Week 8: L1 Anatomy of Maxillary First Pre-molar PDF

**[Week 8]** **L1- Anatomy of Maxillary First Pre-molar** **Presentation** - 4^th^ tooth from the midline - FDI:14,24 - In form and function reflexes transition between the canine and molars - Performs similar function within the mouth to the canine-assists as a prehensile (tea...

**[Week 8]** **L1- Anatomy of Maxillary First Pre-molar** **Presentation** - 4^th^ tooth from the midline - FDI:14,24 - In form and function reflexes transition between the canine and molars - Performs similar function within the mouth to the canine-assists as a prehensile (tearing) tooth - Presents with 2 cusps- buccal and palatal orientation - Mostly two roots- same orientation as cusps - Premolar crowns and roots are smaller than the canines **Development** - First sign of calcification-1.5 years - Crown completed- 5-6 years - Erupts- 10-11 years - Replaces the primary 1^st^ molar in the arch - This is a succedaneous tooth **Buccal aspect** - Bell shaped, similar to canine, but smaller - Buccal surface is convex in all directions - Cervical line less curved - Tip of buccal cusp is located distally to the midline and separates the occlusal border into a long straight mesial ridge and a short rounded distal ridge - Mesial slope of the cusp is longer than the distal - Distal slope is shorter and rounder - Broad longitudinal ridge extends from cusp tip to cervical line-buccal ridge - Buccal cusp is larger mesiodistally and usually 1mm longer than the palatal **Palatal aspect** - Palatal aspect is similar to the buccal - Palatal cusp smaller than the buccal in all dimensions-buccal is visible from the palatal - The palatal root tends to be more blunt than the buccal **Occlusal aspect** - Kite shaped-well defined outline - Presents with a distinctive central developmental groove - This groove usually travels over the mesial marginal ridge - Buccal cusp is larger - BP dimension much greater than MD **Mesial aspect** - Two roots visible: buccal and palatal - Cervical line much less curved - Palatal cusp shorter than buccal - Mesial developmental depression (on the crown and root) - Mesial marginal ridge is marked by mesial marginal developmental groove. This runs from the mesial of the occlusal over the ridge and down the occlusal 1/3 to the mid 1/3 of the M surface - Contact area is mid 1/3 **Distal** - Smaller than the mesial aspect - Similar in outline - Cervical line straight - No concavity present on distal aspect of crown or root - Contact surface in the mid 1/3 **Root structure** - Usually two roots, bifurcation may not be complete - Root trunk makes half of it - Often delicate and curved - When not bifurcated-compressed on both mesial and distal surfaces **Dr Sfera L2- Maxillary second premolar** **Presentation** - FDI- 15 and 25 - Very similar in appearance to Mx 1^st^ premolar - Presentation with two cusps: buccal and palatal orientation but most likely with only one root - Complements 1^st^ Mx premolar in function - Rounder, less angular appearance - Single root - Stronger and heavier tooth - Occlusally more wrinkled appearance - May be congenitally missing **Development** - First sign of Calcification- 2-2.5 years - Crown complete- 6-7 years - Erupt- 10-12 years - Replaces the 2^nd^ deciduous molar - Last of the succedaneous teeth **Buccal and palatal aspects** - Buccal cusp less pointed and shorter than in 1^st^ Mx pre-molar - Less of the buccal cusp visible from the palatal in Mx 1^st^ = palatal cusp is bigger - Might appear thicker in the cervical portion - Buccal ridge less prominent - Mesial slope is shorter **Mesial and distal aspects** - Usually no Mesial developmental groove present over marginal ridge - No Mesial developmental depression but developmental depression might be present on root - Cusps appear shorter and nearly of the same height **Occlusal aspect** - Occlusal outline is more rounded (ovoid) - Cusps are further apart bucco-palatally - Central developmental groove shorter and more irregular - More supplementary grooves give the tooth a more wrinkled appearance **Root structure** - Usually presents with one root and single pulp chamber **Dr Sfera L3- Mandibular 1^st^ premolar** **Presentation** - 4^th^ tooth from midline - FDI-34 and 44 - The smallest premolar - 1^st^ of the posterior Md teeth - Two cusps- buccal and lingual (small, afunctional) and usually one root - There is a transverse ridge that extends from buccal cusp tip to lingual cusp tip **Development** - First sign of calc- 2 years - Crown complete- 5-6 years - Erupt -- 10-12 years - Develop from 4 lobes- 3 buccal one lingual - Replace Md 1^st^ primary molar **Buccal aspect** - Convex mesio-distally and cervico-occlusally - Symmetrical - Large and sharp buccal cusp, similar to lower canine - Characteristics of canine and 2^nd^ premolar - Mid lobe most developed - Mesial cusp ridge is shorter than the distal - Single root is ovoid in shape generally much shorter than in canine **Lingual aspect** - Crown tapers lingually - Lingual cusp small, pointed and afunctional - Most of the buccal cusp is visible from the lingual aspect - The crown is lingually inclined- differs from other pre-molars with the lingual inclination of the occlusal plane - Marginal ridges pronounced on the occlusal - Mesio-lingual developmental groove crosses from the occlusal onto the lingual **Proximal aspects** - Buccal cusps tip is directly in line with the apex of the tooth - Mesiolingually groove is visible only on the mesial aspect - Distal marginal ridge is more developed and positioned higher than the mesial - Contact areas levelled near the centre of the crown (mid 1/3) - Cervical lines curves very slightly **Salient features** **Dr Sfera L4- Md 2^nd^ premolar** **Presentation** - 5^th^ tooth from the midline - FDI- 35 and 45 - Larger than the 1^st^ premolar and functions similarly to a molar - Can present with 2 cusps buccal and lingual or 3 cusps, 1 buccal and 2 lingual - Usually single root **Development** - First sign of calc- 2.5 years - Crown complete- 6-7 years - Erupt- 11-12 years - Succedaneous tooth for Md second primary molar - Develop from either 4 or 5 lobes - When 3 cusp presentation-develops from 3 buccal and 2 lingual lobes - Can be congenitally missing - 2 common occlusal forms: 2-cusp and 3-cusp - Usually, single root is present with a distal inclination - Larger, stronger and longer root than Md 1^st^ - Buccal and lingual cusps closer in height than in Md 1^st^ **Buccal and lingual aspect** - Shorter buccal cusp than that of the 1^st^ premolar - Buccal cusp tip is displaced toward the mesial - Lingual cusp(s)-larger than in 1^st^ premolar - 3 cusps form has a lingual developmental groove between the 2 cusps **Lingual aspect** - 2 cusps has only one lingual cusp - Lingual cusp is smaller than buccal cusp but larger than lingual cusp of Md 1^st^ premolar - No mesiolingual developmental groove present **Proximal surfaces** - Similar in appearance - Convex surfaces in both directions - Distal marginal ridge is lower than the mesial marginal ridge - Broad proximal contact area in the mid 1/3 of the crown - Quite straight cervical outline **Dr Sfera L5- Mx First permanent molar** **Presentation** - First of the molar teeth - FDI: 16 and 26 - Well developed occlusal surface with four well defined cusps - Presents with three well developed large roots: palatal, mesio-buccal and disto-buccal - Present with 3 major cusps, 1 minor cusp and often 1 supplementary cusp-cusp of carabelli - Orientation- 2 buccal and 2 palatal - supplementary cusp, if present, is on the palatal surface of the mesiopalatal cusp (in about 60% of teeth) **Development** - First evidence of calcification around birth - Crown is complete around 3 years old - Erupt at 6 years old - This first permanent teeth in the upper arch - This is a non-succedaneous tooth **Occlusal aspect** - Rhomboidal in outline - Oblique ridge extends from distobuccal cusp to mesiopalatal cusp - Distal to this ridge is the distopalatal groove- extends over the occlusal and onto the palatal aspect often terminating in a pit - Mesial side is larger than the distal **Upper first molar** - 2 major fossae: central and distal - 2 minor fossae: mesial triangular and distal triangular - Central developmental pit lies in the central fossa - Distinct developmental grooves **Buccal aspect** - Outline of the crown roughly trapezoidal - Buccal groove separates the 2 cusps. This extends to midpoint on buccal aspect and may end in a pit. It is a shallow groove - Mesiobuccal cusp is larger, the disto buccal is sharper and longer - Palatal cusps are visible from this aspect - All 3 roots visible: mesio-buccal root is bigger than the disto-buccal root **Palatal aspect** - Palatal aspect obscures the buccal cusps from view - Mesiopalatal is the largest cusp - Cusp of carabelli; if present is located here on the mid to occlusal 1.3 - All 3 roots visible, with the palatal conical and continuous with the cervical part of the crown **Proximal aspects** - Increased bucco-palatal dimension compared to anterior teeth and