrabony defects combining cross-linked high-molecular-weight hyaluronic acid (xHyA) with a xenograft; center 2 (C2) used EMD with an allograft combination to graft a residual pocket. Center 3 (C3) combined xHyA with the placement of a resorbable polymer membrane for defect cover. Clinical parameters, BoP reduction, and radiographically observed defect fill at 12-month examination are reported. The 12-month evaluation yielded significant improvements in PPD and CAL at each center (p < 0.001, respectively). Analyses of Covariance revealed significant improvements in all parameters, and a significantly greater CAL gain was revealed for C2 vs. C1 (p = 0.006). Radiographic defect fill presented significantly higher scores for C2 and C3 vs. C1 (p = 0.003 and = 0.014; C2 vs. C3 p = 1.00). Gingival recession increased in C1 and C3 (p = 1.00), while C2 reported no GR after 12 months (C2:C1 p = 0.002; C2:C3 p = 0.005). BoP tendency and pocket closure rate shared similar rates. Within the limitations of the study, a data comparison indicated that xHyA showed a similar capacity to enhance the regenerative response, as known for EMD. Radiographic follow-up underlined xHyA's unique role in new attachment formation.

Microbiological Effects of Sodium Hypochlorite/-Amino Acids and Cross-linked Hyaluronic Acid Adjunctive to Non-surgical Periodontal Treatment.

PURPOSE: To investigate the microbiological outcomes obtained with either subgingival debridement (SD) in conjunction with a gel containing sodium hypochlorite and amino acids followed by subsequent application of a cross-linked hyaluronic acid gel (xHyA) gel, or with SD alone. MATERIALS AND METHODS: Forty-eight patients diagnosed with stages II-III (grades A/B) generalised periodontitis were randomly treated with either SD (control) or SD plus adjunctive sodium hypochlorite/amino acids and xHyA gel (test). Subgingival plaque samples were collected from the deepest site per quadrant in each patient at baseline and after 3 and 6 months. Pooled sample analysis was performed using a multiplex polymerase chain reaction (PCR)-based method for the identification of detection frequencies and changes in numbers of the following bacteria: Aggregatibacter actinomycetemcomitans (A.a), Porphyromonas gingivalis (P.g), Tannerella forsythia (T.f), Treponema denticola (T.d), and Prevotella intermedia (P.i). RESULTS: In terms of detection frequency, in the test group, statistically significant reductions were found for P.g, T.f, T.d and P.i (p < 0.05) after 6 months. In the control group, the detection frequencies of all investigated bacterial species at 6 months were comparable to the baseline values (p > 0.05). The comparison of the test and control groups revealed statistically significant differences in detection frequency for P.g (p = 0.034), T.d (p < 0.01) and P.i (p = 0.02) after 6 months, favouring the test group. Regarding reduction in detection frequency scores, at 6 months, statistically significant differences in favour of the test group were observed for all investigated bacterial species: A.a (p = 0.028), P.g (p = 0.028), T.f (p = 0.004), T.d (p <0.001), and P.i (p = 0.003). CONCLUSIONS: The present microbiological results, which are related to short-term outcomes up to 6 months post-treatment, support the adjunctive subgingival application of sodium hypochlorite/amino acids and xHyA to subgingival debridement in the treatment of periodontitis.

Histological evaluation of different abutments in the posterior maxilla and mandible: an experimental study in humans.

OBJECTIVES: To histologically evaluate and compare the performance of healing abutments with either hydrophobic or hydrophilic surface properties in humans. MATERIALS AND METHODS: According to a parallel-group design, titanium implants placed in the posterior mandible and maxilla of 30 patients were randomly assigned to either (1) hydrophobic machined (M), (2) chemically modified hydrophilic (mod) acid etched (MA) titanium (Ti) (modMA1) or (3) modMA Ti- Zirconium alloy (modMA2) healing abutments and left to heal in a transmucosal position. At 8 weeks, the abutments and a limited soft tissue biopsy were harvested according to a standardized procedure and processed for histological analysis (primary outcomes: percentage epithelial- (EC) and subepithelial connective tissue contact (CTC) to the abutment surface). RESULTS: The surgical procedure was associated with an incomplete mucosal coverage of the study abutments in nine patients, and an unintentional submerged healing procedure in three patients. Per protocol analysis (18 patients) has pointed to an improved quantitative EC [modMA2 (53.45 ± 28.25) > modMA1 (32.25 ± 24.3) > M (23.15 ± 16.09)] and CTC [modMA2 (75.12 ± 43.22) > modMA1 (69.41 ± 46.74) > M (47.63 ± 19.28)] (%) to modMA surfaced abutments. CONCLUSIONS: It was concluded that modMA surfaces may have the potential to enhance soft tissue adhesion at the transmucosal aspect of titanium dental implants.

