Factors influencing outcomes of surgical therapy of peri-implantitis: A secondary analysis of 1-year results from a randomized clinical study.

AIM: To identify predictors of treatment outcomes following surgical therapy of peri-implantitis. MATERIALS AND METHODS: We performed a secondary analysis of data from a randomized controlled trial (RCT) comparing access flap with or without bone replacement graft. Outcomes at 12 months were probing pocket depth (PPD), bleeding on probing (BOP), soft-tissue recession (REC) and marginal bone level (MBL) change. Multilevel regression analyses were used to identify predictors. We also built an explanatory model for residual signs of inflammation. RESULTS: Baseline PPD was the most relevant predictor, showing positive associations with final PPD, REC and MBL gain, and negative association with probability of pocket closure. Smokers presented higher residual PPD. Absence of keratinized mucosa at baseline increased the probability of BOP but was otherwise not indicative of outcomes. Plaque at 6 weeks was detrimental in terms of residual PPD and BOP. Treatment allocation had an effect on REC. Final BOP was explained by residual PPD ≥6 mm and plaque at more than two sites. CONCLUSIONS: Baseline PPD was the most relevant predictor of the outcomes of surgical therapy of peri-implantitis. Pocket closure should be a primary goal of treatment. Bone replacement grafts may be indicated in aesthetically demanding cases to reduce soft-tissue recession. The importance of smoking cessation and patient-performed plaque control is also underlined.

Early bone healing to implants with different surface characteristics. A pre-clinical in vivo study.

AIM: To examine early bone healing around implants with non-modified and modified surfaces. MATERIAL & METHODS: Four implants with 4 different surface characteristics were installed in one side of the mandible following tooth extraction in 6 dogs. Implants in group A had a non-modified, turned surface, while implants in group B had a surface modification consisting of TiO-blasting and sequential acid-etching in oxalic and hydrofluoric acid. The surface modification of implants in group C was confined to sequential acid-etching in oxalic and hydrofluoric acid and Group D implants had a surface modification of TiO-blasting and acid-etching in hydrofluoric acid. The implant installation procedures were repeated in the opposite side of the mandible 4 weeks later. Biopsies were obtained and prepared for histological analysis 2 weeks later. RESULTS: B and C implants had a higher degree of bone-to-implant contact (BIC%) than A and D implants at 2 weeks of healing. At 6 weeks of healing, the BIC% was higher at B than at A, C and D implants, and higher at C implants than at A implants. The amount of newly formed bone in contact with the implant within the defect area at 2 weeks was higher at implants with modified surfaces (groups B, C and D) than at implants with a non-modified surface (group A). Corresponding results at 6 weeks were superior at B implants. CONCLUSION: It is suggested that an implant surface modification with acid-etching in oxalic and hydrofluoric acid promotes early formation of bone-to-implant contact.

Reconstructive surgical therapy of peri-implantitis: A multicenter randomized controlled clinical trial.

OBJECTIVE: To evaluate the potential benefit of the use of a bone substitute material in the reconstructive surgical therapy of peri-implantitis. METHODS: In this multicenter randomized clinical trial, 138 patients (147 implants) with peri-implantitis were treated surgically, randomized by coin toss to either a control (access flap surgery) or a test group (reconstructive surgery using bone substitute material). Clinical assessments, including probing pocket depth (PPD), bleeding and suppuration on probing (BOP & SOP) as well as soft tissue recession (REC), were recorded at baseline, 6 and 12 months. Marginal bone levels (MBL), measured on intra-oral radiographs, and patient-reported outcomes (PROs) were recorded at baseline and 12 months. No blinding to group allocation was performed. The primary outcome at 12 months was a composite measure including (i) implant not lost, (ii) absence of BOP/SOP at all aspects, (iii) PPD ≤5 mm at all aspects and (iv) ≤1 mm recession of mucosal margin on the buccal aspect of the implant. Secondary outcomes included (i) changes of MBL, (ii) changes of PPD, BOP%, and buccal KM, (iii) buccal REC and (iv) patient-reported outcomes. RESULTS: During follow-up, four implants (one in the test group, three in the control group) in four patients were removed due to disease progression. At 12 months, a total of 69 implants in the test and 68 implants in the control group were examined. Thus, 16.4% and 13.5% of implants in the test and control group, respectively, met all predefined criteria of the composite outcome. PPD reduction and MBL gain were 3.7 mm and about 1.0 mm in both groups. Reduction in mean BOP% varied between 45% (test) and 50% (control), without significant differences between groups. Buccal REC was less pronounced in the test group (M = 0.7, SD = 0.9 mm) when compared to controls (M = 1.1, SD = 1.5 mm). PROs were favorable in both groups without significant differences. One case of allergic reaction to the antibiotic therapy was recorded. No other adverse events were noted. CONCLUSIONS: Surgical therapy of peri-implantitis effectively improved the clinical and radiographic status at 12 months. While the use of a bone substitute material did not improve reductions of PPD and BOP, buccal REC was less pronounced in the test group. Patient satisfaction was high in both groups.