premolars - Distal marginal ridge is lower or closer to the cervical aspect than the mesial - Distal aspect is more convex than the mesial - Contact area is located toward the buccal aspect on the mesial side and is centrally located on the distal side at the junction of the middle and occlusal 1/3 **Root structure** - Trifurcated root system, palatal root is largest - Roots are widely divergent - Mesiobuccal root is broader than the distobuccal root **Dr Sfera L6- Mx second and third molars** **Presentation** - FDI 17 and 27 - Slightly smaller than the 1^st^ Mx molar - Shows similar features to the Mx 1^st^ molar - Supplements the function of the 1^st^ Mx molar - Show more variation in form than the 1^st^ Mx molar and more supplementary grooves and pits **Development** - First sign of calc- 2.5 years - Crown completed- 7-8 years - Erupt- 11-12 years **Occlusal outline** - Can be similar to Mx 1^st^ molar but more rhomboidal - Similar to 3^rd^ Mx molar- heart shaped - Oblique ridge is less prominent on 17 and 27 - Bucco-palatal dimension similar to 1^st^ Mx molar - More supplemental grooves **Buccal and Palatal aspects** - Cusps not as long as 1^st^ molar Mx - Buccal groove present - Mesiobuccal cusp is larger - Mesiopalatal cusp is visible - Roots not as divergent - Similar in view to 1^st^ Mx molar - Distopalatal cusp is quite small - Occlusopalatal groove often not as developed - Usually no cusp of carabelli present **Proximal** - Crown appears shorter - Contact area is centrally located in the mid third for both aspects - Distal marginal ridge is located more cervically than the mesial ridge - Smaller distobuccal root than the mesiobuccal root - Roots less divergent but as long as in 1^st^ molar **Mx 3^rd^ molars- presentation** - FDI 18 and 28 - Complement the set of upper permanent molars in form and function - If present may show a great range of variation in form **Development** - First sign of Calc- 7-9 years - Crown complete- 12-16 years - Erupt- 18-25 years **Mx 3^rd^ molars** - 3^rd^ molars are often impacted and displaced - May be congenitally missing - Display the greatest variation in form of all teeth - 3^rd^ Mx molar is smaller than the 2^nd^ Mx molar - Roots are shorter than the 2^nd^ Mx molar - Roots are shorter and often fused - Crown is smaller, often triangular or heart shaped - Lots of supplemental grooves **Dr Sfera L7- Md First molar** **Presentation** - Share the same traits as maxillary molars- largest in the arch - FDI:46 and 36 - Present with five cusps and two roots - This is likely the largest tooth in dentition - Accessional - 2 buccal and 2 lingual major cusps - Two roots: mesial and distal orientation - Roots inclined distally - Crown height is smaller than that of premolar but every other measurement is larger **Development** - Generally, erupt before maxillary molars - First evidence of calcification- birth - Crown complere- 3 years - Erupt- 6 years - Root completion- 9-10 years **Occlusal aspect** - Mesiobuccal cusp is the largest - Buccal side is wider than lingual - Mesial marginal ridge is flatter than distal - 2 lingual cusps- approx. same size - Distral cusp-smallest - Developmental grooves travel over occlusal and onto buccal aspect - 3 major occlusal pits- central, mesial and distal **Buccal aspect** - Surface is convex - Mesiobuccal cusp is the largest - Cervical line is almost straight - Buccal cusps are inclined occlusally - Lingual cusps visible from buccal aspect - Occlusal developmental grooves travel over the buccal marginal ridge and often terminate in a pit - Roots originate from single root stem/trunk - Widely splayed roots provide good anchorage in the mouth **Lingual aspect** - Cusps are straighter sharper and taller - Cusps are almost of equal size - Lingual developmental groove separates the two cusps - Bifurcation of roots begins directly beneath this developmental groove - Bifurcation of roots begins directly beneath this developmental groove **Proximal** - Mesial 1. Contact area is in mid 1/3 and slightly higher than on the distal 2. Higher marginal ridge 3. Only 2 cusps visible from this aspect - Distal 1. Distal marginal ridge is lower-more cervically placed than the mesial 2. Contact area is in mid 1/3 **Dr Sfera L8- Md 2^nd^ and 3^rd^ molars** **Presentation 2^nd^** - FDI- 37 and 47 - 4 cusps of equal size: 2 buccal and 2 lingual - 2^nd^ in the moalr series and thus presents with more supplementay grooves - Slightly smaller occluso-cervically than the 1^st^ Md molar **Development** - First evidence of calc- 2.5-3 