The importance of soft tissue condition in bone regenerative procedures to ensure long-term peri-implant health.

Bone regenerative procedures have been widely proved to be a reliable treatment option to re-create the ideal pre-implant clinical conditions. Nevertheless, these techniques are not free from post-operative complications which might result in implant failure. Consequently, as demonstrated by the increasing recently published evidence, a careful pre- and intra-operative flap evaluation to ensure an ideal and hermetic tension-free wound closure is of paramount importance to successfully treat bony defects. In this respect, several surgical interventions mainly aimed to increase the amount of keratinized mucosa either to allow an optimal healing after a reconstructive procedure or to establish an optimal peri-implant soft tissue seal have been proposed. The present review summarizes the level of evidence on the surgical clinical aspects which have an impact on the soft tissue handling associated with bone reconstructive procedures and on the importance of soft tissue conditions to enhance and maintain peri-implant health in the long-term.

Influence of soft tissue augmentation procedures around dental implants on marginal bone level changes-A systematic review.

OBJECTIVES: This systematic review assessed the influence of soft tissue augmentation procedures on marginal bone level changes in partial or fully edentulous patients. MATERIAL AND METHODS: We identified three relevant PICO questions related to soft tissue augmentation procedures and conducted a systematic search of four major electronic databases for clinical studies in systemically healthy patients receiving at least one dental implant and a minimum follow-up of one year after implant placement. The primary outcome was mean difference in marginal bone levels, and secondary outcomes were clinical and patient-related outcomes such as thickness of peri-implant mucosa, bleeding indices, and Pink Esthetic Score. RESULTS: We identified 20 publications reporting on 16 relevant comparisons. Studies varied considerably and thus only two meta-analyses could be performed. This systematic review showed that: Soft tissue augmentation either for augmentation of keratinized mucosa or soft tissue volume inconsistently had an effect on marginal bone level changes when compared to no soft tissue augmentation, but consistently improved secondary outcomes. The combination soft and hard tissue augmentation showed no statistically significant difference in terms of marginal bone level changes when compared to hard tissue augmentation alone, but resulted in less marginal soft tissue recession as shown by a meta-analysis. Soft or hard tissue augmentation performed as contour augmentations resulted in comparable marginal bone level changes. CONCLUSIONS: Peri-implant soft and hard tissues seem to have a bidirectional relationship: "Bone stands hard, but soft tissue is the guard".

Soft tissue management at implants: Summary and consensus statements of group 2. The 6th EAO Consensus Conference 2021.

OBJECTIVES: The task of working Group 2 at the 6th Consensus Meeting of the European Association for Osseointegration was to comprehensively assess the effects of soft tissue augmentation procedures at dental implant sites on clinical, radiographic and patient-reported outcome measures (PROMs) including an overview on available outcome measures and methods of assessment. MATERIALS AND METHODS: Three systematic reviews and one critical review were performed in advance on (i) the effects of soft tissue augmentation procedures on clinical, radiographic and aesthetic outcomes, (ii) reliability and validity of outcome measures and methods of assessment and (iii) PROMs applied in clinical studies for soft tissue augmentation procedures at dental implant sites. Major findings, consensus statements, clinical recommendations and implications for future research were discussed in the group and approved during the plenary sessions. RESULTS: The four reviews predominantly revealed: Soft tissue augmentation procedures in conjunction with immediate and delayed implant placement result in superior aesthetic outcomes compared to no soft tissue augmentation in the zone of aesthetic priority. Soft tissue augmentation procedures have a limited effect on marginal bone level changes compared to implant sites without soft tissue augmentation. Clinically relevant parameters (gingival index, mucosal recession) and plaque control improve at implant sites when the width of keratinised mucosa is increased. A variety of aesthetic indices have been described with good reliability. Pink Esthetic Score and Complex Esthetic Index are the most validated aesthetic indices for single implants, though. Superimposed digital surface scans are most accurate to assess profilometric tissue changes. PROMs following soft tissue augmentation procedures have been assessed using various forms of questionnaires. Soft tissue augmentation had a limited effect on PROMs. CONCLUSIONS: Soft tissue augmentation procedures are widely applied in conjunction with implant therapy. Depending on the indication of these interventions, clinical, radiographic and aesthetic outcomes may improve, whereas the effect on PROMs is limited.