Surgical treatment of experimental peri-implantitis using mechanical and chemical decontamination procedures: A pre-clinical in vivo study.

AIM: To evaluate the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using mechanical and chemical decontamination methods. MATERIALS AND METHODS: Following extraction of mandibular premolars, four implants with two different surface characteristics (A, moderately rough and B, smooth) were placed in each side of the mandible of six dogs. Experimental peri-implantitis was induced. Surgical treatment of the peri-implantitis sites was carried out using four implant surface decontamination protocols: (i) deposition of a citric acid gel, (ii) mechanical cleaning using a rotating titanium brush, (iii) a combination of the mechanical and chemical procedures, and (iv) saline (control). Clinical and radiographic examinations were performed. Block biopsies were obtained 6 months after therapy and prepared for histological analysis. RESULTS: Irrespective of the treatment group, treatment resulted in 0.63 ± 0.92 and 0.65 ± 0.67 mm radiographic bone gain around implants A and B, respectively. Histological analyses revealed that persisting soft tissue inflammation as assessed using an infiltrated connective tissue (ICT) score was significantly lower at implant type B than at implant type A for all treatment groups. The test decontamination procedures did not demonstrate better results regarding resolution of peri-implantitis lesions, as indicated by the ICT scores, than the control procedure. The control treatment resulted in significantly superior outcomes of resolution of peri-implantitis lesions than the citric acid regimen. CONCLUSIONS: It is concluded that decontamination procedures including citric acid gel or rotating titanium brush did not improve outcomes following surgical treatment of experimental peri-implantitis. Results were, however, influenced by the implant surface characteristics.

Accuracy of bone-level assessments following reconstructive surgical treatment of experimental peri-implantitis.

AIMS: The purpose of this study was to evaluate the accuracy of bone-level assessments using either cone-beam computed tomography (CBCT), intra-oral peri-apical (PA) radiographs or histology following reconstructive treatment of experimental peri-implantitis. MATERIALS AND METHODS: Six Labrador dogs were used. Experimental peri-implantitis was induced 3 months after implant placement. Surgical treatment of peri-implantitis was performed and peri-implant defects were allocated to one of four treatment categories; no augmentation, bone graft materials with or without a barrier membrane. Six months later, intra-oral PA radiographs and block biopsies from all implants sites were obtained. Marginal bone levels (MBLs) were measured using PA radiographs, CBCT and histology. RESULTS: Significant correlations of MBL assessments were observed between the three methods. The measurements in PA radiographs consistently resulted in an overestimation of the bone level of about 0.3-0.4 mm. The agreement between the methods was not influenced by the use of bone substitute materials in the management of the osseous defects. CONCLUSIONS: Although MBL assessments obtained from PA radiographs showed an overestimation compared to MBL assessments on corresponding CBCT images and histological sections, PA radiographs can be considered a reliable technique for peri-implant bone-level evaluations following reconstructive surgical therapy of experimental peri-implantitis.

A person-centred, theory-based, behavioural intervention programme for improved oral hygiene in adolescents: A randomized clinical field study.

