Effects of hyperbaric oxygen therapy on the treatment of severe cases of periodontitis.

OBJECTIVES: To evaluate the effect of hyperbaric oxygen therapy (HBO2) as an adjunct to scaling and root planing (SRP) in the treatment of severe cases of chronic periodontitis. MATERIALS AND METHODS: In 20 patients diagnosed with severe generalized chronic periodontitis (pockets>7mm) with bleeding on probing, SRP was rendered in all pockets. Additionally, five consecutive hyperbaric sessions were administered in 10 patients after random allocation (SRP + HBO2). Clinical parameters were assessed at baseline up to six months: plaque index, bleeding on probing, probing depth, clinical attachment level and benzoyl-DL-arginine-naphthylamide (BANA) test. RESULTS: SRP + HBO2 resulted in greater probing reduction and attachment gain than SRP alone three months after treatment (p<0.001). The BANA test was negative after one week only for sites in the SRP + HBO2 group (p<0.05). However, SRP + HBO2 failed to show a significant difference from SRP group after 3 months, where all BANA sites became negative (p>0.05). CONCLUSION: Our data suggest that hyperbaric oxygen therapy had a short-term beneficial effect on pocket reduction and bacterial elimination, and may be considered a potential adjunct therapeutic option to improve the clinical outcomes of scaling in severe cases of chronic periodontitis.

Cannabis sativa smoke inhalation decreases bone filling around titanium implants: a histomorphometric study in rats.

PURPOSE: Although the harmful effect of tobacco smoking on titanium implants has been documented, no studies have investigated the effects of cannabis sativa (marijuana) smoking. Thus, this study investigated whether marijuana smoke influences bone healing around titanium implants. MATERIALS: Thirty Wistar rats were used. After anesthesia, the tibiae surface was exposed and 1 screw-shaped titanium implant was placed bilaterally. The animals were randomly assigned to one of the following groups: control (n = 15) and marijuana smoke inhalation (MSI) 8 min/d (n = 15). Urine samples were obtained to detect the presence of tetra-hidro-cannabinoid. After 60 days, the animals were killed. The degree of bone-to-implant contact and the bone area within the limits of the threads of the implant were measured in the cortical (zone A) and cancellous bone (zone B). RESULTS: Tetra-hidro-cannabinoid in urine was positive only for the rats of MSI group. Intergroup analysis did not indicate differences in zone A-cortical bone (P > 0.01), however, a negative effect of marijuana smoke (MSI group) was observed in zone B-cancellous bone for bone-to-implant contact and bone area (Student's t test, P < 0.01) values. CONCLUSIONS: Considering the limitations of the present study, the deleterious impact of cannabis sativa smoke on bone healing may represent a new concern for implant success/failure.

The use of flowable composites as filled adhesives.

OBJECTIVE: The effect of filled adhesives on bonding resin composites to dentin has not been fully understood. Due to their filler content, filled adhesives may act as stress breakers. The aim of this in vitro study was to evaluate the use of flowable composites of different viscosities on bonding to enamel and dentin without the use of an intermediate bonding resin. MATERIALS AND METHODS: Enamel and dentin bond strengths of OptiBond FL, Syntac Classic, and EBS Multi combined either with their proprietary bonding agent or a flowable resin composite (Ultraseal XT Plus or Revolution) were measured. The tests were carried out with a microtensile device at a crosshead speed of 1mm/min after 24h of storage at 37 degrees C in water. Mean bond strengths were analyzed using the Wilcoxon test and multiple comparisons according to the Mann-Whitney U-test. The micro-morphology of corresponding resin-dentin interfaces of the same teeth were analyzed using SEM and TEM. RESULTS: The control groups with adhesive systems used as per manufacturers' protocol showed bond strengths of 38.9-41.1 MPa to enamel and 28.8-33.4 MPa to dentin. With respect to bond strength to etched enamel, only Ultraseal XT Plus as bonding resin reached the level of the control groups. When used as bonding agents on dentin, both flowable composites produced lower microtensile bond strengths to etched and primed dentin than did the control groups. Micro-morphological analysis using SEM and TEM resulted in hybrid layer formation for both control and experimental groups. However, many areas of the resin-dentin interface showed insufficient penetration of the flowable composites at the top of the hybrid layer as well as numerous tubules obstructed by filler particles. CONCLUSIONS: The flowable composites tested in this study should not be used to replace bonding agents. Flowable composites of thinner viscosity, such as Ultraseal XT Plus, may bond to enamel adequately without the requirement of an intermediate bonding resin.

Impact of cannabis sativa (marijuana) smoke on alveolar bone loss: a histometric study in rats.

BACKGROUND: Cannabis sativa (marijuana) can interfere with bone physiopathology because of its effect on osteoblast and osteoclast activity. However, its impact on periodontal tissues is still controversial. The present study evaluates whether marijuana smoke affects bone loss (BL) on ligature-induced periodontitis in rats. METHODS: Thirty male Wistar rats were used in the study. A ligature was placed around one of the mandible first molars (ligated teeth) of each animal, and they were then randomly assigned to one of two groups: control (n = 15) or marijuana smoke inhalation ([MSI] for 8 minutes per day; n = 15). Urine samples were obtained to detect the presence of tetrahydrocannabinol. After 30 days, the animals were sacrificed and decalcified sections of the furcation area were obtained and evaluated according to the following histometric parameters: bone area (BA), bone density (BD), and BL. RESULTS: Tetrahydrocannabinol was positive in urine samples only for the rats of the MSI group. Non-significant differences were observed for unligated teeth from both groups regarding BL, BA, and BD (P >0.05). However, intragroup analysis showed that all ligated teeth presented BL and a lower BA and BD compared to unligated teeth (P <0.05). The intergroup evaluation of the ligated teeth showed that the MSI group presented higher BL and lower BD (P <0.05) compared to ligated teeth from the control group. CONCLUSION: Considering the limitations of this animal study, cannabis smoke may impact alveolar bone by increasing BL resulting from ligature-induced periodontitis.