years - Crown complete- 7-8 years - Erupt- 11-13 years  **Buccal aspect** - 2 buccal cusps visible: separated by buccal groove - This may/may not terminate in a pit - Buccal surface has lingual inclination - Mesio-distal dimension smaller than in 1^st^ Md molar - Two roots visible: mesial and distal- often have distal inclination - They bifurcate from a short root trunk **Lingual aspect** - Root trunk is bifurcated close to the cervical line - Two lingual cusps are of similar size - Mesiolingual cusp is slightly higher than the distal - Roots are shorter and closer together than those of the Md 1^st^ molar **Proximal aspects** - Mesial 1. Contact area is mid 1/3 2. Mesial root is broader than the distal - Distal 1. Contact area is in the mid 1/3 2. Distal root is smaller than the mesial 3. Distal aspect is more convex than the mesial **Md 3^rd^ permanent molars** - May often be impacted - May be congenitally missing - Display the most degree of occlusal variation - Occlusal aspect presents with a large number of supplemental grooves - Contact point is on the mid 1/3 of mesial aspect - Smallest of the lower molars **Md 3^rd^ molar** - FDI- 38 and 48 - Crown morphology is variable - Root structure shorter than those of 2^nd^ molar - Often roots are fused and have a distinct distal inclination - Mesial margin is straighter - Distal aspect is curved **Development** - First evidence of calc- 8-10 years - Crown complete- 12-16 years - Erupt- 17-25 years **Dr Pierce L1- Renal system and disorders** **Function** - Excretion of metabolic waste products - Excretion of foreign chemicals (including drugs)\ regulation of water balance - Regulation of electrolyte salt conc - Regulation of acid-base balance - Regulation of arterial blood pressure - Secretion, metabolism and excretion of hormones - Gluconeogenesis **Structure of nephron** - 1 million in each kidney- basic functional unit - Filters blood and produces urine - Two major parts 1. Corpuscle- (glomerulus and glomerular capsule) and renal tubule 2. Corpuscle filters blood; tubule modifies filtrate  A diagram of a human body Description automatically generated **Glomerular filtration barrier** - Glomerular 3-layer filtration barrier facilitating filtration- relatively impermeable to proteins impermable to proteins and cellular elements of blood - Passive, mostly non-selective process - Fluids and solutes forced through membrane by hydrostatic pressure - Doest not require metabolic energy-simple mechanical filtration - Filtrate- water, salts, nutrients, metabolic wastes- all blood cells and plasma proteins  **The renal tubule** - Proximal convoluted tubule - Nephron loop - Distal convoluted tubule - Collecting duct - Modifies glomerular filtrate by two basic processes-tubular reabsorption and tubular secretion **Transport maximum for reabsorption** - Limit to the rate at which the substance can be transported due to saturation of the specific transport systems **Example glucose:** - At high blood levels, amount of glucose filtered exceeds kidneys ability to reabsorb it- lost in urine - Normal load for glucose= 120mg/min - Transport maximum=320mg/min (some will appear in urine before this) **Tubular secretion** Addition of substances from plasma in peritubular capillaries to the filtrate - Accounts for the appearance of significant amounts of K+ and H+ (pH regulation) in the urine - Proximal tubule an important site for secretion of organic acids and bases (bile salts, oxalate, uric acid etc.)-metabolic end products that must be rapidly removed from the body - Also includes drugs or toxins (e.g. penicillin), thereby rapidly clearing these substances from the blood **Summary of tubular reabsorption and secretion** **Reabsorption** - Removes useful substances from the glomerular filtrate and returns them to the blood - Coupled with water reabsorption - Proximal convoluted tubule is primary site **Secretion** - Transfers unwanted substances from blood and tubule cells into tubular fluid - Most secretion occurs in the proximal convoluted tubule **Regulation of urine volume and osmolarity** - Osmolarity=measure of solute to water ratio - Urine volume and composition must be regulated to maintain fluid and salt balance - Conservation of water-low volumes of concentrated urine (0.5L and 1400mOsm/L) - Removal of excess water-large volumes of dilute urine (up to 20L/day and 50mOsm/L) - Key structure- Nephron loop - Key hormone-ADH **ADH** - Distal tubules and collecting custs normally impermeable to water - During ADH release, distal tubules and collecting ducts become permeable to water due to aquaporins - ADH combined with high salt concentration in surrounding medulla=significant reabsorption and generation of small volumes of concentrated urine **Formation of dilute urine** - Active reabsorption of NaCl from ascending limb of nephron loop-tubular fluid becomes very dilute - Further dilution of tubuluar fluid in distal tubules and collecting ducts by reabsorption of more NaCl and the failure to reabsorb water at low ADH levels. 