Crestal bone loss due to abutment manipulation and an internal silver deposition implant design in a canine model.

OBJECTIVE: The study aimed to evaluate the effect of internal silver coating as a countermeasure to crestal bone loss around implants with or without multiple abutment disconnections/reconnections. MATERIALS AND METHODS: Following tooth extraction, 48 implants with connected healing abutments (24 implants internally coated with elemental silver) were placed in the mandible of eight beagle dogs. Two months after implant surgery one side of the mandible was randomly assigned to four abutment manipulations (disconnection/reconnection) on a weekly basis. At 4 months postoperative, biopsies were obtained and prepared for histomorphometric analysis. RESULTS: Healing abutment manipulation increased crestal bone remodeling when compared to no abutment manipulation (1.28 mm versus 0.92 mm, respectively), although the difference was not statistically significant (p = 0.0836). Overall, an internal silver coating did not provide a statistically sufficient implant treatment characteristic as a countermeasure to crestal bone loss (p = 0.7801). CONCLUSIONS: These findings indicate that the controlled variables explored here (abutment manipulation/internal silver coating) have a limited effect on initial crestal bone loss. CLINICAL RELEVANCE: Abutment manipulation during prosthetic work does not seem to harm the peri-implant soft and hard tissues.

The Why, What, How and What if-The method to present your research and clinical cases.

BACKGROUND: During the fourth Summer Camp (SC) held by the European Association of Osseointegration (EAO), 20 junior representatives from various European and non-European universities and associations were selected to partake in oral presentation and communication skill development. AIMS: The aim of the EAO Summer Camp (EAO SC) was to identify new methods of enhancing participants' abilities to engage, influence and lead in a professional environment, on both a clinical and scientific level. MATERIALS AND METHODS: Four different groups were assigned to discuss one of two topics: (1) an Implant Register and (2) Digital Dentistry. The method that was used during the EAO SC, for training presentation skills, was the 4MAT learning model. The 4MAT learning model is a framework for creating an engaged, dynamic and more involved style of training by accurately visualizing the learning process that each learner goes through. RESULTS AND CONCLUSIONS: All four groups, including each participant, presented outcomes in the format of 4MAT learning model answering four key questions, the Why, the What, the How and the What if. After the event, each group prepared a written summary of the thought processes. The outcome of the summer camp, for the chosen participants, was gaining skills to engage and influence in a professional environment, both clinically and scientifically. It was also expected from participants to share gained knowledge in their own respective environments after the EAO Summer Camp had ended. In conclusion, most of participants gained a valuable insight into presentation skills and also demonstrated their enthusiasm by presenting their experience at universities, institutes and clinics.

Management of the extraction socket and timing of implant placement: Consensus report and clinical recommendations of group 3 of the XV European Workshop in Periodontology.

BACKGROUND: The transition from a tooth requiring extraction to its replacement (with a dental implant) requires a series of clinical decisions related to timing, approach, materials, cost-effectiveness and the assessment of potential harm and patient preference. This workshop focused on the formulation of evidence-based consensus statements and clinical recommendations. METHODS: Four systematic reviews covering the areas of alveolar ridge preservation/bone grafting, immediate early and delayed implant placement and alveolar bone augmentation at the time of implant placement in a healed ridge formed the basis of the deliberations. The level of evidence supporting each consensus statement and its strength was described using a modification of the GRADE tool. RESULTS: The evidence base for each of the relevant topics was assessed and summarized in 23 consensus statements and 12 specific clinical recommendations. The group emphasized that the evidence base mostly relates to single tooth extraction/replacement; hence, external validity/applicability to multiple extractions requires careful consideration. The group identified six considerations that should assist clinicians in clinical decision-making: presence of infection, inability to achieve primary stability in the restoratively driven position, presence of a damaged alveolus, periodontal phenotype, aesthetic demands and systemic conditions. CONCLUSIONS: A substantial and expanding evidence base is available to assist clinicians with clinical decision-making related to the transition from a tooth requiring extraction to its replacement with a dental implant. More high-quality research is needed for the development of evidence-based clinical guidelines.