The "Tunneled Sandwich" Technique for Preserving the Buccal Tissue Volume After Immediate Implantation: A Retrospective Report of 10 Cases.

Tooth loss or extraction is associated with significant reduction in alveolar ridge volume, extensively expressed in the anterior zone, and immediate implant placement is insufficient to overcome this problem. The proposed approach combined immediate implant placement with buccal tissue enhancement by applying a crosslinked collagen matrix hydrated with crosslinked hyaluronic acid (xHyA). All 10 cases presented with a retained but narrow buccal socket wall, so immediate implant placement with the "tunneled sandwich" technique was performed after tooth extraction. The tunneled sandwich technique helped create a subperiosteal pouch for insertion of the collagen matrix buccal to the alveolar bone crest. The implants healed transmucosally by receiving either a gingiva former or an immediate temporary restoration. Ten sites in 10 patients demonstrated stable, noninflamed peri-implant conditions and suitable ridge volume at the implant neck and achieved high pink esthetic scores 6 months after implant loading. The tunneled sandwich technique is a suitable method to preserve buccal volume, which biologically and esthetically contributes to favorable long-term results.

Prenyltransferase gene expression reveals an essential role of prenylation for the inflammatory response in human gingival fibroblasts.

BACKGROUND: Prenyltrasferases (PTases) are a class of enzymes known to be responsible for promoting posttranslational modification at the carboxyl terminus of proteins containing a so-called CaaX-motif. The process is responsible for proper membrane localization and the appropriate function of several intracellular signaling proteins. Current research demonstrating the pathomechanistic importance of prenylation in inflammatory illnesses emphasizes the requirement to ascertain the differential expression of PT genes under inflammatory settings, particularly in periodontal disease. METHODS: Telomerase-immortalized human gingival fibroblasts (HGF-hTert) were cultured and treated with either inhibitors of prenylation (PTI) lonafarnib, tipifarnib, zoledronic acid, or atorvastatin at concentrations of 10 µM in combination with or without 10 µg Porphyromonas gingivalis lipopolysaccharide (LPS) for 24 h. Prenyltransferase genes FNTB, FNTA, PGGT1B, RABGGTA, RABGGTB, and PTAR1 as well as inflammatory marker genes MMP1 and IL1B were detected using quantitative real-time polymerase chain reaction (RT-qPCR). Immunoblot and protein immunoassay were used to confirm the results on the protein level. RESULTS: RT-qPCR experiments revealed significant upregulation of IL1B, MMP1, FNTA, and PGGT1B upon LPS treatment. PTase inhibitors caused significant downregulation of the inflammatory cytokine expression. Interestingly, FNTB expression was significantly upregulated in response to any PTase inhibitor in combination with LPS, but not upon LPS treatment only, indicating a vital role of protein farnesyltransferase in the proinflammatory signaling cascade. CONCLUSIONS: In this study, distinct PTase gene expression patterns in pro-inflammatory signaling were discovered. Moreover, PTase inhibiting drugs ameliorated inflammatory mediator expression by a significant margin, indicating that prenylation is a major pre-requisite for innate immunity in periodontal cells.

Alveolar ridge alterations after lateral guided bone regeneration with and without hyaluronic acid: a prospective randomized trial with morphometric and histomorphometric evaluation.

OBJECTIVE: To clinically and histologically evaluate the potential effect of a cross-linked, high molecular weight hyaluronic acid (xHyA) on the outcomes of guided bone regeneration performed with a demineralized bovine bone mineral (DBBM) covered with a natural collagen membrane. METHOD AND MATERIALS: Eleven patients (eight females and three males, mean age 53 years) with a total of 27 surgical sites were treated. Treatments were performed with either DBBM and natural collagen membrane fixed with tacks (group A) or DBBM mixed with xHyA and subsequently covered with natural collagen membrane (group B). Clinical evaluations were made at baseline (T1), immediately after guided bone regeneration (T2), and at the time of implant placement (T3). Additionally, at the time of implant placement, core biopsies were retrieved and submitted for histologic analysis. RESULTS: Healing was uneventful in all cases. At 6 months, group B revealed a statistically significantly higher crestal ridge dimension compared to group A (P = .007). The histologic analysis revealed a tendency for greater mineralized tissue formation in group B compared to group A (67.5% versus 41.6%) and contained a higher amount of new bone (37.2%) and less DBBM residues (20.9%) than group A (12.8% new bone and 28.8% DBBM residues, respectively). CONCLUSIONS: Within their limits, the present data indicate that, during guided bone regeneration with natural collagen membrane, the combination of DBBM and xHyA may improve the quality and quantity of bone formed with DBBM alone.