AIM: To test the effectiveness of a person-centred and theory-based educational intervention to increase adolescents' adherence to adequate oral hygiene behaviour, that is, self-performed periodontal infection control. MATERIALS AND METHODS: Data were derived from a prospective, multi-centred, two-arm, quasi-randomized field study in which treatment was performed by dental hygienists (DHs) within the Public Dental Service, Västra Götaland, Sweden. Adolescents with poor oral hygiene conditions were invited to participate. The test intervention was based on cognitive behavioural theory and principles, and the DHs used a collaborative communicative approach, inspired by motivational interviewing. The control intervention consisted of conventional information/instruction. Clinical assessments and oral hygiene behaviours were evaluated at 6 months. RESULTS: Three-hundred and twelve adolescents were enrolled, of whom 274 followed the treatment to 6-month follow-up. There were significant improvements in gingival bleeding and plaque scores for both treatment groups at 6 months, with significantly greater improvements in the test group. Adolescents in the test group brushed their teeth and used interdental cleaning aids more frequently compared to participants in the control group at 6 months. CONCLUSION: A person-centred and theory-based oral health education programme is more effective than conventional oral health education in improving adolescents' oral hygiene behaviour and periodontal infection control. CLINICALTRIALS: gov (NCT02906098).

Influence of implant geometry and osteotomy design on early bone healing: A pre-clinical in vivo study.

OBJECTIVES: To analyze the early stages of osseointegration around implants with different geometry following installation in sites using different osteotomy protocols. MATERIALS AND METHODS: Two types of implants were installed using regular or modified (reduced diameter) osteotomy protocols in mandibular premolar/molar regions following tooth extraction in six dogs. Three implant site categories were created: Reference (A implant and regular osteotomy), Test-1 (B implant and regular osteotomy), and Test-2 (B implant and modified osteotomy). Implant installation procedures were repeated after 4 and 6 weeks. The insertion torque (ITQ) was measured during implant installation and resonance frequency analysis providing implant stability quotient (ISQ) values was performed following implant installation and once every week during the course of the study. Biopsies were obtained immediately after the 3rd installation procedure and prepared for histological analysis. RESULTS: The modified osteotomy protocol created a higher insertion torque (ITQ). The analysis also revealed a correlation between insertion torque at implant installation and radiographic bone loss after 6 weeks of healing. The decline in ISQ values during healing was more pronounced at Test-2 than other sites. While the degree of bone-to-implant contact (BIC%) in the marginal area was similar in test and reference sites at 6 weeks of healing, Test-2 implants presented with a significantly higher BIC% in the mid and apical areas than Test-1 implants. CONCLUSIONS: It is suggested that placement of implants in undersized osteotomy sites will result in an increased remodeling of the cortical bone during the early healing process.

Effect of biofilm formation on implant abutments with an anti-bacterial coating: A pre-clinical in vivo study.

OBJECTIVES: To analyse the long-term effect of plaque formation on implant abutments with an antibacterial coating and the ensuing host response in peri-implant tissues. MATERIALS AND METHODS: Four implants were installed in each mandibular premolar region following tooth extraction in six dogs. Three months later, two test abutments with a titanium-bismuth-gallium (Ti-Bi-Ga) coating and two control titanium abutments were connected to the implants on each side of the mandible. After 2 months, ligatures were placed around the implants in one side of the mandible and plaque formation was allowed until the end of the experiment. The ligatures were removed after 4 weeks. Radiographs and microbiological samples were obtained from each implant site during the plaque formation period. Biopsies were obtained 8 months after abutment connection and prepared for histological analysis. RESULTS: The analysis did not reveal any statistically significant differences in bone loss, bacterial growth and size of inflammatory lesions between implant units with and without the Ti-Bi-Ga coating. Implant sites exposed to the short period of ligature-induced breakdown demonstrated more pronounced bone loss and bacterial growth than non-ligature sites. CONCLUSIONS: It is suggested that a Ti-Bi-Ga coating does not prevent biofilm formation on the implant device and does not influence the ensuing host response in the adjacent peri-implant mucosa.

Comparison of 6-mm and 11-mm dental implants in the posterior region supporting fixed dental prostheses: 5-year results of an open multicenter randomized controlled trial.