Impact of anti-infective periodontal therapy on parameters of vascular health.

AIM: This study assessed the impact of anti-infective periodontal therapy on the status of vascular health. MATERIALS AND METHODS: Periodontal and vascular health of 55 patients with severe untreated chronic periodontitis was evaluated before and 12 months after anti-infective periodontal therapy. Observed parameters were bleeding on probing (BoP), pocket probing depth (PPD), periodontal inflamed surface area index (PISA), pulse wave velocity (PWV), augmentation index (AIx), central pulse pressure (PPao) and peripheral systolic pressure (RRsys). RESULTS: ΔPISA (baseline-12 months) correlated with ΔPWV (τ 0.21; p < .03), ΔAIx (τ 0.29; p < .002) and ΔPPao (τ 0.23; p < .02). ΔBoP% (baseline-12 months) correlated with ΔPWV (τ 0.18; p < .05) and ΔAIx (τ 0.25; p < .01), while mean ΔPPD (baseline-12 months) correlated with ΔPWV (τ 0.24; p < .01) and ΔAIx (τ 0.21; p < .03). Grouping patients evenly into three groups based on tertiles of BoP resolution after 12 months revealed a significant decrease in the observed PWV median value by -0.6 m/s (p < .04) in the best response tertile (ΔBoP ≥ 88%). In the worst response tertile (ΔBoP ≤ 66%), by contrast, significant increase in PPao (+10.5 mmHg; p < .02) and AIx (+5.5; p < .02) was observed. CONCLUSION: Efficacious resolution of periodontal inflammation may beneficially impact on vascular health.

The severity of human peri-implantitis lesions correlates with the level of submucosal microbial dysbiosis.

AIM: To cross-sectionally analyse the submucosal microbiome of peri-implantitis (PI) lesions at different severity levels. MATERIALS AND METHODS: Microbial signatures of 45 submucosal plaque samples from untreated PI lesions obtained from 30 non-smoking, systemically healthy subjects were assessed by 16s sequencing. Linear mixed models were used to identify taxa with differential abundance by probing depth, after correction for age, gender, and multiple samples per subject. Network analyses were performed to identify groups of taxa with mutual occurrence or exclusion. Subsequently, the effects of peri-implant probing depth on submucosal microbial dysbiosis were calculated using the microbial dysbiosis index. RESULTS: In total, we identified 337 different taxa in the submucosal microbiome of PI. Total abundance of 12 taxa correlated significantly with increasing probing depth; a significant relationship with lower probing depth was found for 16 taxa. Network analysis identified two mutually exclusive complexes associated with shallow pockets and deeper pockets, respectively. Deeper peri-implant pockets were associated with significantly increased dysbiosis. CONCLUSION: Increases in peri-implant pocket depth are associated with substantial changes in the submucosal microbiome and increasing levels of dysbiosis.

Guidelines for development of Implant Dentistry in the next 10 years regarding innovation, education, certification, and associations.