1. Large volume of dilute urine - Low ADH levels- formation of dilute urine **Formation of concentrated urine** - Active reabsorption of NaCl from ascending limb of nephron loop generates very high solute concentration in medulla 1. Driving force for water reabsorption in presence of high ADH 2. Fluid leaving nephron loop is dilute but becomes concentrated as water is absorbed from distal tubules and collecting ducts due to ADH 3. High ADH levels- urine osmolarity is similar to osmolarity of medullary interstitial fluid (about 1200mOsm/L) **Regulation of salt excretion** - Reabsorption of salt in distal tubule under hormonal control-aldosterone - Influences how much salt is lost in urine or retained in body - Because aldosterone controls excretion of BOTH Na+ and K+, Na+ and K+ levels are inextricably linked - High aldosterone levels- reabsorption of Na+ in exchange of secretion of K+ - Low aldosterone levels-secretion of Na+ in exchange for reabsorption of K+ **Renin-angiotensin system** **Critical regulator of blood volume and vascular resistance** - Control of decreased blood volume and vascular resistance - Control of decreased arterial pressure 1. Short-term via baroreceptors 2. Long term via renin-angiotensin system - Three major compounds: renin, angiotensin 11, aldosterone-act together to elevate arterial pressure in response to decreased renal blood pressure, decreased salt delivery to the distal tubule, and/or beta agonism - Elevates BP long term by modulating blood volume, sodium reabsorption, potassium secretion, water reabsorption and vascular tone - Involves kidneys, lungs, systemic vasculature and the brain  **Renin-angiotensin system continued** - Renin cleaves angiotensin into angiotensin 1 - Angiotensin 1 physiologically inactive but precursor for angiotensin11 - Angiotensin-converting enzyme catalyses conversion of angiotensin 1 into angiotensin 2 **Angiotensin 11 effects** - Stimulates Na+, H+ exchange in proximal convoluted tubule, increasing sodium reabsorption (rapid effect) - Stimulates aldosterone release-increased NaCl and water reabsorption from distal tubule and collecting duct - Causes potent arteriolar vasoconstriction - In the brain 1. Binds to hypothalymus to stimulate thirst and increase water intake 2. Stimulars release of ADH 3. Decreases sensitivity of the baroreceptor reflex- diminished response to blood pressure increases **Net effect**- increase in total sodium, total water and vascular tone=increased blood pressure **Aldosterone** - Major influence on the regulation of Na+ levels in extracellular fluid - Irrespective of aldosterone levels, 65% of filtered Na+ reabsorbed from proximal tubules and another 25% reclaimed in nephron loop - High aldosterone-essentially all the remaining Na+ (NaCl) reabsorbed in distal tubules and collecting ducts - Water will follow Na+ if ADH is also released - Inhibited aldosterone release- virtually no Na+ reabsorption in distal tubule-excretion of large amounts of Na+ along with water - Most important trigger for aldosterone release is the renin-angiotensin mechanism - Aldosterone release also directly stimulated by increase in level of extracellular K+ ions **Dr Touraj- L1- Amalgam** **Thermal properties** - Specific heat (Cp) is the heat energy required to increase the temperature of a unit volume by 1 degree - Thermal conductivity (K) is the rate of transportation of heat (cal or J) through material per unit temperature gradient - Thermal diffusivity (h) is the rate of rise of temperature at one point due to heat source at another point, which depends on thermal conductivity and specific heat. It is most relevant in dental applications. h=K/CpP (P stands for density) **Other thermal properties of dental materials** - Exothermic reaction is most significant in resin-based dental materials. Exothermic reaction in combination with light-cure generated heat may raise the temperature up to 20 degrees - A temperature rise in the tooth pulp of 5.5 degrees or more can be harmful - Coefficient of thermal expansion: fractional