OBJECTIVE: The aim of this multicenter, randomized controlled trial was to compare the clinical and radiographic outcomes of 6-mm or 11-mm implants, placed in the posterior maxilla and mandible, during a 5-year follow-up period. MATERIALS AND METHODS: Ninety-five patients with adequate bone height for 11-mm implants, were randomly allocated to a 6-mm group (test group with short implants) or an 11-mm group (control group with standard-length implants). Two or three implants of the same length were placed in each patient and after 6 weeks loaded with a splinted provisional restoration. This was followed by definitive splinted restoration 6 months after implant placement. Clinical and radiographic parameters, including the occurrence of complications were recorded. RESULTS: A total of 49 patients were enrolled to receive 6-mm implants (n = 108) and 46 patients to receive 11-mm implants (n = 101). Three implants (two of 6 mm and one of 11 mm in length) were lost before loading and one 6-mm implant after 15 months of function, and one 11-mm implant was lost during the first year of function. The 5-year survival rates were 96.0% and 98.9% in the 6-mm and 11-mm group, respectively. The mean marginal bone level changes 5 years post-loading were 0.01 ± 0.45 mm (bone gain) in the 6-mm group and -0.12 ± 0.93 mm (bone loss) in the 11-mm group (p = .7670). Clinical parameters, including plaque, bleeding on probing and pocket probing depth were not significantly different between the groups, and also technical complications were low. CONCLUSION: The clinical and radiographic outcomes of 6-mm short and 11-mm standard-length implants were not different during a 5-year evaluation period.

Risk for recurrence of disease following surgical therapy of peri-implantitis-A prospective longitudinal study.

OBJECTIVES: The aim of the present prospective study was to assess the risk for disease recurrence following surgical therapy of peri-implantitis. MATERIAL & METHODS: 73 patients (130 implants) treated surgically for peri-implantitis were examined at 1 and 5 years after therapy. The primary outcome was recurrence/progression of disease defined as any of the following events: (a) bone loss >1.0 mm, (b) surgical retreatment, (c) implant removal/loss after year 1. Patient- and implant-related parameters as well as 1-year outcomes were evaluated as potential predictors through multiple logistic regression analysis. RESULTS: 57 implants (44%) displayed recurrence/progression of peri-implantitis during follow-up. Among these, 27 implants were removed. Residual deep probing pocket depth (≥6 mm; odds ratio 7.4; 95% confidence interval 2.8-19.3) and reduced marginal bone level (OR 1.4; 95%CI 1.1-1.7) at 1 year after surgery constituted risk factors for recurrence/progression of disease. Furthermore, implants with modified surfaces were at higher risk than implants with non-modified surfaces (OR 5.1; 95%CI 1.6-16.5). CONCLUSION: Implants with (a) residual deep probing pocket depth, (b) reduced marginal bone level, or (c) modified surfaces following surgical therapy of peri-implantitis present with increased risk for recurrence/progression.

Spontaneous progression of experimental peri-implantitis in augmented and pristine bone: A pre-clinical in vivo study.

OBJECTIVE: To examine the progression of experimental peri-implantitis around different implants placed in augmented and pristine sites. MATERIALS AND METHODS: Six labrador dogs were used. Three months after tooth extraction, four implants with different surface modifications were installed on each side of the mandible. A standard osteotomy was applied on one side, while on the contralateral side the osteotomy was modified, resulting in a gap between the implant and the bone wall. The gap was filled with a bone substitute and covered by a resorbable membrane. Three months after implant installation, implants were exposed and healing abutments were connected. Two months later, oral hygiene procedures were abandoned and a cotton ligature was placed in a submarginal position around the neck of all implants and kept in place for 4 weeks. Following ligature removal, plaque formation continued for 6 months (spontaneous progression period). Radiographs were obtained throughout the experiment, and biopsies were collected and prepared for histological evaluation at the end of the spontaneous progression period. RESULTS: Differences in bone loss during the spontaneous progression period between pristine and augmented sites were small. The size and vertical dimension of the peri-implantitis lesion were larger at augmented than at pristine sites. Implants with non-modified surfaces exhibited smaller amounts of bone loss and smaller dimensions of peri-implantitis lesions than implants with modified surfaces. CONCLUSION: Small differences in spontaneous progression of peri-implantitis were detected between pristine and augmented sites. Implants with modified surfaces exhibited more bone loss and larger lesions than implants with non-modified surfaces, irrespective of the type of surrounding bone.

Re-osseointegration following reconstructive surgical therapy of experimental peri-implantitis. A pre-clinical in vivo study.