BACKGROUND: During the third Summer Camp of European Association of Osseointegration (EAO), 40 junior representatives from various European societies and associations were brought together to discuss and explore the following topics in Implant Dentistry in the next 10 years: (I) certification, (II) societies and associations, (III) continuing education, and (IV) innovations. AIMS: The aims of all working groups were to identify and outline the present situation in the area of the selected topic and to propose improvements and innovations to be implemented in the following 10 years. MATERIALS AND METHODS: Four different groups were assigned randomly to one of the four working units. The method to discuss the selected topics was World Cafè. The summaries of four topics were then given to all participants for peer review. RESULTS AND CONCLUSIONS: All four groups presented the conclusions and guidelines accordingly: (I) The recognition for Implant Dentistry and accreditation of training programs would lead to an improvement of the quality of care to the benefit of the patients; (II) Dental associations and societies have to continuously improve communication to meet needs of dental students, professionals, and patients (III) European Dental Board should be installed and become responsible for continue dental education; (IV) dental engineering, peri-implant diseases, and digital workflow in dentistry currently have limited tools that do not guarantee predictable results.

Group 1 ITI Consensus Report: The influence of implant length and design and medications on clinical and patient-reported outcomes.

OBJECTIVES: The aim of Working Group 1 was to address the influence of different local (implant length, diameter, and design) and systemic (medications) factors on clinical, radiographic, and patient-reported outcomes in implant dentistry. Focused questions on (a) short posterior dental implants (≤6 mm), (b) narrow diameter implants, (c) implant design (tapered compared to a non-tapered implant design), and (d) medication-related dental implant failures were addressed. MATERIALS AND METHODS: Four systematic reviews were prepared in advance of the Consensus Conference and were discussed among the participants of Group 1. Consensus statements, clinical recommendations, and recommendations for future research were based on structured group discussions until consensus was reached among the entire expert Group 1. The statements were then presented and accepted following further discussion and modifications as required by the plenary. RESULTS: Short implants (≤6 mm) revealed a survival rate ranging from 86.7% to 100%, whereas standard implant survival rate ranged from 95% to 100% with a follow-up from 1 to 5 years. Short implants demonstrated a higher variability and a higher Risk Ratio [RR: 1.24 (95% CI: 0.63, 2.44, p = 0.54)] for failure compared to standard implants. Narrow diameter implants (NDI) have been classified into three categories: Category 1: Implants with a diameter of <2.5 mm ("Mini-implants"); Category 2: Implants with a diameter of 2.5 mm to <3.3 mm; Category 3: Implants with a diameter of 3.3 mm to 3.5 mm. Mean survival rates were 94.7 ± 5%, 97.3 ± 5% and 97.7 ± 2.3% for category 1, 2 and 3. Tapered versus non-tapered implants demonstrated only insignificant differences regarding clinical, radiographic, and patient-reported outcomes. The intake of certain selective serotonin reuptake inhibitors and proton pump inhibitors is associated with a statistically significant increased implant failure rate. The intake of bisphosphonates related to the treatment of osteoporosis was not associated with an increased implant failure rate. CONCLUSIONS: It is concluded that short implants (≤6 mm) are a valid option in situations of reduced bone height to avoid possible morbidity associated with augmentation procedures; however, they reveal a higher variability and lower predictability in survival rates. Narrow diameter implants with diameters of 2.5 mm and more demonstrated no difference in implant survival rates compared to standard diameter implants. In contrast, it is concluded that narrow diameter implants with diameters of less than 2.5 mm exhibited lower survival rates compared to standard diameter implants. It is further concluded that there are no differences between tapered versus non-tapered dental implants. Certain medications such as selective serotonin reuptake inhibitors and proton pump inhibitors showed an association with a higher implant failure rate.

Group 5 ITI Consensus Report: Digital technologies.

