1. Female adult rats were subjected to sympathetic denervation of the parotid glands by bilateral... more 1. Female adult rats were subjected to sympathetic denervation of the parotid glands by bilateral removal of the superior cervical ganglion 10-12 days before acute experiments. The sympathectomy was in some of the experimental groups combined with either bilateral adrenal medullectomy, treatment with the sensory neurotoxin capsaicin or parasympathetic denervation of the gland by cutting the auriculotemporal nerve. 2. Food but not water was withheld for 29-32 h before acute experiments. All animals were given an intraperitoneal injection of phentolamine (2 mg kg-1) and propranolol (1 mg kg-1) and, when appropriate, also atropine (1 mg kg-1). Then the experimental animals were fed their ordinary food of hard chow for 60-90 min. Thereafter, these animals and their non-fed controls were killed, and the parotid glands were removed and used for either morphometric assessment or measurement of amylase activity. 3. In the atropinized rats subjected to sympathectomy alone, eating reduced the numerical density of acinar secretory granules by 50% and the total activity of amylase by 55%; the corresponding figures were, when sympathectomy was combined with adrenal medullectomy, 51 and 63%. Also, in atropinized animals subjected to sympathectomy and capsaicin pretreatment, eating reduced the numerical density of acinar granules and the total amylase activity, in this case by 45 and 35%, respectively. 4. In the atropinized rats subjected to sympathectomy and parasympathectomy, eating caused no change in the numerical density of acinar granules but reduced the total amylase activity by 35%. 5. In the non-atropinized rats subjected to sympathectomy alone, eating reduced the numerical density of acinar granules by 22%, while there was no change in the total amylase activity. 6. In conclusion, eating evoked a reflex activation of the sympathectomized parotid gland that engaged non-adrenergic non-cholinergic receptors of the acinar cells. The present results give weight to a physiological role for non-adrenergic non-cholinergic parasympathetic mechanisms in salivary secretion under reflex conditions.
Clinical Implant Dentistry and Related Research, Jan 24, 2022
BackgroundThe growing resistance of bacteria to antimicrobial medicines is a global issue and a d... more BackgroundThe growing resistance of bacteria to antimicrobial medicines is a global issue and a direct threat to human health. Despite this, antibiotic prophylaxis is often still routinely used in dental implant surgery to prevent bacterial infection and early implant failure, despite unclear benefits. There is a lack of sufficient evidence to formulate clear clinical guidelines and therefore there is a need for well‐designed, large‐scale randomized controlled trials to determine the effect of antibiotic prophylaxis.PurposeTo compare the effect of a presurgical antibiotic regimen with an identical placebo regimen in healthy or relatively healthy patients receiving dental implants.Materials and MethodsThe 474 patients participating in the study were recruited from seven clinics in southern Sweden. We randomized the patients into a test and a placebo group; the study was conducted double‐blinded. Preoperatively, the test group received 2 g of amoxicillin and the control group, identical placebo tablets. The primary outcome was implant failure; secondary outcomes were postoperative infections and adverse events. Patients were evaluated at two follow‐ups: at 7–14 days and at 3–6 months.ResultsPostoperative evaluations of the antibiotic (n = 238) and the placebo (n = 235) groups noted implant failures (antibiotic group: six patients, 2.5% and placebo group: seven patients, 3.0%) and postoperative infections (antibiotic group: two patients, 0.8% and placebo group: five patients, 2.1%). No patient reported any adverse events. Between‐group differences in implant failures and postoperative infections were nonsignificant.ConclusionAntibiotic prophylaxis in conjunction with implant placement is likely of small benefit and should thus be avoided in most cases, especially given the unabated growth in antibiotic‐resistant bacteria. Clinical trial registration number: NCT03412305.
1. Female adult rats were subjected to sympathetic denervation of the parotid glands by bilateral... more 1. Female adult rats were subjected to sympathetic denervation of the parotid glands by bilateral removal of the superior cervical ganglion 10-12 days before acute experiments. The sympathectomy was in some of the experimental groups combined with either bilateral adrenal medullectomy, treatment with the sensory neurotoxin capsaicin or parasympathetic denervation of the gland by cutting the auriculotemporal nerve. 2. Food but not water was withheld for 29-32 h before acute experiments. All animals were given an intraperitoneal injection of phentolamine (2 mg kg-1) and propranolol (1 mg kg-1) and, when appropriate, also atropine (1 mg kg-1). Then the experimental animals were fed their ordinary food of hard chow for 60-90 min. Thereafter, these animals and their non-fed controls were killed, and the parotid glands were removed and used for either morphometric assessment or measurement of amylase activity. 3. In the atropinized rats subjected to sympathectomy alone, eating reduced the numerical density of acinar secretory granules by 50% and the total activity of amylase by 55%; the corresponding figures were, when sympathectomy was combined with adrenal medullectomy, 51 and 63%. Also, in atropinized animals subjected to sympathectomy and capsaicin pretreatment, eating reduced the numerical density of acinar granules and the total amylase activity, in this case by 45 and 35%, respectively. 4. In the atropinized rats subjected to sympathectomy and parasympathectomy, eating caused no change in the numerical density of acinar granules but reduced the total amylase activity by 35%. 5. In the non-atropinized rats subjected to sympathectomy alone, eating reduced the numerical density of acinar granules by 22%, while there was no change in the total amylase activity. 6. In conclusion, eating evoked a reflex activation of the sympathectomized parotid gland that engaged non-adrenergic non-cholinergic receptors of the acinar cells. The present results give weight to a physiological role for non-adrenergic non-cholinergic parasympathetic mechanisms in salivary secretion under reflex conditions.
Clinical Implant Dentistry and Related Research, Jan 24, 2022
BackgroundThe growing resistance of bacteria to antimicrobial medicines is a global issue and a d... more BackgroundThe growing resistance of bacteria to antimicrobial medicines is a global issue and a direct threat to human health. Despite this, antibiotic prophylaxis is often still routinely used in dental implant surgery to prevent bacterial infection and early implant failure, despite unclear benefits. There is a lack of sufficient evidence to formulate clear clinical guidelines and therefore there is a need for well‐designed, large‐scale randomized controlled trials to determine the effect of antibiotic prophylaxis.PurposeTo compare the effect of a presurgical antibiotic regimen with an identical placebo regimen in healthy or relatively healthy patients receiving dental implants.Materials and MethodsThe 474 patients participating in the study were recruited from seven clinics in southern Sweden. We randomized the patients into a test and a placebo group; the study was conducted double‐blinded. Preoperatively, the test group received 2 g of amoxicillin and the control group, identical placebo tablets. The primary outcome was implant failure; secondary outcomes were postoperative infections and adverse events. Patients were evaluated at two follow‐ups: at 7–14 days and at 3–6 months.ResultsPostoperative evaluations of the antibiotic (n = 238) and the placebo (n = 235) groups noted implant failures (antibiotic group: six patients, 2.5% and placebo group: seven patients, 3.0%) and postoperative infections (antibiotic group: two patients, 0.8% and placebo group: five patients, 2.1%). No patient reported any adverse events. Between‐group differences in implant failures and postoperative infections were nonsignificant.ConclusionAntibiotic prophylaxis in conjunction with implant placement is likely of small benefit and should thus be avoided in most cases, especially given the unabated growth in antibiotic‐resistant bacteria. Clinical trial registration number: NCT03412305.
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