OBJECTIVE: To evaluate the effect of bone substitute materials on hard and soft tissue healing in reconstructive surgical therapy of experimental peri-implantitis at implants with different surface characteristics. MATERIAL AND METHODS: Six female, Labrador dogs were used. 3 months after tooth extraction, four implants with two different surface characteristics (A and B) were installed on each side of the mandible. Experimental peri-implantitis was induced 3 months later. During surgical treatment of peri-implantitis, the implants were cleaned with curettes and cotton pellets soaked in saline. The implant sites were allocated to one of four treatment categories; (a) Group C; no augmentation, (b) Group T1; bone defect filled with deproteinized bovine bone mineral (c) Group T2; bone defect filled with a biphasic bone graft material, (d) Group T3; bone defect filled as T1 and covered with a collagen membrane. Clinical and radiological examinations were performed, and biopsies were obtained and prepared for histological analysis 6 months after peri-implantitis surgery. RESULTS: Implant B (smooth surface) sites showed significantly (a) larger radiographic bone level gain, (b) enhanced resolution of peri-implantitis lesions, and (c) larger frequency of re-osseointegration than implant A (moderately rough surface) sites. Implant B sites also showed superior preservation of the mucosal margin. Differences between bone substitute materials and control procedures were overall small with limited advantages for T1 and T2 sites. CONCLUSION: Healing following reconstructive surgical treatment of experimental peri-implantitis was superior around implants with a smooth surface than implants with a moderately rough surface. Benefits of using bone substitute materials during surgical therapy were overall small.

Peri-implant tissue healing at implants with different designs and placement protocols: An experimental study in dogs.

OBJECTIVES: To compare the peri-implant tissue response to subcrestal or crestal placement of implants with or without "platform-switched" implant/abutment connections. MATERIAL AND METHODS: On each side of the mandible in six Labrador dogs, two "platform-switched" (PS) implants and two implants with matching implant/abutment diameters (PM) were placed in a crestal or a 1.5 mm subcrestal position. Sulcus formers/abutments were connected, baseline radiographs obtained and the distance between the abutment-fixture junction (A/F) and the marginal bone level (B) was determined. Five months later, radiographic and clinical examinations were repeated and biopsies were obtained and processed for histological analysis. RESULTS: The radiographic analysis showed that marginal bone level changes occurred during the first observation period (13 weeks). PS-implants showed minor marginal bone level alterations during the full observation period (20 weeks), regardless of placement depth. For PM-implants, placement had a significant impact on bone level changes; crestal placement resulted in a mean bone loss of 0.4 mm and subcrestal placement in a 1.5 mm bone loss. The histometric measurements resulted in a distance A/F-B of 0.6 and 0.0 mm for PS implants, placed in a crestal or subcrestal position, respectively. The corresponding distance at PM-implants was 1.5 mm irrespective of placement protocol. The peri-implant mucosa was thicker at subcrestally placed implants as compared to a crestal placement. CONCLUSIONS: Bone remodeling occurred within the early healing phase. During the full 20 weeks of observation, PS-implants demonstrated significantly less crestal bone loss compared to PM-implants.

Periodontal disease among older people and its impact on oral health-related quality of life.

OBJECTIVE: The aim of the study was to evaluate the associations between degree of periodontal disease and number of teeth on oral health-related quality of life among older individuals. MATERIAL AND METHODS: Randomly selected 804 participants aged ≥70 derived from two cohorts were included in the analysis. Dental examinations and evaluation of OHRQL using the OHIP-14 (Oral Health Impact Profile-14) were performed. After categorisation of the participants according to the extent of periodontitis in three groups (none, localised with <30% of teeth affected, generalised with ≥30% of teeth affected) and the number of teeth, associations between periodontal status and the number of teeth and the OHIP-14 scores were analysed. Multivariable regression analyses were used taking into account level of periodontitis, number of teeth, age and sex. RESULTS: Among 70-year-old men and women, generalised periodontitis showed an association with poor OHRQL. However, a multivariable analysis failed to demonstrate this association (OR = 1.02, 95% CI: 0.72-1.44). In participants with 1-10 remaining teeth, the OHIP-14 score was significantly increased indicating poor OHRQL, compared with participants with ≥21 remaining teeth (OR = 1.57, 95% CI: 1.13-2.19). Similar findings were observed among women aged 70-92 years. CONCLUSIONS: Periodontitis did not show an association with poor OHRQL, however, a significant association between the number of teeth and poor OHRQL was found.