OBJECTIVES: Working Group 5 was assigned the task to review the current knowledge in the area of digital technologies. Focused questions on accuracy of linear measurements when using CBCT, digital vs. conventional implant planning, using digital vs. conventional impressions and assessing the accuracy of static computer-aided implant surgery (s-CAIS) and patient-related outcome measurements when using s-CAIS were addressed. MATERIALS AND METHODS: The literature was systematically searched, and in total, 232 articles were selected and critically reviewed following PRISMA guidelines. Four systematic reviews were produced in the four subject areas and amply discussed in the group. After emendation, they were presented to the plenary where after further modification, they were accepted. RESULTS: Static computer-aided surgery (s-CAIS), in terms of pain & discomfort, economics and intraoperative complications, is beneficial compared with conventional implant surgery. When using s-CAIS in partially edentulous cases, a higher level of accuracy can be achieved when compared to fully edentulous cases. When using an intraoral scanner in edentulous cases, the results are dependent on the protocol that has been followed. The accuracy of measurements on CBCT scans is software dependent. CONCLUSIONS: Because the precision intraoral scans and of measurements on CBCT scans and is not high enough to allow for the required accuracy, s-CAIS should be considered as an additional tool for comprehensive diagnosis, treatment planning, and surgical procedures. Flapless s-CAIS can lead to implant placement outside of the zone of keratinized mucosa and thus must be executed with utmost care.

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.

Implant treatment in periodontally compromised subjects--quality of life and patient satisfaction.

OBJECTIVES: The aims of this study were to determine the quality of life of periodontally compromised patients after implant treatment (primary aim) and their satisfaction with the restoration and treatment approach (secondary aim). MATERIAL AND METHODS: In this study, 61 adult subjects were evaluated following non-surgical periodontal treatment, under regular maintenance and implant therapy with a fixed restoration. Oral health-related quality of life (OHQoL) was assessed using the German short form of the Oral Health Impact Profile (OHIP-G14). Patient satisfaction with the restoration and treatment procedure was investigated applying a self-designed questionnaire focusing on social-psychological aspects. Statistical analysis of the collected data was performed using Kruskal-Wallis and Man-Whitney U test for the relationship between OHIP score and number of implants, patient age and level of education. RESULTS: The average OHIP-G14 score of the examined study population was 2.78 (SD ±4.2), while the item pain had the biggest influence on the number of points. No statistical significance was detected between the relationship of OHIP-G14 score and the number of placed implants (p = 0.98). Furthermore, there was no statistically significant correlation between OHIP-G14 score and patient age (p = 0.67) or for level of education (p = 0.39). The questionnaire focusing on patient satisfaction showed a high level of contentment in this study population. All patients declared that they would repeat the treatment and most (98.4%) would recommend it to their friends. Furthermore, a high level of satisfaction with aesthetics, stability, cleanability and speech comprehension was reported. CONCLUSION: The examined study population showed a quality of life after implant therapy comparable to pre-existing reference values of a healthy non-restored population. There was no statistical significance between OHIP-G 14 score and the number of implants, patients' age and education level. Analysis of the satisfaction with the realized implant therapy provided consistently positive results. CLINICAL RELEVANCE: When restoring periodontally compromised patients, implant treatment should be considered to achieve potentially higher oral health-related quality of life compared to for example removable dentures. This needs to be investigated in randomized controlled clinical trials.

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.

Prevalence of periodontitis in individuals with human leukocyte antigens (HLA) A9, B15, A2, and B5.

OBJECTIVE: Human leukocyte antigens (HLA) have been associated with periodontitis. Previous studies revealed HLA-A9 and HLA-B15 as potential susceptibility factors, while HLA-A2 and HLA-B5 might have protective effects. The aim of the study was to verify these associations in a group of HLA-typed blood donors with previously unknown periodontal status. MATERIALS AND METHODS: In four German centers, 140 blood donors with known HLA class I status were enrolled and allocated to the following five groups: HLA-A9 (N = 24), HLA-B15 (N = 20), HLA-A2 (N = 30), HLA-B5 (N = 26), and controls (N = 40). Periodontal examination included the measurement of probing depths (PDs), clinical attachment level (CAL), bleeding on probing (BOP), and community periodontal index of treatment needs (CPITN). RESULTS: Carriers with HLA-A9 and HLA-B15 had higher values of mean PD (P < 0.0001), CAL (P < 0.0001), and BOP (P < 0.002) as well as sites with PD and CAL with ≥4 and ≥6 mm (P < 0.0003), respectively, than controls. Multiple regression analyses revealed HLA-A9, HLA-B15, and smoking as risk indicators for moderate to severe (CPITN 3-4; odds ratio (OR): 66.7, 15.3, and 5.1) and severe (CPITN 4; OR: 6.6, 7.4, and 3.8) periodontitis. HLA-A2 and HLA-B5 did not show any relevant associations. CONCLUSION: The present data support a role of HLA-A9 and HLA-B15 as susceptibility factors for periodontitis, whereas HLA-A2 and HLA-B5 could not be confirmed as resistance factors. CLINICAL RELEVANCE: Both HLA antigens A9 and B15 are potential candidates for periodontal risk assessment.