increase in the dimension of a body as a function of increased temperature - Due to transient nature of thermal stimuli the expansion and contraction of dental materials is a function of thermal diffusivity and coefficient of thermal expansion **Degradation** - Metals i. Tarnish- surface disscolouration due to the formation of soft and hard surface deposits e.g. sulphides and chlorides ii. Corrosion- degradation of the material properties leading to: structural break down, leaching out cytotoxic or allergic elements, tissue discolouration 1. Chemical corrosion a. Dry corrosion- An unstable oxide surface will fake off and corrosion will continue. This process is self-limiting in some metals where a stable surface oxide forms. b. wet corrosion- electrolyte reactions in an electrolytic cell. Corrosion happens at anode where an electronegative metal is placed in the electrolyte 2. Stress corrosion (chemical + mechanical) 3. Galvanic corrosion- two dissimilar metals are combined 4. Crevice corrosion- sharp crack or fluid filled space 5. Concentration cell corrosion (surface roughness or deep pit and fissures) - Polymers- chain scission, absorption/adsorption, dissolution - Ceramics- hydrolytic attack, dissolution **Consequences of corrosion in the mouth** - Pain due to galvanic effect - Metallic taste due to the release of ions - Deterioration in appearance and mechanical properties - Increased body burden of metallic ions such as nickel and mercury - Tissue discoloration of hard and soft tissue **Elimination of corrosion** - Homogenising treatment of alloys eliminates the possibility of chemical corrosion in metals - Finishing and polishing the surfaces of restoration can eliminate crevice corrosion - Avoiding close contact between dissimilar metals in the mouth to avoid galvanic effects and corrosion **Conventional dental amalgam** \ **Dimensional change of setting reaction** \ **Conventional dental amalgam** Compare with lathe cut - Reach full strength more quickly - Easier to carve and polish - Lower mercury content - Difficult condensation - Creep- Y2 is responsible for high value of creep. Creep may result in ditching **Crevice corrosion and concentration cell corrosion** - Y2 is responsible for high corrosion activity of amalgam - Avoid adjacent or opposing dissimilar metallic restorations - Polishing old amalgam may trigger it **Classification of dental amalgams** - Conventional- lathe cut Ag3Sn and Spherical Ag3Sn - High Cu single phase- All spherical AgSnCu and lathe cut AgSnCu - High Cu admix dispersed phase- Lathe cut Ag3Sn + Spherical AgCu and lathe cut AgSnCu + spherical AgSnCu **Dispersed phase amalgams** Benefits - Reach full strength more quickly - Easier to condense - Easier to carve and polish - Lower mercury content - Higher strength - More resistant to corrosion **Trituration- Mixing ratio** - \%lathe cut alloy=%mercury - \%spherical alloy\>%mercury **Reasons for placement of amalgam restoration** - Main reason- primary caries - Second most reason- secondary caries - Minor reasons- poor margin, restoration fracture and tooth fracture **Marginal breakdown** - Creep and corrosion - Wrong cavo-surface angle - Overfilling - Underfilling/over-carving - Delayed expansion **Recurrent caries- replacement due to recurrent caries** - Amalgam in adults- 72% - Amalgam in children- 56% - Composites- 43% - Poor matrix technique - Poor condensation **Problems with amalgam** - Lack of aesthetics - Non-adhesive - Lack of tensile strength and toughness - Susceptible to corrosion - Lack of biocompatibility - Amalgam bonding reduces marginal leakage and sensitivity **Amalgam safety** - Personal protection - Environmental reasons - Patient protection - Pregnant, breast feeding, children - If amalgam restoration is necessary must minimise exposure to mercury **Mercury Hygiene** - Know the potential sources of mercury contamination 1. Spills 2. Leaky dispensers or capsules 3. Removing or polishing amalgams 4. Sterilising Hg-contaminated instruments - Avoid direct skin contact with dental amalgam - Use high volume evacuation when finishing or removing amalgams - Use rubber dam - Store amalgam scap under radiographic fixer solution in a designated container - Report and clean up spilled mercury immediately using a clean-up kit - Wear professional clothing only in dental surgery - Provide proper ventilation - Monitor mercury vapour levels in the dental surgery - Monitor personnel-e.g. Hg urine level - Use proper work area design - Use an amalgamator fitted cover during trituration