Marginal bone level and survival of short and standard-length implants after 3 years: An Open Multi-Center Randomized Controlled Clinical Trial.

OBJECTIVES: The present multi-center randomized controlled clinical trial sought to compare the marginal bone level (MBL) changes and survival of 6- and 11-mm implants. MATERIAL AND METHODS: Ninety-five patients receiving a total of 209 dental implants were enrolled. Subjects were randomly allocated to two cohorts: test (4.0 × 6 mm; N = 108) or control (4.0 × 11 mm; N = 101) implant groups. To be randomized, all edentulous sites were anatomically qualified to receive 11 mm implant. Two to three implants were placed in maxillary or mandibular posterior regions and loaded with splinted provisional restoration after 6 weeks and definitive restoration 6 months thereafter. Test and control implants were followed by clinical and radiographic examinations on an annual basis up to 3 years. RESULTS: Radiographic assessment of MBL 3 years after loading revealed the bone to be located at 0.27 mm (±0.40) and 0.44 mm (±0.74) apical to the implant platform in the test and control groups, respectively. During the 3 years of follow-up since loading, 0.04 mm (±0.43) MBL gain and 0.02 mm (±0.76) of MBL loss were observed in the 6-mm (test) and 11-mm (control) groups, respectively. The MBL's for test and control were significantly different (p = 0.000) in favor of short implants. The cumulative survival rates from placement after 3 years were 96% and 99% for the 6- and 11-mm implants, respectively, with no statistical significance. CONCLUSIONS: Reconstruction of partially edentulous posterior maxilla or mandible with 6- or 11-mm implants led to stable marginal bone level and high implant survival rate after 3 years.

Surgical treatment of peri-implantitis: 3-year results from a randomized controlled clinical trial.

OBJECTIVES: This study reports on the 3-year follow-up of patients enrolled in a randomized controlled clinical trial on surgical treatment of advanced peri-implantitis. MATERIAL AND METHODS: A total of 100 patients with advanced peri-implantitis were randomly assigned to one of four treatment groups. Surgical therapy aiming at pocket elimination was performed and, in three test groups, supplemented by either systemic antibiotics, use of an antiseptic agent for implant surface decontamination or both. Outcomes were evaluated after 1 and 3 years by means of clinical and radiological examinations. Differences between groups were explored by regression analysis. RESULTS: Clinical examinations at 3 years after treatment revealed (i) improved peri-implant soft tissue health with a mean reduction in probing depth of 2.7 mm and a reduction in bleeding/suppuration on probing of 40% and (ii) stable peri-implant marginal bone levels (mean bone loss during follow-up: 0.04 mm). Implant surface characteristics had a significant impact on 3-year outcomes, in favour of implants with non-modified surfaces. Benefits of systemic antibiotics were limited to implants with modified surfaces and to the first year of follow-up. CONCLUSION: It is suggested that surgical treatment of peri-implantitis is effective and that outcomes of therapy are affected by implant surface characteristics. Potential benefits of systemic antibiotics are not sustained over 3 years.

Altered expectations on dental implant therapy; views of patients referred for treatment of peri-implantitis.

AIM: The aim was to explore patients' reactions on being diagnosed with peri-implantitis, their opinions on dental implant therapy and expectations on treatment of the disease. MATERIAL AND METHODS: The study subjects were patients referred to a specialist clinic for treatment of peri-implantitis. The method of grounded theory was used in collecting and analyzing data. Audiotaped, thematized open-ended interviews were conducted. The interviews were transcribed verbatim and consecutively analyzed in hierarchical coding processes that continued until saturation was met (n = 15). RESULTS: In the analysis, a conceptual model was generated that illuminated a process among patients. From having very high initial expectations on dental implant therapy as a permanent solution of oral/dental problems, patients realized that dental implants, such as teeth, require continuous care and that there is no guarantee for that dental implants provides a treatment alternative free from future problems. The core concept of the model "altered expectations on dental implant therapy" was composed of three main categories: "initial expectations on dental implant therapy and living with dental implants", "being referred to periodontist and become diagnosed with peri-implantitis" and "investing again in an expensive therapy with no guarantee for the future". CONCLUSION: Patients may have unrealistically high expectations on dental implant therapy. The results illuminate the importance of patient-centered communication in dentistry and that treatment decisions should be based not only on professional expertise but also on expectations, abilities, wishes and life circumstances of the individual patient.