On the relationship between gingival biotypes and gingival thickness in young Caucasians.

OBJECTIVES: To evaluate a possible relationship between gingival biotypes and gingival thickness, papilla height and gingival width. MATERIAL AND METHODS: Thirty-six adult subjects were stratified by their gingival biotype (GB), as defined by transparency of a periodontal probe through the buccal gingival margin, into "thin" (18 subjects) and "thick" (18 subjects) GB. Out of these, extreme cases (6 "very thin", 6 "very thick") were identified. Four different parameters were assessed: gingival thickness (GT), papilla height (PH), probing depth (PD) and gingival width (GW). RESULTS: When comparing "thin" and "thick" GB, midfacial GT (0.40 ± 0.07 vs. 0.72 ± 0.11 mm; P < 0.0001), PH (3.76 ± 0.50 vs. 3.95 ± 0.41 mm, P = 0.02) and GW (3.01 ± 1.26 vs. 4.63 ± 0.86 mm, P = 0.04) were lower in the "thin" GB group. Further stratification into moderately and extremely "thin"/"thick" GB eliminated the differences between the moderate groups. CONCLUSION: Our data support the traditional hypothesis that two different gingival biotypes with concomitant properties distinguishable by gingival transparency exist. In addition, we provide evidence that an alternative classification into "very thick", "moderate" and "very thin" biotypes might be advantageous, because the unique properties were seemingly primarily driven by subjects with extreme values.

Porcine dermal matrix in the treatment of dehiscence-type defects--an experimental split-mouth animal trial.

OBJECTIVES: To describe histometrical outcomes (tissue thickness, tissue height) of a porcine dermal matrix (PDX) and subepithelial connective tissue (CTG) in the treatment of dehiscence-type defects. MATERIAL AND METHODS: In five beagle dogs buccal dehiscence defects were created on both upper canines. The defects were covered in a split-mouth design either with a porcine dermal matrix or subepithelial connective tissue. After 4 months histometrical outcomes were evaluated using a nonparametric Brunner-Langer model. RESULTS: Neither in the test nor in the control specimen signs of inflammation or foreign body reaction was detected. Histometrically, no significant difference was found for tissue thickness and height between both treatment groups. CONCLUSIONS: Porcine dermal matrix can be used for grafting of dehiscence-type defects. Augmentation of tissue thickness seems to be comparable to subepithelial connective tissue.

Influence of local administration of pamidronate on extraction socket healing--a histomorphometric proof-of-principle pre-clinical in vivo evaluation.

