Repeated delivery of chlorhexidine chips for the treatment of peri-implantitis: A multicenter, randomized, comparative clinical trial.

BACKGROUND: Peri-implantitis is a challenging condition to manage and is frequently treated using non-surgical debridement. The local delivery of antimicrobial agents has demonstrated benefit in mild to moderate cases of peri-implantitis. This study compared the safety and efficacy of chlorhexidine gluconate 2.5 mg chip (CHX chips) as an adjunctive treatment to subgingival debridement in patients afflicted with peri-implantitis. METHODS: A multicenter, randomized, single-blind, two-arm, parallel Phase-3 study was conducted. Peri-implantitis patients with implant pocket depths (IPD) of 5-8 mm underwent subgingival implant surface debridement followed by repeated bi-weekly supragingival plaque removal and chlorhexidine chips application (ChxC group) for 12 weeks, or similar therapy but without application of ChxC (control group). All patients were followed for 24 weeks. Plaque and gingival indices were measured at every visit whereas IPD, recession, and bleeding on probing were assessed at 8, 12, 16, 24 week. RESULTS: A total of 290 patients were included: 146 in the ChxC group and 144 in the control. At 24 weeks, a significant reduction in IPD (P = 0.01) was measured in the ChxC group (1.76 ± 1.13 mm) compared with the control group (1.54 ± 1.13 mm). IPD reduction of ≥2 mm was found in 59% and 47.2% of the implants in the ChxC and control groups, respectively (P = 0.03). Changes in gingival recession (0.29 ± 0.68 mm versus 0.15 ± 0.55 mm, P = 0.015) and relative attachment gain (1.47 ± 1.32 mm and 1.39 ± 1.27 mm, P = 0.0017) were significantly larger in the ChxC group. Patients in the ChxC group that were < 65 years exhibited significantly better responses (P < 0.02); likewise, non-smokers had similarly better response (P < 0.02). Both protocols were well tolerated, and no severe treatment-related adverse events were recorded throughout the study. CONCLUSIONS: Patients with peri-implantitis that were treated with an intensive treatment protocol of bi-weekly supragingival plaque removal and local application of chlorhexidine chips had greater mean IPD reduction and greater percentile of sites with IPD reduction of ≥2 mm as compared with bi-weekly supra-gingival plaque removal.

Blood flow changes using a 3D xenogeneic collagen matrix or a subepithelial connective tissue graft for root coverage procedures: a pilot study.

BACKGROUND: The study investigated the early healing process following the treatment of single Miller class I and II recessions with a 3D xenogeneic collagen matrix (CMX) or connective tissue graft (CTG). METHODS: This pilot investigation was designed as a single-center randomized controlled parallel trial. A total of eight subjects (four per group) were treated with either CMX or CTG in the anterior maxilla. Vascular flow changes were assessed by laser Doppler flowmetry (LDF) before and after surgery and at days 1, 2, 3, 7, 14, and 30 while clinical evaluations took place at baseline and at days 60 and 180. Pain intensity perception was evaluated by the short-form McGill pain questionnaire (SF-MPQ), at days 1 and 14. RESULTS: The vascular flow fluctuated similarly in both groups pre- and post-operatively, but the CTG exhibited a more homogeneous pattern as opposed to CMX that showed a second phase of increased blood flow at 14 days. Clinically, the CTG led to greater change in mean root coverage and keratinized tissue gain but CMX was associated with lower early pain intensity scores. CONCLUSIONS: Within the limits of the study, the vascular flow alterations during the early healing of both graft types followed a similar pattern. The CMX was associated with a second peak of increased blood flow. CLINICAL RELEVANCE: The vascular flow changes after the application of CMX for single tooth recession root coverage did not show major differences from those observed after the use of a CTG. A trend for better clinical performance in terms of root coverage and keratinized tissue gain was noted for the CTG, but the initial patient morbidity was less for CMX.

Clinical, microbiological, and salivary biomarker profiles of dental implant patients with type 2 diabetes.

OBJECTIVE: Regulators of peri-implant bone loss in patients with diabetes appear to involve multiple risk factors that have not been clearly elucidated. This study was conducted to explore putative local etiologic factors on implant bone loss in relation to type 2 diabetes mellitus, including clinical, microbial, salivary biomarker, and psychosocial factors. MATERIALS AND METHODS: Thirty-two subjects (divided into type 2 diabetes mellitus and non-diabetic controls), having at least one functional implant and six teeth, were enrolled in a 1-year longitudinal investigation. Analyses of clinical measurements and standardized intra-oral radiographs, saliva and serum biomarkers (via protein arrays for 20 selected markers), and plaque biofilm (via qPCR for eight periodontal pathogens) were performed at baseline and 1 year. In addition, the subjects were asked to respond to questionnaires to assess behavioral and psychosocial variables. RESULTS: There was a significant increase from baseline to 1 year in the probing depth of implants in the diabetes group (1.95 mm to 2.35 mm, P = 0.015). The average radiographic bone loss during the study period marginally increased at dental implants compared to natural teeth over the study period (0.08 mm vs. 0.05 mm; P = 0.043). The control group harbored higher levels of Treponema denticola at their teeth at baseline (P = 0.046), and the levels of the pathogen increased significantly over time around the implants of the same group (P = 0.003). Salivary osteoprotegerin (OPG) levels were higher in the diabetes group than the control group at baseline only; in addition, the salivary levels of IL-4, IL-10, and OPG associated with host defense were significantly reduced in the diabetes group (P = 0.010, P = 0.019, and P = 0.024), while controls showed an increase in the salivary OPG levels (P = 0.005). For psychosocial factors, there were not many significant changes over the observation period, except for some findings related to coping behaviors at baseline. CONCLUSIONS: The study suggests that the clinical, microbiological, salivary biomarker, and psychosocial profiles of dental implant patients with type 2 diabetes who are under good metabolic control and regular maintenance care are very similar to those of non-diabetic individuals. Future studies are warranted to validate the findings in longer-term and larger clinical trials (ClinicalTrials.gov # NCT00933491).