Three-Dimensional buccal bone anatomy and aesthetic outcome of single dental implants replacing maxillary incisors.

OBJECTIVES: This case series investigated by means of CBCT, buccal bone three-dimensional anatomy at delayed, two-stage implants in the maxillary incisal tooth region. Moreover, the relation between buccal bone anatomy and soft tissue aesthetics was assessed. MATERIAL AND METHODS: Twelve implants were analysed after on average 8.9 years in function. Baseline and re-evaluation photographs were assessed using the pink aesthetic score (PES). Marginal bone changes were measured from intraoral X-rays. The buccal bone volume associated with the implant and the implant surface not covered by visible buccal bone was computed on CBCT data sets. Buccal bone thickness and level were assessed, as well as the thickness of the crest distally and mesially of the implant. Changes in soft tissue forms and correlation between aesthetics and bone anatomy were calculated by nonparametric statistics. RESULTS: Buccal bone level was located 3.8 mm apical of the implant shoulder, and none of the implants had complete bone coverage. Buccal bone volume was 144.3 mm(3) , and 4.29 mm(3) in the more coronal 2 mm portion. PES did not differ at re-evaluation (9.7) and baseline (9.2). PES was directly correlated with crestal thickness mesially and distally of the implant shoulder. No other significant correlations were observed between bone anatomy and PES or buccal peri-implant health. Marginal bone gain over time was associated with greater coronal bone volume buccally and with greater buccal and marginal bone thickness, while loss was related to less or no bone. CONCLUSIONS: Within present limitations, acceptable and stable aesthetics are not jeopardized by a thin or missing buccal bone.

Temporal sequence of hard and soft tissue healing around titanium dental implants.

The objective of the present review was to summarize the evidence available on the temporal sequence of hard and soft tissue healing around titanium dental implants in animal models and in humans. A search was undertaken to find animal and human studies reporting on the temporal dynamics of hard and soft tissue integration of titanium dental implants. Moreover, the influence of implant surface roughness and chemistry on the molecular mechanisms associated with osseointegration was also investigated. The findings indicated that the integration of titanium dental implants into hard and soft tissue represents the result of a complex cascade of biological events initiated by the surgical intervention. Implant placement into alveolar bone induces a cascade of healing events starting with clot formation and continuing with the maturation of bone in contact with the implant surface. From a genetic point of view, osseointegration is associated with a decrease in inflammation and an increase in osteogenesis-, angiogenesis- and neurogenesis-associated gene expression during the early stages of wound healing. The attachment and maturation of the soft tissue complex (i.e. epithelium and connective tissue) to implants becomes established 6-8 weeks following surgery. Based on the findings of the present review it can be concluded that improved understanding of the mechanisms associated with osseointegration will provide leads and targets for strategies aimed at enhancing the clinical performance of titanium dental implants.

The effect of the local use of chlorhexidine in surgical treatment of experimental peri-implantitis in dogs.

AIM: To evaluate the effect of surgical treatment of experimental peri-implantitis at implants with different surface characteristics using different anti-infective procedures. MATERIAL AND METHODS: Four implants with different surface characteristics (A: TiOblast, B: OsseoSpeed, C: AT-I, D: TiUnite) were installed in a randomized order in each side of the mandible in 6 labrador dogs 3 months after tooth extraction. Experimental peri-implantitis was induced 3 months later. Surgical treatment of peri-implantitis was performed. The implants were cleaned with gauze soaked in either saline (control) or chlorhexidine (test). Clinical and radiographical examinations were performed and microbiological samples were taken during a 6-month period after surgery. Biopsies were obtained and prepared for histological analysis. RESULTS: Clinical signs of soft tissue inflammation were reduced after surgical therapy in most test and control sites. While the analysis of bone level alterations in radiographs together with histological and microbiological assessments of resolution of peri-implantitis lesions failed to demonstrate statistically significant differences between test and control procedures, the evaluations disclosed significant differences between implant D and implants A, B and C on treatment outcome. CONCLUSION: It is suggested that (i) the local use of chlorhexidine has minor influence on treatment outcome, (ii) resolution of peri-implantitis following surgical treatment without the adjunctive use of local and systemic antimicrobial agents is possible and (iii) the results are influenced by implant surface characteristics.