OBJECTIVES: To evaluate the influence of local administration of pamidronate histomorphometrically, adsorbed on a collagenated porcine bone substitute, on extraction socket healing. MATERIAL AND METHODS: Two American Fox-hound dogs were used within this proof-of-principle study. Following endodontic treatment of the distal root of the three lower premolars, the teeth were hemisected, and the mesial roots were extracted flapless. The sockets were then loosely filled, in a split-mouth fashion, with a collagenated porcine bone substitute (Osteobiol Gen-Os; CPB), rehydrated either with 90 mg/ml pamidronate (Aredia(®) ; test) or with sterile saline (control). Extraction sockets were sealed with connective tissue punches obtained from the palate and secured with sutures. After 4 months of healing, specimens containing the socket sites and remaining roots were retrieved and histomorphometrically examined. RESULTS: Histological evaluation of the sections revealed substantial differences in healing patterns. Control sites presented with various amounts of newly formed bone and no evidence of CPB inside the socket; in contrast, limited amounts of bone were observed at test sites, which were filled with CPB mainly embedded in connective tissue. Only minor differences were observed between test and control sites regarding vertical bone loss (buccal bone: -1.01 mm vs. -1.15 mm; lingual bone: -0.92 mm vs. -1.15 mm). Horizontal bone loss was nearly three times higher in control sites comparing to sites treated with pamidronate (-2.19 ± 1.81 mm vs. -0.80 ± 0.91 mm) at a level corresponding to 3 mm below the cemento-enamel junction (CEJ). CONCLUSION: Local administration of pamidronate adsorbed on a collagenated porcine bone substitute in particulate form appeared to delay extraction socket healing, but may also reduce post-extraction dimensional changes in terms of horizontal bone width. Additionally, pamidronate appears to obstruct resorption of the porcine bone substitute.

On the relationship between gingival biotypes and supracrestal gingival height, crown form and papilla height.

OBJECTIVES: To determine the association between gingival biotypes and supracrestal gingival height (primary aim) and its relation to crown shape and papilla height (secondary aim). MATERIALS AND METHODS: Eighty adult subjects were evaluated in this study. Based on the transparency of a periodontal probe through the buccal gingival margin, 38 subjects comprised the thin biotype group and 42 subjects comprised the thick biotype group, respectively. Three different parameters were clinically assessed: supracrestal gingival height (SGH) by bone sounding, crown width/crown length ratio and papilla height. RESULTS: No statistical difference (P > 0.05) was detected neither for the correlation between different biotypes (thick/thin) and SGH nor for the association of biotypes and crown width/crown length ratio. Papilla height was only significantly increased (P ≤ 0.05) in the area of teeth no. 21/22 for the thin periodontal biotype. Intra-examiner deviation was found to be very low for all clinical parameters (percentile agreement > 95%). CONCLUSIONS: Within the limits of this study, we found that in young Caucasians (i) soft tissue dimensions seem to be similar between biotypes (ii) and the traditional hypothesis that a thick gingiva merges with broad-short crown shape and flat papillae and a thin gingiva with a narrow-long crown shape and high scalloping, may be questionable.

Early wound healing and patient morbidity after single-incision vs. trap-door graft harvesting from the palate--a clinical study.

OBJECTIVES: The aim of this study is to compare wound healing and patient pain perception of single-incision (single-incision, modified single-incision) and trap-door surgical techniques to harvest subepithelial connective tissue grafts from the palate. MATERIAL AND METHODS: Thirty-six patients were selected for root coverage procedures with subepithelial connective tissue grafts and randomly assigned to two single-incision groups or a trap-door group (n = 12/group). One week after surgery, a modified early-wound healing index (EHI), patient pain and painkiller intake were recorded. Follow-up was performed until complete epithelialization was achieved. RESULTS: Single-incision techniques showed significantly improved early healing over trap-door approaches. Specifically, the mean EHI was 2.50 ± 1.14 for single-incision techniques, as compared to 3.33 ± 1.30 for trap door. The incidence of secondary healing was significantly lower in the single-incision groups. Concomitantly, the cumulative dosage and duration of painkiller intake were significantly reduced, as compared to the trap-door group. CONCLUSION: Within the limits of this trial, single-incision techniques can lead to improved early healing and reduced patient pain after subepithelial connective tissue graft harvesting than trap-door techniques. CLINICAL RELEVANCE: Avoiding trap-door incisions for harvesting of connective tissue grafts may reduce patient morbidity.