Clinical review: Association between metabolic syndrome and periodontitis: a systematic review and meta-analysis.

BACKGROUND: Several epidemiological studies have reported an association between metabolic syndrome (MetS) and periodontal diseases (PDs). The aim of this systematic review was to investigate the existence and magnitude of this association. MATERIALS AND METHODS: A systematic search of the literature was conducted looking for case-control, cross-sectional, cohort studies and population surveys including patients with measures of MetS and PD. Ovid MEDLINE, EMBASE, LILACS, and Cochrane library databases were used for the search by 2 independent reviewers. A meta-analysis was conducted to investigate the association for coexistence of MetS and PD. RESULTS: A total of 20 studies were included in the review, from an initial search of 3486 titles. Only 1 study reported longitudinal data on the onset of MetS components in association with periodontal measures. However, several studies investigated coexistence. A random effects meta-analysis showed that the presence of MetS is associated with the presence of periodontitis in a total of 36 337 subjects (odds ratio = 1.71; 95% confidence interval = 1.42 to 2.03). When only studies with "secure" diagnoses were included (n = 16 405), the magnitude of association increased (odds ratio = 2.09; 95% confidence interval = 1.28 to 3.44). Moderate heterogeneity was detected (I(2) = 53.6%; P = .004). CONCLUSIONS: This review presents clear evidence for an association between MetS and periodontitis. The direction of the association and factors influencing it should be investigated by longitudinal and treatment studies. Periodontal diagnostic procedures should be routinely carried out in MetS patients.

Early implant bone loss: preventable or inevitable?

Early implant bone loss (EIBL) is defined as the periimplant crestal bone loss occurring from fixture installation to 1 year after loading. This phenomenon has been suggested to be associated with biologic and biomechanical factors. Minimizing EIBL at every treatment step is preferable because this may improve implant health, aesthetics, and overall success. This review presents the host-related factors, implant design characteristics, and the surgical and restorative protocol modifiers that should be evaluated during therapy. Host-related factors may involve the healing capacity, periodontal status, and occlusal function. Implant design features to be considered include the control of biologic width, microgap, and crestal stress distribution. Finally, surgical and restorative factors to be considered are implant site development, minimally invasive surgical approach, implant positioning, and the restorative design and occlusal scheme. Rationale and strategies to control the modifiable factors are also proposed.

Tissue biotype and its relation to the underlying bone morphology.

BACKGROUND: Tissue biotypes have been linked to the outcomes of periodontal and implant therapy. The purpose of this study is to determine the dimensions of the gingiva and underlying alveolar bone in the maxillary anterior region and to establish their association. METHODS: Tissue biotypes of 22 fresh cadaver heads were assessed clinically and radiographically with cone-beam computed tomography (CBCT) scans. Maxillary anterior teeth were atraumatically extracted. The thickness of both soft tissue and bone were measured using a caliper to the nearest 0.1 mm by two calibrated examiners. Probing depths and gingival recession were measured at two points (mid-labial and mid-palatal). Clinical and CBCT measurements of both soft tissue and bone thickness were subsequently compared and correlated. RESULTS: No statistically significant differences were observed between the clinical and CBCT measurements of both soft tissue and bone thickness except the palatal soft tissue measurements. The labial gingival thickness was moderately associated with the underlying bone thickness measured with CBCT (R = 0.429; P <0.05). Gingival recession was not associated with the thickness of both labial gingiva and bone. CONCLUSIONS: CBCT measurements were an accurate representation of the clinical thickness of both labial gingiva and bone. In addition, the thickness of the labial gingiva had a moderate association with the underlying bone radiographically.

The significance of the lingual nerve during periodontal/implant surgery.

BACKGROUND: Understanding the position of the lingual nerve is important when performing third molar extractions and periodontal and implant surgeries in the mandible. The careless management of the lingual flap can potentially cause damage to the lingual nerve. The location of the lingual nerve in the third molar region was described in the literature; however, to our knowledge, its course mesial to the third molar region was not reported. The aim of this study is to identify and measure the location of lingual nerves in relation to mandibular teeth in fresh cadaver heads. METHODS: Thirty lingual nerves from 18 cadaver heads were dissected, and the vertical distance from the lingual nerve to the mid-lingual cemento-enamel junctions of mandibular molars and premolars and the position where the lingual nerve left the lingual plate and moved toward the tongue were determined. Two cadaver heads were randomly selected and exposed to cone-beam computed tomography (CBCT) scans after the insertion of a wrought wire into the nerve. The same vertical distance as the clinical measurement was determined and compared. RESULTS: Seventy-five percent of lingual nerves turned toward the tongue at the first and second molar region. The vertical distance was 9.6, 13, and 14.8 mm at the second molar, first molar, and second premolar, respectively. The difference between clinical and CBCT measurements was 0.57 +/- 2.62 mm. CONCLUSIONS: The course of the lingual nerve in relation to posterior teeth was described. This information can help surgeons gain more understanding of the location of the lingual nerve and perform safe surgeries in the mandible.